iOS Masonry的使用

Masonry 源码：https://github.com/Masonry/Masonry

也可以使用CocoaPods直接下载Masonry

Masonry是一个轻量级的布局框架 拥有自己的描述语法 采用更优雅的链式语法封装自动布局 简洁明了 并具有高可读性 而且同时支持 iOS 和 Max OS X。

我通过3个小例子简单介绍一下Masonry的使用方法

实例1:

UIView *blackView = [[UIView alloc] init];
    blackView.backgroundColor = [UIColor blackColor];
    //使用masonry,要把视图先添加在父视图上才能再约束,不然会crash
    [self.view addSubview:blackView];

    UIView *grayView = [[UIView alloc] init];
    grayView.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:grayView];

    [blackView mas_makeConstraints:^(MASConstraintMaker *make) {
        //黑View顶边距为
        make.top.and.left.mas_equalTo();
        //黑View右边距
        make.right.mas_equalTo(-);
    }];

    [grayView mas_makeConstraints:^(MASConstraintMaker *make) {
        //灰View的右边距和底边距为
        make.right.and.bottom.mas_equalTo(-);
        //灰View高度 == 黑View
        make.height.equalTo(blackView);
        //添加上边距约束 (上边距==黑色View的下边框 + 偏移量)
        make.top.equalTo(blackView.mas_bottom).offset();
        //添加左边距 (左边距 == 父视图纵轴中心 + 偏移量)
        make.left.equalTo(self.view.mas_centerX).offset();
    }];
           

实例2:

UIView *aView = [[UIView alloc] init];
    aView.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:aView];

    [aView mas_makeConstraints:^(MASConstraintMaker *make) {
        //aView的size
        make.size.mas_equalTo(CGSizeMake(, ));
        //aView的左边距和顶边距为
        make.left.and.top.mas_equalTo();

    }];

    UIView *bView = [[UIView alloc] init];
    bView.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:bView];

    [bView mas_makeConstraints:^(MASConstraintMaker *make) {
        //bView的size和top与aView的设置一样
        make.size.and.top.mas_equalTo(aView);
        //bView右边距
        make.right.mas_equalTo(-);
    }];

    UIView *cView = [[UIView alloc] init];
    cView.backgroundColor = [UIColor redColor];
    [self.view addSubview:cView];

    [cView mas_makeConstraints:^(MASConstraintMaker *make) {
        //cView左边和aView的右边距离为
        make.left.equalTo(aView.mas_right).offset();
        //cView右边和bView的左边距离为
        make.right.equalTo(bView.mas_left).offset();
        make.top.mas_equalTo();
        make.height.mas_equalTo();
    }];
           

实例3:

UIView *aView = [[UIView alloc] init];
    aView.backgroundColor = [UIColor redColor];
    [self.view addSubview:aView];

    _bView = [[UIView alloc] init];
    _bView.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:_bView];

    UIView *cView = [[UIView alloc] init];
    cView.backgroundColor = [UIColor blueColor];
    [self.view addSubview:cView];

    [aView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(self.view.mas_left).offset();
        make.bottom.equalTo(self.view.mas_bottom).offset(-);
        //self.view宽度的倍
        make.width.equalTo(self.view.mas_width).multipliedBy();
        //self.view高度的倍
        make.height.equalTo(self.view.mas_height).multipliedBy();
    }];

    [_bView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(aView.mas_right).offset();
        make.width.equalTo(aView.mas_width);
        make.height.equalTo(aView.mas_height);
        make.bottom.equalTo(self.view.mas_bottom).offset(-);
    }];

    [cView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(_bView.mas_right).offset();
        make.bottom.equalTo(aView.mas_bottom);
        make.width.equalTo(aView.mas_width);
        make.height.equalTo(aView.mas_height);
        //priority优先级 : 数值越高越优先,默认值为
        make.left.equalTo(aView.mas_right).offset().priority();
    }];

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(TapAction)];
    [_bView addGestureRecognizer:tap];
           

- (void)TapAction{
    //删除bView
    //cView的约束这句话开始有效果:make.left.equalTo(aView.mas_right).offset().priority();
    [self.bView removeFromSuperview];
    [UIView animateWithDuration: animations:^{
        [self.view layoutIfNeeded];
    }];
}