PureLayout

PureLayout 是 iOS & OS X Auto Layout 的终极 API——非常简单，又非常强大。PureLayout 通过一个全面的Auto Layout API 扩展了 UIView/NSView, NSArray 和 NSLayoutConstraint，仿照苹果自身的框架, 构建了一个全面的自动布局 API, 这样你再也不用为适配而苦恼啦!!!

添加PureLayout到你的工程里面

• 用CocoaPods安装（podilfe中加pod 'PureLayout'）/GitHub下载PureLayout, 手动添加到你的项目中
• 导入头文件#import <PureLayout/PureLayout.h> /  #import "PureLayout.h"

我们就这个布局来简单说一下

首先新建几个 View

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@property (nonatomic, strong) UIView *blueView; @property (nonatomic, strong) UIView *redView; @property (nonatomic, strong) UIView *yellowView; @property (nonatomic, strong) UIView *greenView; @property (nonatomic, assign) BOOL didSetupConstraints; // 判断是否存在约束条件

然后在加载试图

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- (void)loadView { self.view = [UIView new]; self.view.backgroundColor = [UIColor colorWithWhite:0.1 alpha:1.0]; [self.view addSubview:self.blueView]; [self.view addSubview:self.redView]; [self.view addSubview:self.yellowView]; [self.view addSubview:self.greenView]; [self.view setNeedsUpdateConstraints]; // 设置新的约束天剑 }

如果没有试图,那么就重新创建一个

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- (UIView *)blueView { if (!_blueView) { _blueView = [UIView newAutoLayoutView]; _blueView.backgroundColor = [UIColor blueColor]; } return _blueView; } - (UIView *)redView { if (!_redView) { _redView = [UIView newAutoLayoutView]; _redView.backgroundColor = [UIColor redColor]; } return _redView; } - (UIView *)yellowView { if (!_yellowView) { _yellowView = [UIView newAutoLayoutView]; _yellowView.backgroundColor = [UIColor yellowColor]; } return _yellowView; } - (UIView *)greenView { if (!_greenView) { _greenView = [UIView newAutoLayoutView]; _greenView.backgroundColor = [UIColor greenColor]; } return _greenView; }

然后再添加试图的约束条件

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- (void)updateViewConstraints //更新约束条件 { // 如果没有自动约束条件 if (!self.didSetupConstraints) { // Blue view is centered on screen,(Centers the view in its superview.) with size {50 pt, 50 pt} //设置蓝色的 view 在父试图的中心, [self.blueView autoCenterInSuperview]; //设置蓝色的 view 的宽和高(50.0 50.0) [self.blueView autoSetDimensionsToSize:CGSizeMake(50.0, 50.0)]; // Red view is positioned at the bottom right corner of the blue view, with the same width, and a height of 40 pt // 设置红色 view 的顶部是蓝色 view 的底部 [self.redView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.blueView]; //设置红色 view 的左边是蓝色 view 的右边 [self.redView autoPinEdge:ALEdgeLeft toEdge:ALEdgeRight ofView:self.blueView]; //设置红色 view 的宽度就是蓝色 view 的宽度 [self.redView autoMatchDimension:ALDimensionWidth toDimension:ALDimensionWidth ofView:self.blueView]; //设置红色 view 的高度为40.0 [self.redView autoSetDimension:ALDimensionHeight toSize:40.0]; // Yellow view is positioned 10 pt below the red view, extending across the screen with 20 pt insets from the edges, // and with a fixed height of 25 pt //设置黄色 veiw 的顶部距离红色 view 距离为10.0 [self.yellowView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.redView withOffset:10.0]; //设置黄色 view 的高度为25.0 [self.yellowView autoSetDimension:ALDimensionHeight toSize:25.0]; //设置黄色 view 距离父试图左边的距离为20.0 [self.yellowView autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:20.0]; //设置黄色 view 距离父试图右边的距离为20.0 [self.yellowView autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:20.0]; // Green view is positioned 10 pt below the yellow view, aligned to the vertical axis of its superview, // with its height twice the height of the yellow view and its width fixed to 150 pt //设置绿色 view 的顶部距离黄色 view 的底部距离为10.0 [self.greenView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.yellowView withOffset:10.0]; //设置绿色 view 相对父试图竖向居中 [self.greenView autoAlignAxisToSuperviewAxis:ALAxisVertical]; //设置绿色的 view 的高度是黄色 view 高度的2.0倍 [self.greenView autoMatchDimension:ALDimensionHeight toDimension:ALDimensionHeight ofView:self.yellowView withMultiplier:2.0]; //设置绿色 view 的宽度为150.0 [self.greenView autoSetDimension:ALDimensionWidth toSize:150.0]; //设置已经添加过约束了 self.didSetupConstraints = YES; } [super updateViewConstraints]; }

github 地址:https://github.com/smileyborg/PureLayout#