iOS自動布局

iOS自動布局

一開始用VFL語言都是這樣實現自動布局的，一兩個控制項還好，多幾個控制項簡直不能忍。

    _backgroundImageView = [[UIImageView alloc] init];    _backgroundImageView.backgroundColor = [UIColor clearColor];    _backgroundImageView.translatesAutoresizingMaskIntoConstraints = NO;    [self addSubview:_backgroundImageView];        NSMutableArray* contraints = [NSMutableArray new];    [contraints addObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[_backgroundImageView]-0-|"                                                                            options:0 metrics:nil                                                                              views:NSDictionaryOfVariableBindings(_backgroundImageView)]];    [contraints addObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-0-[_backgroundImageView]-0-|"                                                                            options:0                                                                            metrics:nil                                                                              views:NSDictionaryOfVariableBindings(_backgroundImageView)]];    [self addConstraints:contraints];

後來發現了Masonry 現在都是這樣實現自動布局的：

    _scrollView = [[UIScrollView alloc] init];    _scrollView.pagingEnabled = YES;    _scrollView.backgroundColor = [UIColor clearColor];    [self addSubview:_scrollView];    [_scrollView makeConstraints:^(MASConstraintMaker *make) {        make.left.equalTo(0);        make.right.equalTo(0);        make.top.equalTo(0);        make.bottom.equalTo(0);    }];