iOS presentView相关

Question

想做一个效果：
present一个VC，不让这个VC完全覆盖之前的界面，还要能看见之前的界面。就像系统的UIAlertViewControlle

Answer 1

可以通过 <UIViewControllerAnimatedTransitioning> 自定义页面转场达到该效果，具体可参考我之前写的一个小项目。

先设置 modalPresentationStyle 和 modalTransitionStyle

// iOS8+
self.modalPresentationStyle = UIModalPresentationCustom;
self.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;

然后定一个遵从 UIViewControllerAnimatedTransitioning 协议的动画代理对象，并在内部实现以下方法。

@implementation FEPopupMenuControllerAnimatedTransitioning

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext{
    return 0.25;
}

-(void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext{
}

@end

最后在 VC中 实现 UIViewControllerAnimatedTransitioning 协议，返回钢材定义的转场动画代理对象

#pragma mark <UIViewControllerAnimatedTransitioning>

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
    FEPopupMenuControllerAnimatedTransitioning *transitioning = [FEPopupMenuControllerAnimatedTransitioning new];
    return transitioning;
}

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
    FEPopupMenuControllerAnimatedTransitioning * transitioning = [FEPopupMenuControllerAnimatedTransitioning new];
    return transitioning;
}

详情可参考：Feelinging/FEPopupMenuController