利用UIPanGestureRecognizer 判斷手勢滑動方向

/** 
 *  添加平移手勢 
 * 
 *  @param view 
 */  
- (void)addTapGestureWithView:(UIView *)view  
{  

    UIPanGestureRecognizer *recognizer = [[UIPanGestureRecognizer alloc]  
                                          initWithTarget:self action:@selector(handleSwipe:)];  
    [self.view addGestureRecognizer:recognizer];  
    [recognizer release];  
}  

/** 
 *  平移手勢響應事件 
 * 
 *  @param swipe swipe description 
 */  
- (void)handleSwipe:(UIPanGestureRecognizer *)swipe  
{  

    if (swipe.state == UIGestureRecognizerStateChanged) {  
        [self commitTranslation:[swipe translationInView:self.view]];  
    }  
}  


/** 
 *   判斷手勢方向 
 * 
 *  @param translation translation description 
 */  
- (void)commitTranslation:(CGPoint)translation  
{  

    CGFloat absX = fabs(translation.x);  
    CGFloat absY = fabs(translation.y);  

    // 設置滑動有效距離  
    if (MAX(absX, absY) < 10)  
        return;  


    if (absX > absY ) {  

        if (translation.x<0) {  

            //向左滑動  
        }else{  

            //向右滑動  
        }  

    } else if (absY > absX) {  
        if (translation.y<0) {  

            //向上滑動  
        }else{  

            //向下滑動  
        }  
    }  


}