iPhone - UIPickerView 和 UIWebView 上的手势

Posted 2023-02-24

【中文标题】iPhone - UIPickerView 和 UIWebView 上的手势

【英文标题】：iPhone - Gestures on UIPickerView and UIWebView

【发布时间】：2010-02-14 08:03:56

【问题描述】：

我正在制作一个 iPhone 应用程序，用户可以在其中做手势（左右滑动）来浏览标签。我的问题是某些页面具有诸如pickerview、webview、文本字段和按钮之类的视图。滑动不适用于这些。有没有办法拥有全局手势？

作为参考，我的手势代码示例：

//Swipe between tabs
#define mindrag 100
CGPoint mystartTouchPosition;
BOOL isProcessingListMove;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

    UITouch *touch = [touches anyObject];
    CGPoint newTouchPosition = [touch locationInView:self.view];
    if(mystartTouchPosition.x != newTouchPosition.x || mystartTouchPosition.y != newTouchPosition.y) 
        isProcessingListMove = NO;
    
    mystartTouchPosition = [touch locationInView:self.view];
    [super touchesBegan:touches withEvent:event];


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

    UITouch *touch = touches.anyObject;
    CGPoint currentTouchPosition = [touch locationInView:self.view];

    // If the swipe tracks correctly.
    double diffx = mystartTouchPosition.x - currentTouchPosition.x + 0.1; // adding 0.1 to avoid division by zero
    double diffy = mystartTouchPosition.y - currentTouchPosition.y + 0.1; // adding 0.1 to avoid division by zero

    if(abs(diffx / diffy) > 2.5 && abs(diffx) > mindrag)
    
        // It appears to be a swipe.
        if(isProcessingListMove) 
            // ignore move, we're currently processing the swipe
            return;
        

        if (mystartTouchPosition.x < currentTouchPosition.x) 
            isProcessingListMove = YES;
            self.tabBarController.selectedViewController = [self.tabBarController.viewControllers objectAtIndex:1];
            return;
        
        else 
            isProcessingListMove = YES;

            self.tabBarController.selectedViewController = [self.tabBarController.viewControllers objectAtIndex:3];

            return;
        
    
    else if(abs(diffy / diffx) > 1)
    
        isProcessingListMove = YES;
        [super touchesMoved:touches withEvent:event];
    


-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 

    isProcessingListMove = NO;
    [super touchesEnded:touches withEvent:event];

// End of swipe

感谢任何输入。

【参考方案1】：

您可以继承 UIImagePickerController 和 UIWebView 并将这些手势捕获视图添加到它们，只要您的手势检测当然仍然可以将触摸传递给底层视图。

【讨论】：

UIImagePickerController 是一个具有view 属性的控制器。而UIWebView 继承自UIView。