Iphone UILongPressGestureRecognitor不工作

我正在尝试创建一个应用程序，当启动UILongPressGestureRecognitor手势时，可以拖放UIButtons。事实上，我的应用程序在任何iPad上都运行良好。它只会在iPhone上产生问题，并且低于iOS 5.0，因为它在配备iOS 5.0的iPhone上工作正常

UILongPressGestureRecognizer * gesture = [[UILongPressGestureRecognizer alloc] initWithTarget: self action: @selector(moveActionGestureRecognizerStateChanged:)];
gesture.minimumPressDuration = 0.5;
gesture.delegate = self;
[self.dragView addGestureRecognizer: gesture];
[gesture release]; 

- (void) moveActionGestureRecognizerStateChanged: (UILongPressGestureRecognizer *) recognizer
{
    switch ( recognizer.state )
    {
        default:
        case UIGestureRecognizerStateFailed:
        {
            dragView.alpha=1.0;
            [dragView release];
            dragView=nil;
            break;
        }
        case UIGestureRecognizerStatePossible:
        {
               dragView.alpha=0.8;
            dragView.frame=CGRectMake(dragView.frame.origin.x, dragView.frame.origin.y, dragView.frame.size.width, dragView.frame.size.height);
        }
        case UIGestureRecognizerStateCancelled:
        {
            dragView.alpha=1.0;
            [dragView release];
            dragView=nil;
            break;
        }            
        case UIGestureRecognizerStateEnded:
        {
            //Set dragView on target position

            break;
        }
        case UIGestureRecognizerStateBegan:
        {
            //NSLog(@"Began");
            dragView.alpha=0.8;        
            dragView.frame=CGRectMake(dragView.frame.origin.x, dragView.frame.origin.y, dragView.frame.size.width, dragView.frame.size.height);
            [self bringSubviewToFront:dragView];
            break;
        }           
        case UIGestureRecognizerStateChanged:
        {
            [self.view bringSubviewToFront:dragView];
            CGPoint offset = [recognizer locationInView: self.scrollView];
            dragView.frame=CGRectMake(offset.x, offset.y, dragView.frame.size.width, dragView.frame.size.height);
        }            
            break;
    }
}

我有两台设备，分别是iPhone3G和iPhone4。此功能在配备iOS 5.0的iPhone4中运行良好，但在配备iOS 4.2.1的iPhone3G中运行不正常。有时它在iPhone3G中工作，但有时它不调用委托方法

如果你有什么解决办法，请告诉我

---

谢谢

是否根本不调用委托方法，或者是否未选择任何案例？我不知道这是否真的解决了您的问题，但您应该修复您的

开关

（在默认情况下获取战利品）：

---

感谢这项工作，但在iPhone3G中，有时会调用委托方法“MoveActionGestureRecognitzerStateChanged”。所以它有时不起作用。如果我遗漏了什么，请告诉我。

switch ( recognizer.state )
{
    case someCase:
    {
        // ...
        break;
    }

    default:
        break;
}