本文共 4842 字，大约阅读时间需要 16 分钟。
一、 UIViewAutoresizing只能控制父子视图之间的布局 首先父视图要允许子视图自动伴随父视图变化而变化 然后子视图自己设置怎么伴随变化 设置 子视图 自动布局 1.必须父视图允许子视图自动布局 2.子视图自己设置布局方式 //父视图设置父子视图自适应/停靠模式 _redView.autoresizesSubviews = YES;//允许子视图伴随父视图自动变化 //子视图设置子视图的自适应模式 blueView.autoresizingMask autolayout iOS6的时候出来的 iPhone5出来了 sizeclass iOS8的时候出来的 github 二.自动布局(多屏适配) 1.为什么使用自动布局 iphone手机的分辨率越来越多,有320*480, 640*960, 640*1136, 750*1334, 1080*1920 使用代码控制frame坐标和大小的化,会花费大量时间精力. 为了解决适配问题,苹果推出了自动布局 2.自动布局原理 通过给视图添加约束的方式,使视图在任何屏幕上都可以正常显示 autolayout 用 constraints(约束) 来控制 控件的大小和位置 auto layout 加约束条件 问题1:要么加少了 起不到作用，2.加多了产生了冲突 有可能崩溃 3.如何给视图添加约束 Xcode—>Editor—>Pin 4.有哪些约束  1).Width //设置视图固定宽度 2).Height //设置视图固定高度 3).Horizontal Spacing //同级视图之间的横向间距 4).Vertical Spacing //同级视图之间的纵向间距 5).Leading Space to SuperView //与父视图的左间距 6).Trailing Space to SuperView //与父视图的右间距 7).Top Space to SuperView //与父视图的上间距 8).Botton Space to SuperView //与父视图的下间距 9).Widths Equally //设置同级视图宽度比例 10).Height Equally //设置同级视图高度比例 NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:self.contentView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:0 multiplier:1.0 constant:1000]; NSLayoutConstraint *constraint2 = [NSLayoutConstraint constraintWithItem:self.contentView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:0 multiplier:1.0 constant:200]; [self.contentView addConstraint:constraint]; [self.contentView addConstraint:constraint2]; NSDictionary *views = NSDictionaryOfVariableBindings(_contentView); // NSDictionary *dict = @{@"_contentView": _contentView}; NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:[_contentView(1000)]" options:0 metrics:nil views:views]; NSArray *constraints2 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[_contentView(200)]" options:0 metrics:nil views:views]; [_contentView addConstraints:constraints]; [_contentView addConstraints:constraints2]; =================================================== VFL 语言添加约束 UIView *redView = [[UIView alloc] initWithFrame:CGRectZero]; redView.backgroundColor = [UIColor redColor]; // 通常都设置成NO redView.translatesAutoresizingMaskIntoConstraints = NO; [self.view addSubview:redView]; UIView *blueView = [[UIView alloc] initWithFrame:CGRectZero]; blueView.backgroundColor = [UIColor blueColor]; // 通常都设置成NO blueView.translatesAutoresizingMaskIntoConstraints = NO; [self.view addSubview:blueView]; NSDictionary *views = NSDictionaryOfVariableBindings(redView, blueView); //NSDictionary *dict = @{@“redView”:redView,@“blueView”: blueView}; NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-100-[redView(100)]" options:0 metrics:nil views:views]; [self.view addConstraints:constraints]; NSArray *constraints2 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-100-[redView(50)]" options:0 metrics:nil views:views]; [self.view addConstraints:constraints2]; NSArray *constraints3 = [NSLayoutConstraint constraintsWithVisualFormat:@"H:[redView]-50-[blueView(==redView)]" options:0 metrics:nil views:views]; [self.view addConstraints:constraints3]; NSArray *constraints4 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:[redView]-50-[blueView(==redView)]" options:0 metrics:nil views:views]; [self.view addConstraints:constraints4]; 5.用代码做自动布局 使用第三方Masonry库 [topView mas_makeConstraints:^(MASConstraintMaker *make) { make.top.equalTo(self.view.mas_top).with.offset(0); //topView上边距与self.view上边距为0 make.left.equalTo(self.view.mas_left).with.offset(0); //topView左边距与self.view左边距为0 make.right.equalTo(self.view.mas_right).with.offset(0); //topView右边距与self.view右边距为0 make.height.equalTo(@64); //topView宽度固定为64个像素 }]; [tableView mas_makeConstraints:^(MASConstraintMaker *make) { make.top.equalTo(topView.mas_bottom).with.offset(0); //tableView上边距与self.view下边距为0 make.bottom.equalTo(bottomView.mas_top).with.offset(0); //tableView下边距与self.view上边距为0 make.left.equalTo(self.view.mas_left).with.offset(0); //tableView左边距与self.view左边距为0 make.right.equalTo(self.view.mas_right).with.offset(0); //tableView右边距与self.view右边距为0 }]; //从下往上,从右往左,都是倒推,是负数. UIButton *topButton = [UIButton buttonWithType:UIButtonTypeSystem]; topButton.backgroundColor = [UIColor grayColor]; [topView addSubview:topButton]; [topButton mas_makeConstraints:^(MASConstraintMaker *make) { make.top.equalTo(topView.mas_top).with.offset(20); //从下往上,从右往左,都是倒推,是负数. make.bottom.equalTo(topView.mas_bottom).with.offset(-5); make.right.equalTo(topView.mas_right).with.offset(-20); make.width.equalTo(@100); }]; [table mas_makeConstraints:^(MASConstraintMaker *make) { make.left.equalTo(self.view.mas_left).with.offset(0); make.right.equalTo(self.view.mas_right).with.offset(0); //table的上边距和topView的下边距为0 make.top.equalTo(topView.mas_bottom).with.offset(0); //table的下边距和bottomView的上边距为0 make.bottom.equalTo(bottomView.mas_top).with.offset(0); }];转载地址：http://peyni.baihongyu.com/