在uiScrollView中使用uiTouch

(如果我正确理解这个问题)

uiScrollView截取 touchMoved 如果启用滚动,则不会将事件传播到其内容。因此,要在应用程序的uiscrollview内容中进行拖动,我执行了以下技巧:

触摸开始: 检查是否触摸“可拖动”区域。如果是-在uiscrollview中禁用滚动。

触摸移动: 现在,当禁用滚动时,内容视图将接收此事件,您可以相应地移动可拖动的uiImageView。

触摸屏: 在uiscrollew中重新启用滚动。

如果要将视图拖到可见的uiscrollview区域之外,您可能还需要手动检查是否靠近边界,并手动调整内容偏移量(我自己没有尝试过,但我认为应该可以)。

实现这一点的最佳方法是将uiscrollview类本身子类化,然后在子类中添加touches-begind事件方法。这对我有用。

(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{

NSLog(@"DEBUG: Touches began" );

UITouch *touch = [[event allTouches] anyObject];

[super touchesBegan:touches withEvent:event];
}

(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {

NSLog(@"DEBUG: Touches cancelled");

// Will be called if something happens - like the phone rings

UITouch *touch = [[event allTouches] anyObject];

[super touchesCancelled:touches withEvent:event];

}


(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

NSLog(@"DEBUG: Touches moved" );

UITouch *touch = [[event allTouches] anyObject];

[super touchesMoved:touches withEvent:event];

}

(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(@"DEBUG: Touches ending" );
//Get all the touches.
NSSet *allTouches = [event allTouches];

//Number of touches on the screen
switch ([allTouches count])
{
    case 1:
    {
        //Get the first touch.
        UITouch *touch = [[allTouches allObjects] objectAtIndex:0];

        switch([touch tapCount])
        {
            case 1://Single tap

                break;
            case 2://Double tap.

                break;
        }
    }
        break;
}
[super touchesEnded:touches withEvent:event];
}