iOS - UILayoutGuide和NSLayoutAnchor实现自动布局

@interface ViewController ()
{
    NSLayoutConstraint *yellowViewTopConstraint;
    NSLayoutConstraint *blueViewLeadConstraint;
  
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
   
    
    UILayoutGuide *view_Guide = self.view.layoutMarginsGuide;
    
    /**
       左边黄色view
     */
    UIView *yellow_View = [[UIView alloc]init];
    yellow_View.backgroundColor = [UIColor yellowColor];
    yellow_View.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:yellow_View];
    //左边距约束
    NSLayoutConstraint *yellowView_Leading = [yellow_View.leadingAnchor constraintEqualToAnchor:view_Guide.leadingAnchor constant:10];
    //顶部约束
    NSLayoutConstraint *yellowView_Top = [yellow_View.topAnchor constraintEqualToAnchor:view_Guide.topAnchor constant:84];
    //宽度约束
    NSLayoutConstraint *yellowView_Width = [yellow_View.widthAnchor constraintEqualToConstant:100];
    //高度约束
    NSLayoutConstraint *yellow_Height = [yellow_View.heightAnchor constraintEqualToConstant:100];
    [NSLayoutConstraint activateConstraints:@[yellowView_Leading,yellowView_Top,yellow_Height,yellowView_Width]];
    
    yellowViewTopConstraint = yellowView_Top;
    
    
    /**
        居中的红色view
     */
    UIView *middleView = [[UIView alloc]init];
    middleView.backgroundColor = [UIColor redColor];
    middleView.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:middleView];
    //水平居中
    NSLayoutConstraint *middleView_CenterX = [middleView.centerXAnchor constraintEqualToAnchor:view_Guide.centerXAnchor];
    //垂直居中
    NSLayoutConstraint *middleView_CenterY = [middleView.centerYAnchor constraintEqualToAnchor:view_Guide.centerYAnchor];
     //宽度约束
    NSLayoutConstraint *middleView_Width = [middleView.widthAnchor constraintEqualToConstant:100];
    //高度约束
    NSLayoutConstraint *middleView_Height = [middleView.heightAnchor constraintEqualToConstant:100];
    [NSLayoutConstraint activateConstraints:@[middleView_CenterX,middleView_CenterY,middleView_Height,middleView_Width]];
    
    
    
    /**
     * 创建一个与黄色view相聚10的蓝色view
     */
    UIView *blueView = [[UIView alloc]init];
    blueView.backgroundColor = [UIColor blueColor];
    blueView.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:blueView];
    //左边约束
    NSLayoutConstraint *blueView_Leading = [blueView.leadingAnchor constraintEqualToAnchor:yellow_View.trailingAnchor constant:10];
    //顶部约束于黄色view顶部对齐
    NSLayoutConstraint *blueView_Top = [blueView.topAnchor constraintEqualToAnchor:yellow_View.topAnchor];
    //宽度约束
    NSLayoutConstraint *blueView_Width = [blueView.widthAnchor constraintEqualToConstant:100];
    //高度约束
    NSLayoutConstraint *blueView_Height = [blueView.heightAnchor constraintEqualToConstant:100];
    [NSLayoutConstraint activateConstraints:@[blueView_Leading,blueView_Top,blueView_Width,blueView_Height]];
    
    blueViewLeadConstraint = blueView_Leading;
    
    //创建一个执行动画按钮
    
    UIButton *btnAnimate = [UIButton buttonWithType:UIButtonTypeCustom];
    [btnAnimate setBackgroundColor:[UIColor redColor]];
    [btnAnimate setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [btnAnimate setTitle:@"执行动画" forState:UIControlStateNormal];
    [btnAnimate addTarget:self action:@selector(btnAnimateClick:) forControlEvents:UIControlEventTouchUpInside];
    btnAnimate.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:btnAnimate];
    //水平居中
    NSLayoutConstraint *btnAnimate_CenterX = [btnAnimate.centerXAnchor constraintEqualToAnchor:view_Guide.centerXAnchor];
    //底部约束
    NSLayoutConstraint *btnAnimate_Bottom = [btnAnimate.bottomAnchor constraintEqualToAnchor:view_Guide.bottomAnchor constant:-20];

    //宽度约束
    NSLayoutConstraint *btnAnimate_Width = [btnAnimate.widthAnchor constraintEqualToConstant:80];
    //高度约束
    NSLayoutConstraint *btnAnimate_Height = [btnAnimate.heightAnchor constraintEqualToConstant:32];
    
    
    [NSLayoutConstraint activateConstraints:@[btnAnimate_Height,btnAnimate_Width,btnAnimate_CenterX,btnAnimate_Bottom]];
      
}

- (void)btnAnimateClick:(UIButton *)sender
{

  [UIView animateKeyframesWithDuration:1 delay:0 options:UIViewKeyframeAnimationOptionRepeat animations:^{
      
      yellowViewTopConstraint.constant += 10;
      blueViewLeadConstraint.constant += 10;
      [self.view layoutIfNeeded];
      
      
  } completion:^(BOOL finished) {
      
      
  }];
        
}

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