使用UIPickerView委托方法的问题

Question

我有一个UIPicker并设置了我的委托方法。

我想在用户对所选择的选取器项目进行TAPS时发生某些事情。处理它在：

- (void)pickerView:(UIPickerView *)aPickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component 

触发事件发生时，未选择未点击选择器项目。

如何在触摸选定的选取器项目时触发事件？

Answer 1

你必须子类UIPickerView并手动检测那里的触摸。是的，它看起来很混乱。但这似乎是做到这一点的唯一方法。下面的代码可能会有帮助，

@interface TouchDetectionView : UIPickerView { 

} 
- (UIView *)getNextResponderView:(NSSet *)touches withEvent:(UIEvent *)event; 
@end 
@implementation TouchDetectionView 

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UIView * hitTestView = [self getNextResponderView:touches withEvent:event]; 
    [hitTestView touchesBegan:touches withEvent:event]; 
} 

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UIView * hitTestView = [self getNextResponderView:touches withEvent:event]; 
    [hitTestView touchesMoved:touches withEvent:event]; 
} 

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UIView * hitTestView = [self getNextResponderView:touches withEvent:event]; 
    [hitTestView touchesEnded:touches withEvent:event]; 
} 

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UIView * hitTestView = [self getNextResponderView:touches withEvent:event]; 
    [hitTestView touchesCancelled:touches withEvent:event]; 
} 

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event 
{ 
    return self; 
} 

- (UIView *)getNextResponderView:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UITouch * touch = [touches anyObject]; 
    CGPoint point = [touch locationInView:self]; 
    UIView * hitTestView = [super hitTest:point withEvent:event]; 

    return (hitTestView == self) ? nil : hitTestView; 
} 

编号：Responding to touchesBegan in UIPickerView instead of UIView