如何在与 panGestureRecoginizer 的交互过渡中使用 pushViewController

Question

我尝试实现一个使用 Pan Gesture 的简单交互过渡。它看起来像在这个video.
我有使用情节提要的示例项目。该项目位于此link。
但是，如果我将 ViewController 的第 50 行中的“performSegueWithIdentifier ...”替换为第 51 行中注释掉的“pushViewController:controller”。平移手势立即被取消.调用“performSegueWithIdentifier”和“pushViewController:controller”有什么区别。他们基本上只是推送到另一个视图控制器。有什么建议我可以使用 pushViewController 方法调用而不是调用 performSegueWithIdentifier 吗？任何见解将不胜感激。

switch (panGuesture.state)
{
    case UIGestureRecognizerStateBegan:
        NSLog(@"======================UIGestureRecognizerStateBegan");
        [self performSegueWithIdentifier:@"pushNP" sender:panGuesture]; //line 50
        [self.navigationController pushViewController:controller animated:YES]; //line 51
        break;
    case UIGestureRecognizerStateChanged:
        NSLog(@"======================UIGestureRecognizerStateChanged");
        float percentageOfPan = [self percentageOfPan:touchLocation];
        NSLog(@"=======percentageOfPan:%f",percentageOfPan);
        [self.transition updateInteractiveTransition:percentageOfPan];
        break;
    case UIGestureRecognizerStateCancelled:
        NSLog(@"======================UIGestureRecognizerStateCancelled");
        break;
    case UIGestureRecognizerStateEnded:
        NSLog(@"======================UIGestureRecognizerStateEnded");
        if(touchLocation.y < 600){
            [self.transition finishInteractiveTransition];
        } else {
            [self.transition cancelInteractiveTransition];
        }
        break;
    default:
        break;
}

Answer 1

这两种不同的方法是实例化两个不同的视图控制器。 segue 实例化了您在情节提要中拥有的 NPViewController 的实例，而当您执行推送时，您正在推送您分配初始化的普通 UIViewController。

平移手势识别器处理程序的前几行应如下所示，

- (void)pan:(UIPanGestureRecognizer*)panGuesture{
    CGPoint touchLocation = [panGuesture locationInView:self.view];
    NSLog(@"==========pan touch location:%f,%f",touchLocation.x,touchLocation.y);
    //UIViewController *controller = [[UIViewController alloc]init];
    NPViewController *controller = [self.storyboard instantiateViewControllerWithIdentifier:@"NPViewController"];
    controller.view.backgroundColor = [UIColor whiteColor];
    switch (panGuesture.state)
    {
        case UIGestureRecognizerStateBegan:
            NSLog(@"======================UIGestureRecognizerStateBegan");
           // [self performSegueWithIdentifier:@"pushNP" sender:panGuesture];
            [self.navigationController pushViewController:controller animated:YES];
            break;

我已经注释掉了用于实例化 UIViewController 的行。确保在情节提要中为 NPViewController 添加标识符。