iOS開發(fā)小Tips

1.AFNetworking返回結(jié)果默認(rèn)回到主線程中惹恃，所以在AFNetworking的返回結(jié)果block中無需手動回歸主線程。

2.delegate盡量使用weak修飾,弱引用

3.block中的代碼不需要特別回歸注線程棺牧，設(shè)置block時在哪個線程座舍，block中的代碼就執(zhí)行在哪個線程

4.使用NSObject+MJKeyValue進(jìn)行模型轉(zhuǎn)換時，int類型可直接轉(zhuǎn)為string類型陨帆，原因不明曲秉，但可以正確的轉(zhuǎn)換過來

小技巧

新項目http不可使用
在info.plist 中加入NSAppTransportSecurity（NSDictionary）以及 NSAllowsArbitraryLoads（Bool）并設(shè)置為YES

delegate盡量使用weak修飾,弱引用

block中的代碼不需要特別回歸注線程，設(shè)置block時在哪個線程疲牵，block中的代碼就執(zhí)行在哪個線程

使用 MJExtension 進(jìn)行字典轉(zhuǎn)模型時時承二，如果模型對應(yīng)屬性為NSString
那么原始字典中對應(yīng)的鍵值對的value的類型是int或NSNumber類型
MJExtension內(nèi)部做了轉(zhuǎn)換操作。

基類常用Tips

//字符串截取纲爸，從第4個字符開始截取到末尾亥鸠，包含第4個字符
[a substringFromIndex:4];
//字符串截取，從開始截取到第4個字符识啦，不包含第4個字符
[a substringToIndex:4];
//字符串截取负蚊，從第1個字符，往后截2個字符長度
[a substringWithRange:NSMakeRange(1,2)] 

//NSString轉(zhuǎn)NSArry
NSArray *array = [@"1,2,3,4,5" componentsSeparatedByString:@","];

//NSArry轉(zhuǎn)NSString
NSString *str = [@[@"1", @"2", @"3"] componentsJoinedByString:@","];

//判斷代理是否有接收者
if ([self.delegate respondsToSelector:@selector(callBack:)]) {

}

//異步線程切換主線程
dispatch_async(dispatch_get_main_queue(), ^{
    //do something
});

//延時執(zhí)行某一步驟
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC));
    
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
  [self.webView performSelector:@selector(loadRequest:) withObject:[NSURLRequest requestWithURL:[NSURL fileURLWithPath:path]]];
});

電量欄導(dǎo)航欄相關(guān)

//電量欄文字改為白色顏色
// Info.plist 中 View controller-based status bar appearance設(shè)置為NO
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
//設(shè)置全局NavgationBar背景圖片
[[UINavigationBar appearance] setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
//設(shè)置全局NavgationBar背景顏色
[[UINavigationBar appearance] setBarTintColor:[UIColor blueColor]];
//設(shè)置全局NavgationBar左右按鈕顏色
[[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];
//設(shè)置全局NavgationBar標(biāo)題顏色
[[UINavigationBar appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];

//Navgation造成的位置偏移或遮擋(64像素問題)
if ([self respondsToSelector:@selector(setEdgesForExtendedLayout:)]){
   self.edgesForExtendedLayout = UIRectEdgeNone;
}

//隱藏單個頁面的返回按鈕
self.navigationItem.hidesBackButton = YES;

//導(dǎo)航欄背景透明
[self.navigationController.navigationBar setBackgroundImage:[UIImage new] forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = [UIImage new];
//背景恢復(fù)原色
[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.shadowImage = nil;

//Navgation完全隱藏
- (void)viewDidLoad {
    [super viewDidLoad];
    self.navigationController.delegate = self;
}

-(void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [self.navigationController setNavigationBarHidden:YES animated:YES];
}

//Navgation在下一頁面再顯示
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    
    if (viewController != self && [navigationController isNavigationBarHidden]) {
        [navigationController setNavigationBarHidden:NO animated:animated];
    }
}

UI常用Tips

//從storyBoard中獲取UIViewController
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *viewController = [storyboard instantiateViewControllerWithIdentifier:@"UserInfoListViewController"];

//從Xib獲取UIViewController
RegistViewController *regist = [[RegistViewController alloc] initWithNibName:@"RegistViewController" bundle:nil];

//從storyBoard抽取自定義的UITableViewCell
CustCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CustomCellIdentifier"];

//UITableView刪除多余的橫線
self.tableView.tableFooterView = [[UIView alloc] init];

//UITableView的Cell自適應(yīng)
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0; 

//讓view保持在最上層
[self.view bringSubviewToFront:sonView];
//讓view保持在最下層
[self.view sendSubviewToBack:sonView];