问题描述
我正在开发一个支持纵向和横向模式的应用程序.我正在使用 auto layout 来安排我的视图.由于我阅读了很多帖子，并且我意识到开发人员通常使用以下方法之一.
I am developing an application which supports portrait and landscape modes. I am using auto layout to arrange my views. As i have been reading many posts and i have realized that developers commonly use one among the following approaches.
1.第一种方法:
实现UIViewController:updateConstraints方法，根据设备方向更新约束.
Implement the UIViewController:updateConstraints method and update constraints according to device orientation.
<强>2.第二种方法:
实现UIViewController:viewWillLayoutSubviews方法，根据设备方向更新约束.
Implement the UIViewController:viewWillLayoutSubviews method and update constraints according to device orientation.
谁能告诉我最好的使用方法是什么?我一直在寻找结合自动旋转和自动布局的最佳实践，但还没有.谢谢.
Could anyone please tell me what is the best approach to use ? I have been searching for a best practice to combine autorotation and auto layout and nothing yet. Thanks.
推荐答案
我会使用这个 UIViewController 的方法:
I would use this UIViewController's method:
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation 持续时间:(NSTimeInterval)duration;
在旋转时调用，并从那里调用 -setNeedsUpdateConstraints.如果您需要进行额外的计算或管理约束添加
that is called upon rotation, and call -setNeedsUpdateConstraints from there.
If you need to do additional calculations or manage the contrainsts add
- (void)updateViewConstraints
{
[super updateViewConstraints];
// do calculations if needed, like set constants
}
这篇关于自动布局和设备方向的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！