我有一个视图控制器布局在故事板中启用自动布局,我正在寻找一种方法来更改约束,以允许我的视图旋转到横向和重新排列屏幕上的按钮.当我尝试下面的代码时,我得到了大约二十几个"无法满足约束,打破约束......"消息,我无法真正解码.
有没有办法用编程方式指定的约束动态替换故事板中的约束?我想完全覆盖我在故事板中定义的按钮的布局.
-(void)updateViewConstraints
{
[super updateViewConstraints];
self.loginButton.translatesAutoresizingMaskIntoConstraints = NO;
self.getStartedButton.translatesAutoresizingMaskIntoConstraints = NO;
self.takeTourButton.translatesAutoresizingMaskIntoConstraints = NO;
[self.loginButton removeConstraints:self.loginButton.constraints];
[self.getStartedButton removeConstraints:self.getStartedButton.constraints];
[self.takeTourButton removeConstraints:self.takeTourButton.constraints];
one = self.loginButton;
two = self.getStartedButton;
three = self.takeTourButton;
NSDictionary *metrics = @{@"height":@50.0,@"width":@100.0,@"leftSpacing":@110.0};
NSDictionary *views = NSDictionaryOfVariableBindings(one,two,three);
[self.view removeConstraints:activeTestLabelConstraints];
[activeTestLabelConstraints removeAllObjects];
if(isRotatingToLandscape)
{
[self registerConstraintsWithVisualFormat:@"|-[one(two)]-[two(three)]-[three]-|" options:NSLayoutFormatAlignAllTop | NSLayoutFormatAlignAllBottom metrics:metrics views:views];
[self registerConstraintsWithVisualFormat:@"V:[one(height)]-|" options:0 metrics:metrics views:views];
}else
{
[self registerConstraintsWithVisualFormat:@"|-leftSpacing-[one(width)]" options:0 metrics:metrics views:views];
[self registerConstraintsWithVisualFormat:@"[two(width)]" options:0 metrics:metrics views:views];
[self registerConstraintsWithVisualFormat:@"[three(width)]" options:0 metrics:metrics views:views];
[self registerConstraintsWithVisualFormat:@"V:[one(height)]-[two(75)]-[three(100)]-|" options:NSLayoutFormatAlignAllCenterX metrics:metrics views:views];
} …Run Code Online (Sandbox Code Playgroud)