iphone - 与 interactivePopGestureRecognizer 一起调整位置

Question

我有一个自定义控件，包含一行按钮，模仿标签栏。此控件在 UINavigationController 离开 Root View Controller 时滑出 View ，并在导航到 Root View Controller 时滑回。

在 iOS 7 中，UIScreenEdgePanGestureRecognizer 提供了滑动返回手势。因此，我正在修改我的自定义控件，以便滑动量对应于 UIScreenEdgePanGestureRecognizer 的翻译。

问题是，当用户释放触摸时，我如何判断 UINavigationController 将导航回或弹回原始 View ？

[self.interactivePopGestureRecognizer addTarget:self action:@selector(panningBack:)];


- (void) panningBack:(UIPanGestureRecognizer *)recognizer
{
    // Snipped - Code that reads the recognizer translation and adjust custom control y position

    if (recognizer.state == UIGestureRecognizerStateEnded)
    {
        // Question: Does it go back, or does it not?

        // If it goes back, slide custom control into view
        // Else slide custom control out of view
    }
}

Answer 1

我知道这是一个相当古老的问题，所以答案可能对 OP 没有用，但可能对其他人有用。我昨天遇到了同样的问题，并且在 SO 和网络的其余部分进行了大量搜索，但没有真正找到任何东西。所以这是我用于类似问题的解决方案。这是在 navigationcontroller 委托(delegate)中实现的，但我想如果更适合您的需要，您可以在其他地方进行。

    - (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    id<UIViewControllerTransitionCoordinator> tc = navigationController.topViewController.transitionCoordinator;
    [tc notifyWhenInteractionEndsUsingBlock:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        NSLog(@"DONE!!!");
        NSLog(@"Container View: %@", [context containerView]);
        NSLog(@"From VC: %@", [context viewControllerForKey:UITransitionContextFromViewControllerKey]);
        NSLog(@"To VC: %@", [context viewControllerForKey:UITransitionContextToViewControllerKey]);
        NSLog(@"Initially Interactive: %i", [context initiallyInteractive]);
        NSLog(@"Completion Curve: %d", [context completionCurve]);
        NSLog(@"Is Animated: %i", [context isAnimated]);
        NSLog(@"Is Cancelled: %i", [context isCancelled]);
        NSLog(@"Is Interactive: %i", [context isInteractive]);
        NSLog(@"Percent Complete: %f", [context percentComplete]);
        NSLog(@"Presentation Style: %d", [context presentationStyle]);
        NSLog(@"Transition Duration: %f", [context transitionDuration]);
    }];
}

当用户抬起她的手指并且动画相当反转或完成时，这将触发。 [context isCancelled]; 会告诉你它是反转的还是完成的。上下文对象中还有许多其他有用的信息可供使用。