我正在尝试使用自定义转场来执行一种缩放动画。 执行转换时，sourceViewController 变黑，然后发生缩放。

还尝试将 pushViewController: 设置为完成 block ，但根本不执行转换。

- (void)perform {

    UIViewController *sourceViewController = (UIViewController *) self.sourceViewController;
    UIViewController *destinationViewController = (UIViewController *) self.destinationViewController;

    [destinationViewController.view setTransform:CGAffineTransformMakeScale(0.5,0.5)];
    [destinationViewController.view setAlpha:0.0];

    [UIView animateWithDuration:0.5
                          delay:0.0
                        options:UIViewAnimationCurveEaseOut 
                     animations:^{
                         [destinationViewController.view setTransform:CGAffineTransformMakeScale(1.0,1.0)];
                         [destinationViewController.view setAlpha:1.0];
                         [sourceViewController.navigationController pushViewController:destinationViewController animated:NO];
                     } 
                     completion:^(BOOL finished){
                     }];

}

我做错了什么？

最佳答案

感觉很笨拙，但您可以尝试在动画之前添加 destinationViewController.view 作为 subview ，然后在动画完成后将其移除并在没有动画的情况下将其推回。解决了转场前的黑屏，但可能并不完美，这取决于你想用导航栏做什么，但也许更接近:

[sourceViewController.view addSubview:destinationViewController.view];
[destinationViewController.view setFrame:sourceViewController.view.window.frame];
[destinationViewController.view setTransform:CGAffineTransformMakeScale(0.5,0.5)];
[destinationViewController.view setAlpha:1.0];

[UIView animateWithDuration:0.5
                      delay:0.0
                    options:UIViewAnimationCurveEaseOut 
                 animations:^{
                     [destinationViewController.view setTransform:CGAffineTransformMakeScale(1.0,1.0)];
                     [destinationViewController.view setAlpha:1.0];
                 } 
                 completion:^(BOOL finished){
                     [destinationViewController.view removeFromSuperview];
                     [sourceViewController.navigationController pushViewController:destinationViewController animated:NO];
                 }];

请注意，从 iOS 7 开始，您将使用自定义过渡。有关详细信息，请参阅 WWDC 2013 Custom Transitions Using View Controllers .

例如，如果尝试使用导航 Controller 进行自定义转换，第一个 View Controller 会将自己指定为导航 Controller 的委托(delegate):

self.navigationController.delegate = self;

然后，它将分别为 push 和 pop 指定自定义动画:

- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
                                  animationControllerForOperation:(UINavigationControllerOperation)operation
                                               fromViewController:(UIViewController *)fromVC
                                                 toViewController:(UIViewController *)toVC
{
    if (operation == UINavigationControllerOperationPush) {
        return [[PushAnimator alloc] init];
    } else {
        return [[PopAnimator alloc] init];
    }
}

然后你显然会实现这些动画师:

@interface PushAnimator : NSObject <UIViewControllerAnimatedTransitioning>

@end

@implementation PushAnimator

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
    return 0.5;
}

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController* toViewController   = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIViewController* fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];

    [[transitionContext containerView] addSubview:toViewController.view];
    toViewController.view.frame = fromViewController.view.frame;
    toViewController.view.transform = CGAffineTransformMakeScale(0.5,0.5);
    toViewController.view.alpha = 0.0;

    [UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0.0 options:0 animations:^{
        toViewController.view.transform = CGAffineTransformIdentity;
        toViewController.view.alpha = 1.0;
    } completion:^(BOOL finished) {
        [fromViewController.view removeFromSuperview];
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    }];
}

@end

和

@interface PopAnimator : NSObject <UIViewControllerAnimatedTransitioning>

@end

@implementation PopAnimator

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
    return 0.5;
}

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController* toViewController   = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIViewController* fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];

    [[transitionContext containerView] insertSubview:toViewController.view belowSubview:fromViewController.view];
    toViewController.view.frame = fromViewController.view.frame;

    [UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0.0 options:0 animations:^{
        fromViewController.view.transform = CGAffineTransformMakeScale(0.5,0.5);
        fromViewController.view.alpha = 0.0;
    } completion:^(BOOL finished) {
        [fromViewController.view removeFromSuperview];
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    }];
}

@end

关于ios - 自定义转场动画，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10779563/