- (void)createThreeViews{
//1 创建3个view的对象
UIView *leftView = [[UIView alloc]init];
UIView *rightView = [[UIView alloc]init];
UIView *bottomView = [[UIView alloc]init];
//2 设置背景颜色
leftView.backgroundColor = [UIColor greenColor];
rightView.backgroundColor = [UIColor purpleColor];
bottomView.backgroundColor = [UIColor orangeColor];
//3 添加视图上显示
[self.view addSubview:leftView];
[self.view addSubview:rightView];
[self.view addSubview:bottomView];
//4 关闭系统的自定义布局
leftView.translatesAutoresizingMaskIntoConstraints = NO;
rightView.translatesAutoresizingMaskIntoConstraints = NO;
bottomView.translatesAutoresizingMaskIntoConstraints = NO;
//leftView的上 = self.view的上+20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:leftView
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeTop
multiplier:1.
constant:20]];
// leftView的左 = self.view的左 + 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:leftView
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeLeft
multiplier:1.
constant:20]];
// rightView的上 = leftView的上
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:rightView
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeTop
multiplier:1.
constant:0]];
// rightView的左 = leftView的右 + 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:rightView
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeRight
multiplier:1.
constant:20]];
// rightView的右 = self.view的右 - 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:rightView
attribute:NSLayoutAttributeRight
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeRight
multiplier:1.
constant:-20]];
// rightView的高 = leftView的高
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:rightView
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeHeight
multiplier:1.
constant:0]];
// rightView的宽 = leftView的宽
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:rightView
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeWidth
multiplier:1.0
constant:0]];
//bottomView的左 = self.view的左 + 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:bottomView
attribute:NSLayoutAttributeLeft
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeLeft
multiplier:1
constant:20]];
//bottomView的右 = self.view的右 - 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:bottomView
attribute:NSLayoutAttributeRight
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeRight
multiplier:1
constant:-20]];
//bottomView的上 = leftView的下 + 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:bottomView
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeBottom
multiplier:1
constant:20]];
//bottomView的高 = leftView的高
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:bottomView
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:leftView
attribute:NSLayoutAttributeHeight
multiplier:1
constant:0]];
//bottomView的下 = self.view的下 + 20
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:bottomView
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeBottom
multiplier:1
constant:-20]];
}
Simulator Screen Shot - iPhone X - 2018-04-17 at 10.07.37.png
