nbsp; views:NSDictionaryOfVariableBindings(newView, self.view)]];
[self.view addConstraints:constraintArray];
}</span>
（3）第三方
UIView-AutoLayout
- <span style="font-size:12px;">- (void)viewDidLoad {
- [super viewDidLoad];
- self.view.translatesAutoresizingMaskIntoConstraints =NO;
-
- UIView *newView = [UIView new];
- newView.backgroundColor = [UIColor greenColor];
- [self.view addSubview:newView];
- newView.translatesAutoresizingMaskIntoConstraints =NO;
-
- [newView autoPinEdgeToSuperviewEdge:ALEdgeLeading withInset:20.0f];
- [newView autoPinEdgeToSuperviewEdge:ALEdgeTrailing withInset:20.0f];
- [newView autoPinEdgeToSuperviewEdge:ALEdgeTop withInset:20.0f];
- [newView autoPinEdgeToSuperviewEdge:ALEdgeBottom withInset:20.0f];
- }</span>
以上3种方式都实现了我们想要的效果，看来代码实现autolayout也不是那么复杂！
例子2:通过上边例子我们实现一个简单的UI布局，下面来一个稍微复杂点的，把上一篇中提到3个view布局的那个例子用代码布局实现一下，但难度有所增加，当size class切换的时候，页面布局发生相应的改变，效果如图：
首先初始化3个View：
- <span style="font-size:12px;">- (UIView *) alView {
- UIView *newView = [UIView new];
- newView.translatesAutoresizingMaskIntoConstraints =NO;
-
- return newView;
- }
- UIView *greenView = [self alView];
- greenView.backgroundColor = [UIColor greenColor];
- [self.view addSubview:greenView];
- UIView *yellowView = [self alView];
- yellowView.backgroundColor = [UIColor yellowColor];
- [self.view addSubview:yellowView];
- UIView *blueView = [self alView];
- blueView.backgroundColor = [UIColor blueColor];
- [self.view addSubview:blueView];</span>
接下来适配竖屏的约束：
- <span style="font-size:12px;">- (NSMutableArray *) portrai
