使用UIPickerView委託方法的問題

Question

我有一個UIPicker並設置了我的委託方法。

我想在用戶對所選擇的選取器項目進行TAPS時發生某些事情。處理它在：

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

觸發事件發生時，未選擇未點擊選擇器項目。

如何在觸摸選定的選取器項目時觸發事件？

Answer 1

你必須子類UIPickerView並手動檢測那裏的觸摸。是的，它看起來很混亂。但這似乎是做到這一點的唯一方法。下面的代碼可能會有幫助，

@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; 
} 

編號：Responding to touchesBegan in UIPickerView instead of UIView