IOS/Objective-C/Storyboard：自定义Segue从左到右在视图控制器之间创建黑条

Question

我将 UIStoryboardSegue 子类化以创建从左到右的 Segue。 segue 工作，但是，有一个黑色的垂直条或背景在两个视图控制器之间暂时可见，这会破坏效果。 （我希望 segue 看起来像一个正常的从右到左的显示 segue，但方向相反）。有谁知道这可能是什么原因或如何摆脱它？这是我的代码：

#import "customSegue.h"
#import "QuartzCore/QuartzCore.h"

@implementation customSegue

-(void)perform {

    UIViewController *sourceViewController = (UIViewController*)[self sourceViewController];
    UIViewController *destinationController = (UIViewController*)[self destinationViewController];

    CATransition* transition = [CATransition animation];
    transition.duration = .25;
    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    transition.type = kCATransitionPush; //kCATransitionMoveIn; //, kCATransitionPush, kCATransitionReveal, kCATransitionFade
    transition.subtype = kCATransitionFromLeft; //kCATransitionFromLeft, kCATransitionFromRight, kCATransitionFromTop, kCATransitionFromBottom



    [sourceViewController.navigationController.view.layer addAnimation:transition
                                                                forKey:kCATransition];

    [sourceViewController.navigationController pushViewController:destinationController animated:NO];

}
@end

编辑：

我想我会收集一些我发现的建议修复，尽管没有一个对我有用。

将呈现视图控制器的背景颜色设置为白色

Set self.definesPresentationContext = YES; 在呈现视图控制器上或从接受的答案 here 中检查情节提要中 VC 的“定义上下文”。

指定上下文如下：

UIViewController *rootViewController = [UIApplication sharedApplication].delegate.window.rootViewController;
    rootViewController.modalPresentationStyle = UIModalPresentationCurrentContext;
    UIViewController *destinationController = (UIViewController*)[self destinationViewController]
    [sourceViewController presentViewController:destinationController animated:NO completion:nil];

来自接受的答案here。

Answer 1

您看到的是视图在动画开始和结束附近的不透明度变化，因此您看到的“黑条”实际上是背景窗口。虽然它可能并不完美，但快速解决方法是更改​​窗口的背景颜色以匹配目标视图控制器的背景颜色（然后在转换完成后根据需要将其设置回来）。

这是您的代码示例，并进行了必要的修改：

-(void)perform {
    UIViewController *sourceViewController = (UIViewController*)[self sourceViewController];
    UIViewController *destinationController = (UIViewController*)[self destinationViewController];

    CATransition* transition = [CATransition animation];
    CGFloat animationDuration = 0.25f;
    transition.duration = animationDuration;
    transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    transition.type = kCATransitionPush; //kCATransitionMoveIn; //, kCATransitionPush, kCATransitionReveal, kCATransitionFade
    transition.subtype = kCATransitionFromLeft; //kCATransitionFromLeft, kCATransitionFromRight, kCATransitionFromTop, kCATransitionFromBottom
    transition.fillMode = kCAFillModeForwards;



    [sourceViewController.navigationController.view.layer addAnimation:transition
                                                                forKey:kCATransition];
    // hold onto the previous window background color
    UIColor *previousWindowBackgroundColor = sourceViewController.view.window.backgroundColor;
    // switch the window background color to match the destinationController's background color temporarily
    sourceViewController.view.window.backgroundColor = destinationController.view.backgroundColor;
    // do the transition
    [sourceViewController.navigationController pushViewController:destinationController animated:NO];
    // switch the window color back after the transition duration from above
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(animationDuration * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        // make sure we still have a handle on the destination controller
        if (destinationController) {
            destinationController.view.window.backgroundColor = previousWindowBackgroundColor;
        }
    });
}

以下是过渡减慢到 2 秒的示例：

Slowed down transition

还有 0.25 的动画，就像您在代码中所拥有的那样：

Your speed transition