原文鏈接：http://www.reibang.com/p/1ff9e44ccc78

1柑肴、禁止手機(jī)睡眠

[UIApplication sharedApplication].idleTimerDisabled = YES;

2啼染、隱藏某行cell

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
// 如果是你需要隱藏的那一行叔壤，返回高度為0
    if(indexPath.row == YouWantToHideRow)
        return 0; 
    return 44;
}

// 然后再你需要隱藏cell的時(shí)候調(diào)用
[self.tableView beginUpdates];
[self.tableView endUpdates];

3区端、禁用button高亮

button.adjustsImageWhenHighlighted = NO;
或者在創(chuàng)建的時(shí)候
 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];

4榴鼎、tableview遇到這種報(bào)錯(cuò)failed to obtain a cell from its dataSource

是因?yàn)槟愕腸ell被調(diào)用的早了伯诬。先循環(huán)使用了cell，后又創(chuàng)建cell巫财。順序錯(cuò)了
可能原因：1盗似、xib的cell沒有注冊(cè) 2、內(nèi)存中已經(jīng)有這個(gè)cell的緩存了(也就是說通過你的cellId找到的cell并不是你想要的類型)平项，這時(shí)候需要改下cell的標(biāo)識(shí)

5赫舒、cocoa pods報(bào)這個(gè)錯(cuò)誤：unable to access 'https://github.com/facebook/pop.git/': Operation timed out after 0 milliseconds with 0 out of 0 bytes received

解決辦法：原因可能是網(wǎng)絡(luò)問題，網(wǎng)絡(luò)請(qǐng)求超時(shí)了闽瓢，只需要重試就行了

6接癌、cocoa pods 出現(xiàn)ERROR: While executing gem ... (Errno::EPERM)

解決辦法：
https://segmentfault.com/q/1010000002926243

7、動(dòng)畫切換window的根控制器

// options是動(dòng)畫選項(xiàng)
[UIView transitionWithView:[UIApplication sharedApplication].keyWindow duration:0.5f options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
        BOOL oldState = [UIView areAnimationsEnabled];
        [UIView setAnimationsEnabled:NO];
        [UIApplication sharedApplication].keyWindow.rootViewController = [RootViewController new];
        [UIView setAnimationsEnabled:oldState];
    } completion:^(BOOL finished) {

    }];

8扣讼、去除數(shù)組中重復(fù)的對(duì)象

NSArray *newArr = [oldArr valueForKeyPath:@“@distinctUnionOfObjects.self"];

9缺猛、編譯的時(shí)候遇到 no such file or directory: ／users／apple／XXX

是因?yàn)榫幾g的時(shí)候，在此路徑下找不到這個(gè)文件，解決這個(gè)問題荔燎，首先是是要檢查缺少的文件是不是在工程中耻姥，如果不在工程中，需要從本地拖進(jìn)去有咨，如果發(fā)現(xiàn)已經(jīng)存在工程中了咏闪，或者拖進(jìn)去還是報(bào)錯(cuò)，這時(shí)候需要去build phases中搜索這個(gè)文件摔吏，這時(shí)候很可能會(huì)搜出現(xiàn)兩個(gè)相同的文件，這時(shí)候纵装，有一個(gè)路徑是正確的征讲，刪除另外一個(gè)即可。如果刪除了還是不行橡娄，需要把兩個(gè)都刪掉诗箍，然后重新往工程里拖進(jìn)這個(gè)文件即可

image

10、iOS8系統(tǒng)中挽唉，tableView最好實(shí)現(xiàn)下-tableView: heightForRowAtIndexPath:這個(gè)代理方法滤祖，要不然在iOS8中可能就會(huì)出現(xiàn)顯示不全或者無法響應(yīng)事件的問題

11、iOS8中實(shí)現(xiàn)側(cè)滑功能的時(shí)候這個(gè)方法必須實(shí)現(xiàn)瓶籽，要不然在iOS8中無法側(cè)滑

// 必須寫的方法匠童，和editActionsForRowAtIndexPath配對(duì)使用，里面什么不寫也行
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

}

12塑顺、三個(gè)通知

NSSystemTimeZoneDidChangeNotification監(jiān)聽修改時(shí)間界面的兩個(gè)按鈕狀態(tài)變化
UIApplicationSignificantTimeChangeNotification 監(jiān)聽用戶改變時(shí)間 （只要點(diǎn)擊自動(dòng)設(shè)置按鈕就會(huì)調(diào)用） NSSystemClockDidChangeNotification 監(jiān)聽用戶修改時(shí)間（時(shí)間不同才會(huì)調(diào)用）

13汤求、SDWebImage本地緩存有時(shí)候會(huì)害人。如果之前緩存過一張圖片严拒，即使下次服務(wù)器換了這張圖片扬绪，但是圖片url沒換，用sdwebimage下載下來的還是以前那張,所以遇到這種問題裤唠，不要先去懟服務(wù)器挤牛，清空下緩存再試就好了。

14种蘸、上線前注意：

1）墓赴、刪掉代碼中所有的測(cè)試代碼
2）、如果后臺(tái)有審核模式劈彪，提醒后臺(tái)開啟此模式
3）竣蹦、主流程再跑一跑
4）、全局搜索waring沧奴，檢查所有標(biāo)記waring的地方

15痘括、跳進(jìn)app權(quán)限設(shè)置

// 跳進(jìn)app設(shè)置
            if (UIApplicationOpenSettingsURLString != NULL) {
                UIApplication *application = [UIApplication sharedApplication];
                NSURL *URL = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
                if ([application respondsToSelector:@selector(openURL:options:completionHandler:)]) {
                    [application openURL:URL options:@{}
                       completionHandler:nil];
                } else {
                    [application openURL:URL];
                }
            }

16、給一個(gè)view截圖

UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

17、開發(fā)中如果要?jiǎng)討B(tài)修改tableView的tableHeaderView或者tableFooterView的高度纲菌，需要給tableView重新設(shè)置挠日，而不是直接更改高度。正確的做法是重新設(shè)置一下tableView.tableFooterView = 更改過高度的view翰舌。為什么嚣潜？其實(shí)在iOS8以上直接改高度是沒有問題的，在iOS8中出現(xiàn)了contentSize不準(zhǔn)確的問題椅贱，這是解決辦法懂算。

18、注意對(duì)象為nil的時(shí)候庇麦，調(diào)用此對(duì)象分類的方法不會(huì)執(zhí)行

19计技、collectionView的內(nèi)容小于其寬高的時(shí)候是不能滾動(dòng)的，設(shè)置可以滾動(dòng)：

collectionView.alwaysBounceHorizontal = YES;
collectionView.alwaysBounceVertical = YES;

20山橄、設(shè)置navigationBar上的title顏色和大小

    [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

21垮媒、顏色轉(zhuǎn)圖片

+ (UIImage *)cl_imageWithColor:(UIColor *)color {
  CGRect rect = CGRectMake(0.0f, 0.0f, 1.0f, 1.0f);
  UIGraphicsBeginImageContext(rect.size);
  CGContextRef context = UIGraphicsGetCurrentContext();

  CGContextSetFillColorWithColor(context, [color CGColor]);
  CGContextFillRect(context, rect);

  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();

  return image;
}

22、view設(shè)置圓角

#define ViewBorderRadius(View, Radius, Width, Color)\
\
[View.layer setCornerRadius:(Radius)];\
[View.layer setMasksToBounds:YES];\
[View.layer setBorderWidth:(Width)];\
[View.layer setBorderColor:[Color CGColor]] // view圓角

23航棱、強(qiáng)／弱引用

#define WeakSelf(type)  __weak typeof(type) weak##type = type; // weak
#define StrongSelf(type)  __strong typeof(type) type = weak##type; // strong

24睡雇、由角度轉(zhuǎn)換弧度

#define DegreesToRadian(x) (M_PI * (x) / 180.0)

25、由弧度轉(zhuǎn)換角度

#define RadianToDegrees(radian) (radian*180.0)/(M_PI)

26饮醇、獲取圖片資源

#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]

27它抱、獲取temp

#define PathTemp NSTemporaryDirectory()

28、獲取沙盒 Document

#define PathDocument [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject]

29朴艰、獲取沙盒 Cache

#define PathCache [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES) firstObject]

30抗愁、GCD代碼只執(zhí)行一次

#define kDISPATCH_ONCE_BLOCK(onceBlock) static dispatch_once_t onceToken; dispatch_once(&onceToken, onceBlock);

31、自定義NSLog

#ifdef DEBUG
#define NSLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
#define NSLog(...)
#endif

32呵晚、Font

#define FontL(s)             [UIFont systemFontOfSize:s weight:UIFontWeightLight]
#define FontR(s)             [UIFont systemFontOfSize:s weight:UIFontWeightRegular]
#define FontB(s)             [UIFont systemFontOfSize:s weight:UIFontWeightBold]
#define FontT(s)             [UIFont systemFontOfSize:s weight:UIFontWeightThin]
#define Font(s)              FontL(s)

33蜘腌、FORMAT

#define FORMAT(f, ...)      [NSString stringWithFormat:f, ## __VA_ARGS__]

34、在主線程上運(yùn)行

#define kDISPATCH_MAIN_THREAD(mainQueueBlock) dispatch_async(dispatch_get_main_queue(), mainQueueBlock);

35饵隙、開啟異步線程

#define kDISPATCH_GLOBAL_QUEUE_DEFAULT(globalQueueBlock) dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), globalQueueBlocl);

36撮珠、通知

#define NOTIF_ADD(n, f)     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil]
#define NOTIF_POST(n, o)    [[NSNotificationCenter defaultCenter] postNotificationName:n object:o]
#define NOTIF_REMV()        [[NSNotificationCenter defaultCenter] removeObserver:self]

37、隨機(jī)顏色

+ (UIColor *)RandomColor {
    NSInteger aRedValue = arc4random() % 255;
    NSInteger aGreenValue = arc4random() % 255;
    NSInteger aBlueValue = arc4random() % 255;
    UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];
    return randColor;
}

38金矛、獲取window

+(UIWindow*)getWindow {
    UIWindow* win = nil; //[UIApplication sharedApplication].keyWindow;
    for (id item in [UIApplication sharedApplication].windows) {
        if ([item class] == [UIWindow class]) {
            if (!((UIWindow*)item).hidden) {
                win = item;
                break;
            }
        }
    }
    return win;
}

39芯急、修改textField的placeholder的字體顏色、大小

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

40驶俊、統(tǒng)一收起鍵盤

[[[UIApplication sharedApplication] keyWindow] endEditing:YES];

41娶耍、控制屏幕旋轉(zhuǎn)，在控制器中寫

/** 是否支持自動(dòng)轉(zhuǎn)屏 */
- (BOOL)shouldAutorotate {
    return YES;
}

/** 支持哪些屏幕方向 */
- (UIInterfaceOrientationMask)supportedInterfaceOrientations {
    return UIInterfaceOrientationMaskLandscapeLeft | UIInterfaceOrientationMaskLandscapeRight;
}

/** 默認(rèn)的屏幕方向（當(dāng)前ViewController必須是通過模態(tài)出來的UIViewController（模態(tài)帶導(dǎo)航的無效）方式展現(xiàn)出來的饼酿，才會(huì)調(diào)用這個(gè)方法） */
- (UIInterfaceOrientation)preferredInterfaceOrientationForPresentation {
    return UIInterfaceOrientationLandscapeLeft | UIInterfaceOrientationLandscapeRight;
}

42榕酒、獲取app緩存大小

- (CGFloat)getCachSize {

    NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];
    //獲取自定義緩存大小
    //用枚舉器遍歷 一個(gè)文件夾的內(nèi)容
    //1.獲取 文件夾枚舉器
    NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
    NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];
    __block NSUInteger count = 0;
    //2.遍歷
    for (NSString *fileName in enumerator) {
        NSString *path = [myCachePath stringByAppendingPathComponent:fileName];
        NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];
        count += fileDict.fileSize;//自定義所有緩存大小
    }
    // 得到是字節(jié)  轉(zhuǎn)化為M
    CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;
    return totalSize;
}

43胚膊、清理app緩存

- (void)handleClearView {
    //刪除兩部分
    //1.刪除 sd 圖片緩存
    //先清除內(nèi)存中的圖片緩存
    [[SDImageCache sharedImageCache] clearMemory];
    //清除磁盤的緩存
    [[SDImageCache sharedImageCache] clearDisk];
    //2.刪除自己緩存
    NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
    [[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}

44、模型轉(zhuǎn)字典

static NSSet *classes;

- (NSMutableDictionary *)getParameterDictionary {

    NSMutableDictionary *dict = [NSMutableDictionary dictionary];

    Class c = self.class;

    while (c) {
        unsigned count;
        objc_property_t *properties = class_copyPropertyList([c class], &count);

        for (int i = 0; i < count; i++) {
            NSString *key = [NSString stringWithUTF8String:property_getName(properties[i])];
            dict[key] = [self valueForKey:key];
        }
        free(properties);

        // 獲得父類
        c = class_getSuperclass(c);

        if ([self isClassFromFoundation:c]) break;
    }
    return dict;
}

- (BOOL)isClassFromFoundation:(Class)c
{
    if (c == [NSObject class] || c == [NSManagedObject class]) return YES;

    __block BOOL result = NO;
    [[self foundationClasses] enumerateObjectsUsingBlock:^(Class foundationClass, BOOL *stop) {
        if ([c isSubclassOfClass:foundationClass]) {
            result = YES;
            *stop = YES;
        }
    }];
    return result;
}

- (NSSet *)foundationClasses
{
    if (classes == nil) {
        // 集合中沒有NSObject想鹰，因?yàn)閹缀跛械念惗际抢^承自NSObject紊婉，具體是不是NSObject需要特殊判斷
        classes = [NSSet setWithObjects:
                              [NSURL class],
                              [NSDate class],
                              [NSValue class],
                              [NSData class],
                              [NSError class],
                              [NSArray class],
                              [NSDictionary class],
                              [NSString class],
                              [NSAttributedString class], nil];
    }
    return classes;
}

45、交換兩個(gè)方法實(shí)現(xiàn)

Class aClass = [self class]; 

        SEL originalSelector = @selector(viewWillAppear:); 
        SEL swizzledSelector = @selector(xxx_viewWillAppear:); 

        Method originalMethod = class_getInstanceMethod(aClass, originalSelector); 
        Method swizzledMethod = class_getInstanceMethod(aClass, swizzledSelector); 

        BOOL didAddMethod = 
            class_addMethod(aClass, 
                originalSelector, 
                method_getImplementation(swizzledMethod), 
                method_getTypeEncoding(swizzledMethod)); 

        if (didAddMethod) { 
            class_replaceMethod(aClass, 
                swizzledSelector, 
                method_getImplementation(originalMethod), 
                method_getTypeEncoding(originalMethod)); 
        } else { 
            method_exchangeImplementations(originalMethod, swizzledMethod); 
        } 

46辑舷、打印百分號(hào)和引號(hào)

    NSLog(@"%%");
    NSLog(@"\"");

47喻犁、幾個(gè)常用權(quán)限判斷

    if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {
        NSLog(@"沒有定位權(quán)限");
    }
    AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (statusVideo == AVAuthorizationStatusDenied) {
        NSLog(@"沒有攝像頭權(quán)限");
    }
    //是否有麥克風(fēng)權(quán)限
    AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];
    if (statusAudio == AVAuthorizationStatusDenied) {
        NSLog(@"沒有錄音權(quán)限");
    }
    [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
        if (status == PHAuthorizationStatusDenied) {
            NSLog(@"沒有相冊(cè)權(quán)限");
        }
    }];

48、獲取手機(jī)型號(hào)

    + (NSString *)getDeviceInfo {
    struct utsname systemInfo;
    uname(&systemInfo);
    NSString *platform = [NSString stringWithCString:systemInfo.machine encoding:NSASCIIStringEncoding];
    if ([platform isEqualToString:@"iPhone1,1"]) return @"iPhone 2G";
    if ([platform isEqualToString:@"iPhone1,2"]) return @"iPhone 3G";
    if ([platform isEqualToString:@"iPhone2,1"]) return @"iPhone 3GS";
    if ([platform isEqualToString:@"iPhone3,1"]) return @"iPhone 4";
    if ([platform isEqualToString:@"iPhone3,2"]) return @"iPhone 4";
    if ([platform isEqualToString:@"iPhone3,3"]) return @"iPhone 4";
    if ([platform isEqualToString:@"iPhone4,1"]) return @"iPhone 4S";
    if ([platform isEqualToString:@"iPhone5,1"]) return @"iPhone 5";
    if ([platform isEqualToString:@"iPhone5,2"]) return @"iPhone 5";
    if ([platform isEqualToString:@"iPhone5,3"]) return @"iPhone 5c";
    if ([platform isEqualToString:@"iPhone5,4"]) return @"iPhone 5c";
    if ([platform isEqualToString:@"iPhone6,1"]) return @"iPhone 5s";
    if ([platform isEqualToString:@"iPhone6,2"]) return @"iPhone 5s";
    if ([platform isEqualToString:@"iPhone7,1"]) return @"iPhone 6 Plus";
    if ([platform isEqualToString:@"iPhone7,2"]) return @"iPhone 6";
    if ([platform isEqualToString:@"iPhone8,1"]) return @"iPhone 6s";
    if ([platform isEqualToString:@"iPhone8,2"]) return @"iPhone 6s Plus";
    // 日行兩款手機(jī)型號(hào)均為日本獨(dú)占何缓，可能使用索尼FeliCa支付方案而不是蘋果支付
    if ([platform isEqualToString:@"iPhone9,1"])    return @"國(guó)行肢础、日版、港行iPhone 7";
    if ([platform isEqualToString:@"iPhone9,2"])    return @"港行碌廓、國(guó)行iPhone 7 Plus";
    if ([platform isEqualToString:@"iPhone9,3"])    return @"美版乔妈、臺(tái)版iPhone 7";
    if ([platform isEqualToString:@"iPhone9,4"])    return @"美版、臺(tái)版iPhone 7 Plus";
    if ([platform isEqualToString:@"iPhone8,4"]) return @"iPhone SE";
    if ([platform isEqualToString:@"iPod1,1"]) return @"iPod Touch 1G";
    if ([platform isEqualToString:@"iPod2,1"]) return @"iPod Touch 2G";
    if ([platform isEqualToString:@"iPod3,1"]) return @"iPod Touch 3G";
    if ([platform isEqualToString:@"iPod4,1"]) return @"iPod Touch 4G";
    if ([platform isEqualToString:@"iPod5,1"]) return @"iPod Touch 5G";
    if ([platform isEqualToString:@"iPad1,1"]) return @"iPad 1G";
    if ([platform isEqualToString:@"iPad2,1"]) return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,2"]) return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,3"]) return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,4"]) return @"iPad 2";
    if ([platform isEqualToString:@"iPad2,5"]) return @"iPad Mini 1G";
    if ([platform isEqualToString:@"iPad2,6"]) return @"iPad Mini 1G";
    if ([platform isEqualToString:@"iPad2,7"]) return @"iPad Mini 1G";
    if ([platform isEqualToString:@"iPad3,1"]) return @"iPad 3";
    if ([platform isEqualToString:@"iPad3,2"]) return @"iPad 3";
    if ([platform isEqualToString:@"iPad3,3"]) return @"iPad 3";
    if ([platform isEqualToString:@"iPad3,4"]) return @"iPad 4";
    if ([platform isEqualToString:@"iPad3,5"]) return @"iPad 4";
    if ([platform isEqualToString:@"iPad3,6"]) return @"iPad 4";
    if ([platform isEqualToString:@"iPad4,1"]) return @"iPad Air";
    if ([platform isEqualToString:@"iPad4,2"]) return @"iPad Air";
    if ([platform isEqualToString:@"iPad4,3"]) return @"iPad Air";
    if ([platform isEqualToString:@"iPad4,4"]) return @"iPad Mini 2G";
    if ([platform isEqualToString:@"iPad4,5"]) return @"iPad Mini 2G";
    if ([platform isEqualToString:@"iPad4,6"]) return @"iPad Mini 2G";
    if ([platform isEqualToString:@"i386"]) return @"iPhone Simulator";
    if ([platform isEqualToString:@"x86_64"]) return @"iPhone Simulator";
    return platform;
}

49氓皱、長(zhǎng)按復(fù)制功能

- (void)viewDidLoad
{
    [self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];
}
- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {
    if (longPress.state == UIGestureRecognizerStateBegan) {
        UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
        pasteboard.string = @"需要復(fù)制的文本";
    }
}

50、cocoapods升級(jí)

在終端執(zhí)行 sudo gem install -n / usr / local / bin cocoapods --pre

51勃刨、設(shè)置啟動(dòng)頁(yè)后波材，依然顯示之前的

刪除app，手機(jī)重啟身隐，重新安裝

52廷区、判斷圖片類型

//通過圖片Data數(shù)據(jù)第一個(gè)字節(jié) 來獲取圖片擴(kuò)展名
- (NSString *)contentTypeForImageData:(NSData *)data
{
    uint8_t c;
    [data getBytes:&c length:1];
    switch (c)
    {
        case 0xFF:
            return @"jpeg";

        case 0x89:
            return @"png";

        case 0x47:
            return @"gif";

        case 0x49:
        case 0x4D:
            return @"tiff";

        case 0x52:
        if ([data length] < 12) {
            return nil;
        }

        NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
        if ([testString hasPrefix:@"RIFF"]
            && [testString hasSuffix:@"WEBP"])
        {
            return @"webp";
        }

        return nil;
    }

    return nil;
}

53、獲取手機(jī)和app信息

NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];  
 CFShow(infoDictionary);  
// app名稱  
 NSString *app_Name = [infoDictionary objectForKey:@"CFBundleDisplayName"];  
 // app版本  
 NSString *app_Version = [infoDictionary objectForKey:@"CFBundleShortVersionString"];  
 // app build版本  
 NSString *app_build = [infoDictionary objectForKey:@"CFBundleVersion"];  

    //手機(jī)序列號(hào)  
    NSString* identifierNumber = [[UIDevice currentDevice] uniqueIdentifier];  
    NSLog(@"手機(jī)序列號(hào): %@",identifierNumber);  
    //手機(jī)別名： 用戶定義的名稱  
    NSString* userPhoneName = [[UIDevice currentDevice] name];  
    NSLog(@"手機(jī)別名: %@", userPhoneName);  
    //設(shè)備名稱  
    NSString* deviceName = [[UIDevice currentDevice] systemName];  
    NSLog(@"設(shè)備名稱: %@",deviceName );  
    //手機(jī)系統(tǒng)版本  
    NSString* phoneVersion = [[UIDevice currentDevice] systemVersion];  
    NSLog(@"手機(jī)系統(tǒng)版本: %@", phoneVersion);  
    //手機(jī)型號(hào)  
    NSString* phoneModel = [[UIDevice currentDevice] model];  
    NSLog(@"手機(jī)型號(hào): %@",phoneModel );  
    //地方型號(hào)  （國(guó)際化區(qū)域名稱）  
    NSString* localPhoneModel = [[UIDevice currentDevice] localizedModel];  
    NSLog(@"國(guó)際化區(qū)域名稱: %@",localPhoneModel );  

    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];  
    // 當(dāng)前應(yīng)用名稱  
    NSString *appCurName = [infoDictionary objectForKey:@"CFBundleDisplayName"];  
    NSLog(@"當(dāng)前應(yīng)用名稱：%@",appCurName);  
    // 當(dāng)前應(yīng)用軟件版本  比如：1.0.1  
    NSString *appCurVersion = [infoDictionary objectForKey:@"CFBundleShortVersionString"];  
    NSLog(@"當(dāng)前應(yīng)用軟件版本:%@",appCurVersion);  
    // 當(dāng)前應(yīng)用版本號(hào)碼   int類型  
    NSString *appCurVersionNum = [infoDictionary objectForKey:@"CFBundleVersion"];  
    NSLog(@"當(dāng)前應(yīng)用版本號(hào)碼：%@",appCurVersionNum); 

54贾铝、獲取一個(gè)類的所有屬性

id LenderClass = objc_getClass("Lender");
unsigned int outCount, I;
objc_property_t *properties = class_copyPropertyList(LenderClass, &outCount);
for (i = 0; i < outCount; i++) {
    objc_property_t property = properties[I];
    fprintf(stdout, "%s %s\n", property_getName(property), property_getAttributes(property));
}

55隙轻、image圓角

- (UIImage *)circleImage
{
    // NO代表透明
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
    // 獲得上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    // 添加一個(gè)圓
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    // 方形變圓形
    CGContextAddEllipseInRect(ctx, rect);
    // 裁剪
    CGContextClip(ctx);
    // 將圖片畫上去
    [self drawInRect:rect];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

56、image拉伸

+ (UIImage *)resizableImage:(NSString *)imageName
{
    UIImage *image = [UIImage imageNamed:imageName];
    CGFloat imageW = image.size.width;
    CGFloat imageH = image.size.height;
    return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];
}

57垢揩、JSON字符串轉(zhuǎn)字典

+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {
    NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
    return responseJSON;
}

58玖绿、身份證號(hào)驗(yàn)證

- (BOOL)validateIdentityCard {
    BOOL flag;
    if (self.length <= 0) {
        flag = NO;
        return flag;
    }
    NSString *regex2 = @"^(\\d{14}|\\d{17})(\\d|[xX])$";
    NSPredicate *identityCardPredicate = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex2];
    return [identityCardPredicate evaluateWithObject:self];
}

59、獲取設(shè)備mac地址

+ (NSString *)macAddress {
    int                 mib[6];
    size_t              len;
    char                *buf;
    unsigned char       *ptr;
    struct if_msghdr    *ifm;
    struct sockaddr_dl  *sdl;

    mib[0] = CTL_NET;
    mib[1] = AF_ROUTE;
    mib[2] = 0;
    mib[3] = AF_LINK;
    mib[4] = NET_RT_IFLIST;

    if((mib[5] = if_nametoindex("en0")) == 0) {
        printf("Error: if_nametoindex error\n");
        return NULL;
    }

    if(sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 1\n");
        return NULL;
    }

    if((buf = malloc(len)) == NULL) {
        printf("Could not allocate memory. Rrror!\n");
        return NULL;
    }

    if(sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
        printf("Error: sysctl, take 2");
        return NULL;
    }

    ifm = (struct if_msghdr *)buf;
    sdl = (struct sockaddr_dl *)(ifm + 1);
    ptr = (unsigned char *)LLADDR(sdl);
    NSString *outstring = [NSString stringWithFormat:@"%02X:%02X:%02X:%02X:%02X:%02X",
                           *ptr, *(ptr+1), *(ptr+2), *(ptr+3), *(ptr+4), *(ptr+5)];
    free(buf);

    return outstring;
}

60叁巨、導(dǎo)入自定義字體庫(kù)

1斑匪、找到你想用的字體的 ttf 格式，拖入工程
2锋勺、在工程的plist中增加一行數(shù)組蚀瘸，“Fonts provided by application”
3、為這個(gè)key添加一個(gè)item庶橱，value為你剛才導(dǎo)入的ttf文件名
4贮勃、直接使用即可：label.font = [UIFont fontWithName:@"你剛才導(dǎo)入的ttf文件名" size:20.0]；

61苏章、拿到當(dāng)前正在顯示的控制器寂嘉，不管是push進(jìn)去的奏瞬，還是present進(jìn)去的都能拿到

- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {
    if ([vc isKindOfClass:[UINavigationController class]]) {
        return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];
    }else if ([vc isKindOfClass:[UITabBarController class]]){
        return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];
    } else {
        if (vc.presentedViewController) {
            return [self getVisibleViewControllerFrom:vc.presentedViewController];
        } else {
            return vc;
        }
    }
}

62、runtime為一個(gè)類動(dòng)態(tài)添加屬性

// 動(dòng)態(tài)添加屬性的本質(zhì)是: 讓對(duì)象的某個(gè)屬性與值產(chǎn)生關(guān)聯(lián)
        objc_setAssociatedObject(self, WZBPlaceholderViewKey, placeholderView, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

63垫释、獲取runtime為一個(gè)類動(dòng)態(tài)添加的屬性

objc_getAssociatedObject(self, WZBPlaceholderViewKey);

64丝格、KVO監(jiān)聽某個(gè)對(duì)象的屬性

// 添加監(jiān)聽者
[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];

// 當(dāng)監(jiān)聽的屬性值變化的時(shí)候會(huì)來到這個(gè)方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if ([keyPath isEqualToString:@"property"]) {
       [self textViewTextChange];
       } else {
     }
}

65、Reachability判斷網(wǎng)絡(luò)狀態(tài)

NetworkStatus status = [[Reachability reachabilityForInternetConnection] currentReachabilityStatus];
    if (status == NotReachable) {
        NSLog(@"當(dāng)前設(shè)備無網(wǎng)絡(luò)");
    }
    if (status == ReachableViaWiFi) {
        NSLog(@"當(dāng)前wifi網(wǎng)絡(luò)");
    }
    if (status == ReachableViaWWAN) {
        NSLog(@"當(dāng)前蜂窩移動(dòng)網(wǎng)絡(luò)");
    }

66棵譬、AFNetworking監(jiān)聽網(wǎng)絡(luò)狀態(tài)

// 監(jiān)聽網(wǎng)絡(luò)狀況
    AFNetworkReachabilityManager *mgr = [AFNetworkReachabilityManager sharedManager];
    [mgr setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case AFNetworkReachabilityStatusUnknown:
                break;
            case AFNetworkReachabilityStatusNotReachable: {
                [SVProgressHUD showInfoWithStatus:@"當(dāng)前設(shè)備無網(wǎng)絡(luò)"];
            }
                break;
            case AFNetworkReachabilityStatusReachableViaWiFi:
                [SVProgressHUD showInfoWithStatus:@"當(dāng)前Wi-Fi網(wǎng)絡(luò)"];
                break;
            case AFNetworkReachabilityStatusReachableViaWWAN:
                [SVProgressHUD showInfoWithStatus:@"當(dāng)前蜂窩移動(dòng)網(wǎng)絡(luò)"];
                break;
            default:
                break;
        }
    }];
    [mgr startMonitoring];

67显蝌、透明顏色不影響子視圖透明度

    [UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>];

68、取圖片某一點(diǎn)的顏色

    if (point.x < 0 || point.y < 0) return nil;

    CGImageRef imageRef = self.CGImage;
    NSUInteger width = CGImageGetWidth(imageRef);
    NSUInteger height = CGImageGetHeight(imageRef);
    if (point.x >= width || point.y >= height) return nil;

    unsigned char *rawData = malloc(height * width * 4);
    if (!rawData) return nil;

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    NSUInteger bytesPerPixel = 4;
    NSUInteger bytesPerRow = bytesPerPixel * width;
    NSUInteger bitsPerComponent = 8;
    CGContextRef context = CGBitmapContextCreate(rawData,
                                                 width,
                                                 height,
                                                 bitsPerComponent,
                                                 bytesPerRow,
                                                 colorSpace,
                                                 kCGImageAlphaPremultipliedLast
                                                 | kCGBitmapByteOrder32Big);
    if (!context) {
        free(rawData);
        return nil;
    }
    CGColorSpaceRelease(colorSpace);
    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
    CGContextRelease(context);

    int byteIndex = (bytesPerRow * point.y) + point.x * bytesPerPixel;
    CGFloat red   = (rawData[byteIndex]     * 1.0) / 255.0;
    CGFloat green = (rawData[byteIndex + 1] * 1.0) / 255.0;
    CGFloat blue  = (rawData[byteIndex + 2] * 1.0) / 255.0;
    CGFloat alpha = (rawData[byteIndex + 3] * 1.0) / 255.0;

    UIColor *result = nil;
    result = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
    free(rawData);
    return result;

69订咸、判斷該圖片是否有透明度通道

  - (BOOL)hasAlphaChannel
{
    CGImageAlphaInfo alpha = CGImageGetAlphaInfo(self.CGImage);
    return (alpha == kCGImageAlphaFirst ||
            alpha == kCGImageAlphaLast ||
            alpha == kCGImageAlphaPremultipliedFirst ||
            alpha == kCGImageAlphaPremultipliedLast);
}

70曼尊、獲得灰度圖

+ (UIImage*)covertToGrayImageFromImage:(UIImage*)sourceImage
{
    int width = sourceImage.size.width;
    int height = sourceImage.size.height;

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
    CGContextRef context = CGBitmapContextCreate (nil,width,height,8,0,colorSpace,kCGImageAlphaNone);
    CGColorSpaceRelease(colorSpace);

    if (context == NULL) {
        return nil;
    }

    CGContextDrawImage(context,CGRectMake(0, 0, width, height), sourceImage.CGImage);
    CGImageRef contextRef = CGBitmapContextCreateImage(context);
    UIImage *grayImage = [UIImage imageWithCGImage:contextRef];
    CGContextRelease(context);
    CGImageRelease(contextRef);

    return grayImage;
}

71、根據(jù)bundle中的文件名讀取圖片

   + (UIImage *)imageWithFileName:(NSString *)name {
    NSString *extension = @"png";

    NSArray *components = [name componentsSeparatedByString:@"."];
    if ([components count] >= 2) {
        NSUInteger lastIndex = components.count - 1;
        extension = [components objectAtIndex:lastIndex];

        name = [name substringToIndex:(name.length-(extension.length+1))];
    }

    // 如果為Retina屏幕且存在對(duì)應(yīng)圖片脏嚷，則返回Retina圖片骆撇，否則查找普通圖片
    if ([UIScreen mainScreen].scale == 2.0) {
        name = [name stringByAppendingString:@"@2x"];

        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
        if (path != nil) {
            return [UIImage imageWithContentsOfFile:path];
        }
    }

    if ([UIScreen mainScreen].scale == 3.0) {
        name = [name stringByAppendingString:@"@3x"];

        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
        if (path != nil) {
            return [UIImage imageWithContentsOfFile:path];
        }
    }

    NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
    if (path) {
        return [UIImage imageWithContentsOfFile:path];
    }

    return nil;
}

72、合并兩個(gè)圖片

+ (UIImage*)mergeImage:(UIImage*)firstImage withImage:(UIImage*)secondImage {
    CGImageRef firstImageRef = firstImage.CGImage;
    CGFloat firstWidth = CGImageGetWidth(firstImageRef);
    CGFloat firstHeight = CGImageGetHeight(firstImageRef);
    CGImageRef secondImageRef = secondImage.CGImage;
    CGFloat secondWidth = CGImageGetWidth(secondImageRef);
    CGFloat secondHeight = CGImageGetHeight(secondImageRef);
    CGSize mergedSize = CGSizeMake(MAX(firstWidth, secondWidth), MAX(firstHeight, secondHeight));
    UIGraphicsBeginImageContext(mergedSize);
    [firstImage drawInRect:CGRectMake(0, 0, firstWidth, firstHeight)];
    [secondImage drawInRect:CGRectMake(0, 0, secondWidth, secondHeight)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

73父叙、根據(jù)bundle中的圖片名創(chuàng)建imageview

+ (id)imageViewWithImageNamed:(NSString*)imageName
{
    return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}

74神郊、為imageView添加倒影

    CGRect frame = self.frame;
    frame.origin.y += (frame.size.height + 1);

    UIImageView *reflectionImageView = [[UIImageView alloc] initWithFrame:frame];
    self.clipsToBounds = TRUE;
    reflectionImageView.contentMode = self.contentMode;
    [reflectionImageView setImage:self.image];
    reflectionImageView.transform = CGAffineTransformMakeScale(1.0, -1.0);

    CALayer *reflectionLayer = [reflectionImageView layer];

    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.bounds = reflectionLayer.bounds;
    gradientLayer.position = CGPointMake(reflectionLayer.bounds.size.width / 2, reflectionLayer.bounds.size.height * 0.5);
    gradientLayer.colors = [NSArray arrayWithObjects:
                            (id)[[UIColor clearColor] CGColor],
                            (id)[[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:0.3] CGColor], nil];

    gradientLayer.startPoint = CGPointMake(0.5,0.5);
    gradientLayer.endPoint = CGPointMake(0.5,1.0);
    reflectionLayer.mask = gradientLayer;

    [self.superview addSubview:reflectionImageView];

75、畫水印

// 畫水印
- (void) setImage:(UIImage *)image withWaterMark:(UIImage *)mark inRect:(CGRect)rect
{
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 4.0)
    {
        UIGraphicsBeginImageContextWithOptions(self.frame.size, NO, 0.0);
    }
    //原圖
    [image drawInRect:self.bounds];
    //水印圖
    [mark drawInRect:rect];
    UIImage *newPic = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    self.image = newPic;
}

76趾唱、讓label的文字內(nèi)容顯示在左上／右上／左下／右下／中心頂／中心底部

自定義UILabel
// 重寫label的textRectForBounds方法
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
    CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
    switch (self.textAlignmentType) {
        case WZBTextAlignmentTypeLeftTop: {
            rect.origin = bounds.origin;
        }
            break;
        case WZBTextAlignmentTypeRightTop: {
            rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);
        }
            break;
        case WZBTextAlignmentTypeLeftBottom: {
            rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeRightBottom: {
            rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeTopCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);
        }
            break;
        case WZBTextAlignmentTypeBottomCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeLeft: {
            rect.origin = CGPointMake(0, rect.origin.y);
        }
            break;
        case WZBTextAlignmentTypeRight: {
            rect.origin = CGPointMake(rect.origin.x, 0);
        }
            break;
        case WZBTextAlignmentTypeCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);
        }
            break;

        default:
            break;
    }
    return rect;
}
- (void)drawTextInRect:(CGRect)rect {
    CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];
    [super drawTextInRect:textRect];
}

77涌乳、scrollView上的輸入框，鍵盤擋住的問題

推薦用IQKeyboardManager這個(gè)框架甜癞！
手動(dòng)解決如下
1夕晓、監(jiān)聽鍵盤彈出／消失的通知
2、在通知中加入代碼：
NSDictionary* info = [aNotification userInfo];
CGRect keyPadFrame=[[UIApplication sharedApplication].keyWindow convertRect:[[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue] fromView:self.view];
CGSize kbSize =keyPadFrame.size;
CGRect activeRect=[self.view convertRect:activeField.frame fromView:activeField.superview];
CGRect aRect = self.view.bounds;
aRect.size.height -= (kbSize.height);

CGPoint origin =  activeRect.origin;
origin.y -= backScrollView.contentOffset.y;
if (!CGRectContainsPoint(aRect, origin)) {
    CGPoint scrollPoint = CGPointMake(0.0,CGRectGetMaxY(activeRect)-(aRect.size.height));
    [backScrollView setContentOffset:scrollPoint animated:YES];
}

78悠咱、frame布局的cell動(dòng)態(tài)高度

這種通常在你的模型中添加一個(gè)輔助屬性cellHeight蒸辆，在模型中重寫這個(gè)屬性的get方法，根據(jù)你的布局和模型中的其他屬性值計(jì)算出總高度析既。最后在tableView：heightForRow方法中躬贡，根據(jù)indexPath找出對(duì)應(yīng)的模型，返回這個(gè)高度即可眼坏。

79逗宜、AutoLayout布局的cell動(dòng)態(tài)高度

// 1、設(shè)置tableView的屬性
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0; // 這個(gè)屬性非0空骚，估計(jì)cell高度

// 2纺讲、至上而下設(shè)置cell的約束，注意囤屹，上下左右最好都要頂?shù)絚ell的四周

image

80熬甚、使用performSelector:調(diào)用函數(shù)，內(nèi)存泄漏問題

當(dāng)我們?cè)陂_發(fā)中使用[obj performSelector:NSSelectorFromString(@"aMethod")];這類方法時(shí)可能會(huì)收到一個(gè)警告"performSelector may cause a leak because its selector is unknown".
是因?yàn)榫幾g器不清楚這個(gè)對(duì)象能不能相應(yīng)這個(gè)方法肋坚，如果不能乡括，則是不安全的肃廓，而且編譯器也不清楚該怎么處理這個(gè)方法的返回值！

使用以下代碼調(diào)用即可：
if (! obj) { return; }
SEL selector = NSSelectorFromString(@"aMethod");
IMP imp = [obj methodForSelector:selector];
void (*func)(id, SEL) = (void *)imp;
func(obj, selector);

或者：
SEL selector = NSSelectorFromString(@"aMethod");
((void (*)(id, SEL))[obj methodForSelector:selector])(obj, selector);

81诲泌、一個(gè)字符串是否包含另一個(gè)字符串

// 方法1
if ([str1 containsString:str2]) {
        NSLog(@"str1包含str2");
    } else {
        NSLog(@"str1不包含str2");
    }

// 方法2
if ([str1 rangeOfString: str2].location == NSNotFound) {
        NSLog(@"str1不包含str2");
    } else {
        NSLog(@"str1包含str2");
    }

82盲赊、cell去除選中效果

cell.selectionStyle = UITableViewCellSelectionStyleNone;

83、cell點(diǎn)按效果

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

84敷扫、當(dāng)刪除一個(gè)從xib拖出來的屬性時(shí)哀蘑，一定記得把xib中對(duì)應(yīng)的線也刪掉，不然會(huì)報(bào)類似[<ViewController 0x7fea6ed05980> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key的crash

image

85葵第、真機(jī)測(cè)試的時(shí)候報(bào)錯(cuò)：Could not launch "你的 App"绘迁，process launch failed: Security

因?yàn)槟愕腶pp沒有上線，iOS9開始卒密，需要手動(dòng)信任Xcode生成的描述文件缀台，打開手機(jī)設(shè)置->通用->描述文件->點(diǎn)擊你的app的描述文件->點(diǎn)擊信任

86、真機(jī)測(cè)試的時(shí)候報(bào)錯(cuò)：Could not find Developer Disk Image

這是因?yàn)槟愕脑O(shè)備系統(tǒng)版本大于Xcode能兼容的系統(tǒng)版本哮奇，比如你的設(shè)備是iOS10.3膛腐，而Xcode版本是8.2（Xcode8.2最大兼容iOS10.2），就會(huì)報(bào)這個(gè)錯(cuò)誤鼎俘。解決辦法就是升級(jí)Xcode哲身！

87、UITextView沒有placeholder的問題而芥？

網(wǎng)上有很多此類自定義控件，也可以參考下我寫的一個(gè)UITextView分類 UITextView-WZB

88膀值、移除字符串中的空格和換行

+ (NSString *)removeSpaceAndNewline:(NSString *)str {
    NSString *temp = [str stringByReplacingOccurrencesOfString:@" " withString:@""];
    temp = [temp stringByReplacingOccurrencesOfString:@"\r" withString:@""];
    temp = [temp stringByReplacingOccurrencesOfString:@"\n" withString:@""];
    return temp;
}

89棍丐、判斷字符串中是否有空格

+ (BOOL)isBlank:(NSString *)str {
    NSRange _range = [str rangeOfString:@" "];
    if (_range.location != NSNotFound) {
        //有空格
        return YES;
    } else {
        //沒有空格
        return NO;
    }
}

90、獲取一個(gè)視頻的第一幀圖片

    NSURL *url = [NSURL URLWithString:filepath];
    AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:url options:nil];
    AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];
    generate1.appliesPreferredTrackTransform = YES;
    NSError *err = NULL;
    CMTime time = CMTimeMake(1, 2);
    CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];
    UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];

    return one;

91沧踏、獲取視頻的時(shí)長(zhǎng)

+ (NSInteger)getVideoTimeByUrlString:(NSString *)urlString {
    NSURL *videoUrl = [NSURL URLWithString:urlString];
    AVURLAsset *avUrl = [AVURLAsset assetWithURL:videoUrl];
    CMTime time = [avUrl duration];
    int seconds = ceil(time.value/time.timescale);
    return seconds;
}

92歌逢、字符串是否為空

+ (BOOL)isEqualToNil:(NSString *)str {
    return str.length <= 0 || [str isEqualToString:@""] || !str;
}

93、將app上傳到App Store的時(shí)候通常會(huì)遇到這個(gè)問題

image

很多人說這事蘋果爸爸服務(wù)器問題翘狱，重復(fù)嘗試幾次秘案，總會(huì)成功的！
但是經(jīng)過嘗試發(fā)現(xiàn)如果使用Application Loader上傳成功率就非常高潦匈，所以還是推薦把ipa文件導(dǎo)出直接用Application Loader上傳阱高。
如果Application Loader也不行，需要檢查下自己的網(wǎng)絡(luò)茬缩，有時(shí)候vpn也會(huì)提高速度赤惊。

94、當(dāng)tableView占不滿一屏?xí)r凰锡，去除下邊多余的單元格

self.tableView.tableHeaderView = [UIView new];
self.tableView.tableFooterView = [UIView new];

95、isKindOfClass和isMemberOfClass的區(qū)別

isKindOfClass可以判斷某個(gè)對(duì)象是否屬于某個(gè)類奄容，或者這個(gè)類的子類壮韭。
isMemberOfClass更加精準(zhǔn)，它只能判斷這個(gè)對(duì)象類型是否為這個(gè)類(不能判斷子類)

96员串、__block

當(dāng)一個(gè)局部變量需要在block里改變時(shí)，需要在定義時(shí)加上__block修飾昼扛，具體請(qǐng)看官方文檔 http://developer.apple.com/library/ios/documentation/cocoa/Conceptual/Blocks/Articles/bxVariables.html#//apple_ref/doc/uid/TP40007502-CH6-SW6

97寸齐、-[ViewController aMethod:]: unrecognized selector sent to instance 0x7fe91e607fb0

這是一個(gè)經(jīng)典錯(cuò)誤，ViewController不能響應(yīng)aMethod這個(gè)方法野揪，錯(cuò)誤原因可能viewController文件中沒有實(shí)現(xiàn)aMethod這個(gè)方法

98访忿、UITableView (<UITableView: 0x7ff19b027000; >) failed to obtain a cell from its dataSource (<ViewController: 0x7ff19a507520>)

這個(gè)錯(cuò)誤原因是tableView的代理方法-tableView:cellForRowAtIndexPath:需要返回一個(gè)UITableViewCell,而你返回了一個(gè)nil。另外這個(gè)地方返回值不是UITableViewCell類型也會(huì)導(dǎo)致崩潰

99斯稳、約束如何做UIView動(dòng)畫海铆？

1、把需要改的約束Constraint拖條線出來挣惰，成為屬性
2卧斟、在需要?jiǎng)赢嫷牡胤郊尤氪a，改變此屬性的constant屬性
3憎茂、開始做UIView動(dòng)畫珍语，動(dòng)畫里邊調(diào)用layoutIfNeeded方法

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *buttonTopConstraint;
self.buttonTopConstraint.constant = 100;
    [UIView animateWithDuration:.5 animations:^{
        [self.view layoutIfNeeded];
    }];

100、從NSURL中拿到鏈接字符串

NSString *urlString = myURL.absoluteString;

101竖幔、將tableView滾動(dòng)到頂部

[tableView setContentOffset:CGPointZero animated:YES];
或者
[tableView scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:YES];

102板乙、如果用addTarget:action:forControlEvents:方法為一個(gè)button添加了很多點(diǎn)擊事件，在某個(gè)時(shí)刻想一次刪除怎么辦拳氢？只需要調(diào)用下邊這句代碼

[youButton removeTarget:nil action:nil forControlEvents:UIControlEventAllEvents];

103募逞、某個(gè)字體的高度

font.lineHeight;

104、刪除某個(gè)view所有的子視圖

[[someView subviews]
 makeObjectsPerformSelector:@selector(removeFromSuperview)];

105馋评、刪除NSUserDefaults所有記錄

//方法一
  NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];
 [[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];   
 //方法二  
- (void)resetDefaults {   
  NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];
     NSDictionary * dict = [defs dictionaryRepresentation];
     for (id key in dict) {
          [defs removeObjectForKey:key];
     }
      [defs synchronize];
 }
// 方法三
[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];

106放接、禁用系統(tǒng)滑動(dòng)返回功能

- (void)viewDidAppear:(BOOL)animated
{
     [super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
    }
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
    }
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
     return NO;
}

107、模擬器報(bào)錯(cuò)

image

解決辦法：
打開模擬器->Simulator->Reset Content and Settings...
如果不行留特，就重啟試試纠脾！

108、自定義cell選中背景顏色

UIView *bgColorView = [[UIView alloc] init];
bgColorView.backgroundColor = [UIColor redColor];
[cell setSelectedBackgroundView:bgColorView];

109蜕青、UILabel設(shè)置內(nèi)邊距

子類化UILabel苟蹈，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {
    // 邊距，上左下右
    UIEdgeInsets insets = {0, 5, 0, 5};
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

110右核、UILabel設(shè)置文字描邊

子類化UILabel汉操，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect
{
    CGContextRef c = UIGraphicsGetCurrentContext();
    // 設(shè)置描邊寬度
    CGContextSetLineWidth(c, 1);
    CGContextSetLineJoin(c, kCGLineJoinRound);
    CGContextSetTextDrawingMode(c, kCGTextStroke);
    // 描邊顏色
    self.textColor = [UIColor redColor];
    [super drawTextInRect:rect];
    // 文本顏色
    self.textColor = [UIColor yellowColor];
    CGContextSetTextDrawingMode(c, kCGTextFill);
    [super drawTextInRect:rect];
}

111、使用模擬器截圖

快捷鍵command + s
或者File->Save Screen Shot

112蒙兰、scrollView滾動(dòng)到最下邊

CGPoint bottomOffset = CGPointMake(0, scrollView.contentSize.height - scrollView.bounds.size.height);
[scrollView setContentOffset:bottomOffset animated:YES];

113磷瘤、UIView背景顏色漸變

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 100)];
    [self.view addSubview:view];
    CAGradientLayer *gradient = [CAGradientLayer layer];
    gradient.frame = view.bounds;
    gradient.colors = [NSArray arrayWithObjects:(id)[[UIColor blackColor] CGColor], (id)[[UIColor whiteColor] CGColor], nil];
    [view.layer insertSublayer:gradient atIndex:0];

114芒篷、停止UIView動(dòng)畫

[yourView.layer removeAllAnimations]

115、為UIView某個(gè)角添加圓角

// 左上角和右下角添加圓角
UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:view.bounds byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomRight) cornerRadii:CGSizeMake(20, 20)];
    CAShapeLayer *maskLayer = [CAShapeLayer layer];
    maskLayer.frame = view.bounds;
    maskLayer.path = maskPath.CGPath;
    view.layer.mask = maskLayer;

116采缚、刪除Xcode Derived data緩存數(shù)據(jù)

依次點(diǎn)擊Xcode -> Preferences -> location针炉，然后點(diǎn)擊 Derived data路徑后到小箭頭，刪除這個(gè)文件夾下的數(shù)據(jù)就可以了扳抽，如圖

image

117篡帕、將一個(gè)view放置在其兄弟視圖的最上面

[parentView bringSubviewToFront:yourView]

118、將一個(gè)view放置在其兄弟視圖的最下面

[parentView sendSubviewToBack:yourView]

119贸呢、讓手機(jī)震動(dòng)一下

倒入框架
#import <AudioToolbox/AudioToolbox.h>
AudioServicesPlayAlertSound(kSystemSoundID_Vibrate);
或者
AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);

120镰烧、layoutSubviews方法什么時(shí)候調(diào)用？

1楞陷、init方法不會(huì)調(diào)用
2怔鳖、addSubview方法等時(shí)候會(huì)調(diào)用
3、bounds改變的時(shí)候調(diào)用
4固蛾、scrollView滾動(dòng)的時(shí)候會(huì)調(diào)用scrollView的layoutSubviews方法(所以不建議在scrollView的layoutSubviews方法中做復(fù)雜邏輯)
5结执、旋轉(zhuǎn)設(shè)備的時(shí)候調(diào)用
6、子視圖被移除的時(shí)候調(diào)用
參考請(qǐng)看：http://blog.logichigh.com/2011/03/16/when-does-layoutsubviews-get-called/

121艾凯、讓UILabel在指定的地方換行

// 換行符為\n,在需要換行的地方加上這個(gè)符號(hào)即可献幔，如 
label.numberOfLines = 0;
label.text = @"此處\n換行";

122、搖一搖功能

1趾诗、打開搖一搖功能
    [UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;
2蜡感、讓需要搖動(dòng)的控制器成為第一響應(yīng)者
[self becomeFirstResponder];
3、實(shí)現(xiàn)以下方法

// 開始搖動(dòng)
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 取消搖動(dòng)
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 搖動(dòng)結(jié)束
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event

123恃泪、獲取圖片大小

CGFloat imageWidth = image.size.width;
    CGFloat imageHeight = imageWidth * image.scale;

124郑兴、獲取view的坐標(biāo)在整個(gè)window上的位置

// v上的(0, 0)點(diǎn)在toView上的位置
CGPoint point = [v convertPoint:CGPointMake(0, 0) toView:[UIApplication sharedApplication].windows.lastObject];
或者
CGPoint point = [v.superview convertPoint:v.frame.origin toView:[UIApplication sharedApplication].windows.lastObject];

125、提交App Store審核程序限制

您的應(yīng)用程序的未壓縮大小必須小于4GB悟泵。每個(gè)Mach-O可執(zhí)行文件（例如app_name.app/app_name）不能超過這些限制：
對(duì)于MinimumOSVersion小于7.0的應(yīng)用程序：__TEXT二進(jìn)制文件中所有部分的總數(shù)最多為80 MB 杈笔。

對(duì)于MinimumOSVersion7.x到8.x的應(yīng)用程序：__TEXT對(duì)于二進(jìn)制文件中每個(gè)體系結(jié)構(gòu)片段的每個(gè)片段闪水，最大為60 MB 糕非。
對(duì)于MinimumOSVersion9.0或更高版本的應(yīng)用程序：__TEXT二進(jìn)制文件中所有部分的總數(shù)最多為500 MB 。參閱：iTunes Connect開發(fā)者指南

126球榆、修改UISegmentedControl的字體大小

[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15.0f]} forState:UIControlStateNormal];

127朽肥、在非ViewController的地方彈出UIAlertController對(duì)話框

//  最好抽成一個(gè)分類
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"message" preferredStyle:UIAlertControllerStyleAlert];
//...
id rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
if([rootViewController isKindOfClass:[UINavigationController class]])
{
    rootViewController = ((UINavigationController *)rootViewController).viewControllers.firstObject;
}
if([rootViewController isKindOfClass:[UITabBarController class]])
{
    rootViewController = ((UITabBarController *)rootViewController).selectedViewController;
}
[rootViewController presentViewController:alertController animated:YES completion:nil];

128、獲取一個(gè)view所屬的控制器

// view分類方法
- (UIViewController *)belongViewController {
    for (UIView *next = [self superview]; next; next = next.superview) {
        UIResponder* nextResponder = [next nextResponder];
        if ([nextResponder isKindOfClass:[UIViewController class]]) {
            return (UIViewController *)nextResponder;
        }
    }
    return nil;
}

129持钉、UIImage和base64互轉(zhuǎn)

// view分類方法
- (NSString *)encodeToBase64String:(UIImage *)image {
 return [UIImagePNGRepresentation(image) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}

- (UIImage *)decodeBase64ToImage:(NSString *)strEncodeData {
  NSData *data = [[NSData alloc]initWithBase64EncodedString:strEncodeData options:NSDataBase64DecodingIgnoreUnknownCharacters];
  return [UIImage imageWithData:data];
}

130衡招、UIWebView設(shè)置背景透明

[webView setBackgroundColor:[UIColor clearColor]];
[webView setOpaque:NO];

131、判斷NSDate是不是今天

NSDateComponents *otherDay = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:aDate];
NSDateComponents *today = [[NSCalendar currentCalendar] components:NSCalendarUnitEra | NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay fromDate:[NSDate date]];
if([today day] == [otherDay day] &&
   [today month] == [otherDay month] &&
   [today year] == [otherDay year] &&
   [today era] == [otherDay era]) {
    // 是今天
}

132每强、設(shè)置tableView分割線顏色

[self.tableView setSeparatorColor:[UIColor myColor]];

133始腾、設(shè)置屏幕方向

 NSNumber *orientationTarget = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
[[UIDevice currentDevice] setValue:orientationTarget forKey:@"orientation"];
[UIViewController attemptRotationToDeviceOrientation];

134州刽、比較兩個(gè)顏色是否相等

- (BOOL)isEqualToColor:(UIColor *)otherColor {
    CGColorSpaceRef colorSpaceRGB = CGColorSpaceCreateDeviceRGB();

    UIColor *(^convertColorToRGBSpace)(UIColor*) = ^(UIColor *color) {
        if (CGColorSpaceGetModel(CGColorGetColorSpace(color.CGColor)) == kCGColorSpaceModelMonochrome) {
            const CGFloat *oldComponents = CGColorGetComponents(color.CGColor);
            CGFloat components[4] = {oldComponents[0], oldComponents[0], oldComponents[0], oldComponents[1]};
            CGColorRef colorRef = CGColorCreate( colorSpaceRGB, components );

            UIColor *color = [UIColor colorWithCGColor:colorRef];
            CGColorRelease(colorRef);
            return color;            
        } else
            return color;
    };

    UIColor *selfColor = convertColorToRGBSpace(self);
    otherColor = convertColorToRGBSpace(otherColor);
    CGColorSpaceRelease(colorSpaceRGB);

    return [selfColor isEqual:otherColor];
}

135、tableViewCell分割線頂?shù)筋^

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    [cell setSeparatorInset:UIEdgeInsetsZero];
    [cell setLayoutMargins:UIEdgeInsetsZero];
    cell.preservesSuperviewLayoutMargins = NO;
}

- (void)viewDidLayoutSubviews {
    [self.tableView setSeparatorInset:UIEdgeInsetsZero];
    [self.tableView setLayoutMargins:UIEdgeInsetsZero];
}

136浪箭、不讓控制器的view隨著控制器的xib拉伸或壓縮

self.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

137穗椅、cocoaPods報(bào)錯(cuò) : [!] Unable to add a source with url https://github.com/CocoaPods/Specs.git named master-1.

You can try adding it manually in ~/.cocoapods/repos or via pod repo add.

解決方法：這是因?yàn)殡娔X里安裝了另外一個(gè)Xcode導(dǎo)致cocoapods找不到路徑了
在終端執(zhí)行 sudo xcode-select -switch /Applications/Xcode.app 即可

138、安裝cocoapods的時(shí)候出現(xiàn) ERROR: While executing gem ... (Errno::EPERM)

Operation not permitted - /usr/bin/pod

解決辦法：直接在終端執(zhí)行 sudo gem install -n /usr/local/bin cocoapods

139奶栖、在狀態(tài)欄增加網(wǎng)絡(luò)請(qǐng)求的菊花匹表，類似safari加載網(wǎng)頁(yè)的時(shí)候狀態(tài)欄菊花

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

140、檢查一個(gè)rect是否包含一個(gè)point

// point是否在rect內(nèi)
BOOL isContains = CGRectContainsPoint(rect, point);

141宣鄙、在指定的寬度下袍镀，讓UILabel自動(dòng)設(shè)置最佳font

label.adjustsFontSizeToFitWidth = YES;

142、將一個(gè)image保存在相冊(cè)中

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

或者
#import <Photos/Photos.h>
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        PHAssetChangeRequest *changeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
        changeRequest.creationDate          = [NSDate date];
    } completionHandler:^(BOOL success, NSError *error) {
        if (success) {
            NSLog(@"successfully saved");
        }
        else {
            NSLog(@"error saving to photos: %@", error);
        }
    }];

143冻晤、修改cell.imageView的大小

UIImage *icon = [UIImage imageNamed:@""];
CGSize itemSize = CGSizeMake(30, 30);
UIGraphicsBeginImageContextWithOptions(itemSize, NO ,0.0);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[icon drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

144苇羡、為一個(gè)view添加虛線邊框

 CAShapeLayer *border = [CAShapeLayer layer];
    border.strokeColor = [UIColor colorWithRed:67/255.0f green:37/255.0f blue:83/255.0f alpha:1].CGColor;
    border.fillColor = nil;
    border.lineDashPattern = @[@4, @2];
    border.path = [UIBezierPath bezierPathWithRect:view.bounds].CGPath;
    border.frame = view.bounds;
    [view.layer addSublayer:border];

145、UITextView中打開或禁用復(fù)制明也，剪切宣虾，選擇，全選等功能

// 繼承UITextView重寫這個(gè)方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
// 返回NO為禁用温数，YES為開啟
    // 粘貼
    if (action == @selector(paste:)) return NO;
    // 剪切
    if (action == @selector(cut:)) return NO;
    // 復(fù)制
    if (action == @selector(copy:)) return NO;
    // 選擇
    if (action == @selector(select:)) return NO;
    // 選中全部
    if (action == @selector(selectAll:)) return NO;
    // 刪除
    if (action == @selector(delete:)) return NO;
    // 分享
    if (action == @selector(share)) return NO;
    return [super canPerformAction:action withSender:sender];
}

作者：雜霧無塵
鏈接：http://www.reibang.com/p/1ff9e44ccc78
來源：簡(jiǎn)書
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