iOS手势识别左滑pop页面的常见处理

在iOS的手势识别中,有时我们要用手势实现页面pop(比如微信的左滑返回),实现时UIGestureRecognizerDelegate,会有这么一个(可选的)方法:

// called when a gesture recognizer attempts to transition out of UIGestureRecognizerStatePossible. returning NO causes it to transition to UIGestureRecognizerStateFailed

– (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer;

实现它有一些常见的处理,比如:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
    // Don't handle gestures if navigation controller is still animating a transition
    if ([self.navigationController.transitionCoordinator isAnimated])
        return NO;

    if (self.navigationController.viewControllers.count < 2)
        return NO;

    return YES;
}

解释一下,第一个是说如果仍然在transaction的动画中,不识别,第二个是说如果小于2个不识别(因为没的可pop了)。

顺便说一下,这个左滑pop的手势是iOS的navigationController自带的:

self.navigationController.interactivePopGestureRecognizer.delegate = self;
self.navigationController.interactivePopGestureRecognizer.enabled = YES;

 

Leave a Reply

Your email address will not be published.