持續(xù)更新有勾。
1望伦、獲取應(yīng)用安裝時(shí)間
NSURL *docURL = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
NSError *error;
NSDictionary *dict = [[NSFileManager defaultManager] attributesOfItemAtPath:docURL.path error:&error];
NSDate *creationDate = [dict objectForKey:NSFileCreationDate];
NSLog(@"應(yīng)用安裝時(shí)間: %@", creationDate);
2林说、null 打印出是尖括號(hào)<null>，nil 是圓括號(hào)(null)
NSLog(@"%@--%@", [NSNull null], nil);
打印出：<null>--(null)
3屯伞、子view繼承父view的手勢腿箩，如果不想這樣，可以通過手勢代理做個(gè)判斷：
1. 遵守協(xié)議<UIGestureRecognizerDelegate>
2. 設(shè)置手勢的代理：singleTap.delegate = self;
3. 處理手勢代理
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
//如果是子視圖的話愕掏，返回NO度秘，表示不要接收touch
// if ([touch.view isDescendantOfView:self.redView]) {
// return NO;
// }
if (touch.view == self.redView) {
return NO;
}
return YES;
}
4、簡單的Masonry動(dòng)畫
如果約束還沒有生成的時(shí)候需要?jiǎng)赢嫸牛枰日{(diào)用[superview layoutIfNeeded]剑梳，其作用是如果有需要刷新的標(biāo)記，立即調(diào)用layoutSubviews進(jìn)行布局滑潘；如果沒有標(biāo)記垢乙，不會(huì)調(diào)用layoutSubviews。
示例
//如果不能保證做動(dòng)畫前布局已經(jīng)完成语卤，可以手動(dòng)調(diào)用一下
[self.backgroundView layoutIfNeeded];
[UIView animateWithDuration:0.4 animations:^{
[self.containerView mas_updateConstraints:^(MASConstraintMaker *make) {
make.bottom.equalTo(@0);
}];
//self.containerView的父視圖是self.backgroundView
[self.backgroundView layoutIfNeeded];
}];
5追逮、 tableView可以設(shè)置部分section高度自適應(yīng)，部分手動(dòng)指定高度
1. 國際慣例
_mTableView.estimatedRowHeight = 100;
_mTableView.rowHeight = UITableViewAutomaticDimension;
2. 代理里指定高度
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.section == 0) {
return UITableViewAutomaticDimension;
} else {
return 45;
}
}
6粹舵、 @encode()返回一個(gè)給定的Objective-C 類型編碼
NSLog(@"\nchar = %s, short = %s, int = %s, NSInteger = %s,\nchar * = %s, BOOL = %s, SEL = %s, NSObject * = %s,\nCGFloat = %s, double = %s, long long = %s, long = %s,\nid = %s",
@encode(char), @encode(short), @encode(int), @encode(NSInteger),
@encode(char *), @encode(BOOL), @encode(SEL), @encode(NSObject *),
@encode(CGFloat), @encode(double), @encode(long long), @encode(long),
@encode(id));
char = c, short = s, int = i, NSInteger = q,
char * = *, BOOL = B, SEL = :, NSObject * = @,
CGFloat = d, double = d, long long = q, long = q,
id = @
7钮孵、NSUserDefaults
- 可變數(shù)組
通過mutableArrayValueForKey:取值。
- 可變數(shù)組
-
- 通過
initWithSuiteName:單獨(dú)創(chuàng)建一個(gè)plist文件
NSUserDefaults *lynn = [[NSUserDefaults alloc] initWithSuiteName:@"LynnZhang"]; [lynn setValue:@{@"name": @"LynnZhang", @"age": @18} forKey:@"userinfo"]; [lynn synchronize]; - 通過
8眼滤、內(nèi)存對(duì)其
typedef struct {
char Char;//0-1
short Short;//2-3
double Double;//8-15
int Int;//16-20
} Stu_one;//24
typedef struct {
char Char;//0-1
short Short;//2-3
int Int;//4-7
double Double;//8-15
} Stu_two;//16
其他
- 蘋果開放源碼：https://opensource.apple.com/tarballs向胡，對(duì)于iOS開發(fā)者來說务蝠，一般要看一下objc薪缆。
- GNUstep開源的"Foundation源碼"
