在UIView的邊界上使用碰撞

Question

我有一個ImageView，圍繞UIView移動，是否有可能檢測ImageView和視圖的自我碰撞？例如，ImageView打到我希望它運行一個動作的視圖的一側。 -(void)restart {} 如果這是可能的，你可以檢測到它與哪邊碰撞？

Answer 1

您可以創建自定義UIImageVIew並實現方法touchBegan和touchMoved（不要忘記在init方法中添加[self setUserInteractionEnabled:YES]）。然後設置要互動與矩形：

customImageView.interactRect = myView.frame; 

而在你customImageView您可以添加類似：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ 
    UITouch *touch = [[event allTouches] anyObject]; 
    lastPosition = [touch locationInView: self.superview]; 
} 

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

    UITouch *touch = [[event allTouches] anyObject]; 
    CGPoint position = [touch locationInView:self.superview]; 
    CGRect currentFrame = self.frame; 
    currentFrame.origin = CGPointMake(currentFrame.origin.x + position.x - lastPosition.x, currentFrame.origin.y + position.y - lastPosition.y); 

    if (CGRectIntersectsRect(currentFrame, interactRect) && !CGRectIntersectsRect(self.frame, interactRect)) 
    { 
     NSLog(@"I'm in for the first time"); 
     if(self.frame.origin.x + self.frame.size.width <= interactRect.origin.x && currentFrame.origin.x + currentFrame.size.width > interactRect.origin.x) 
     { 
      NSLog(@"Coming from the left"); 
     } 
     if(self.frame.origin.x >= interactRect.origin.x + interactRect.size.width && currentFrame.origin.x < interactRect.origin.x + interactRect.size.width) 
     { 
      NSLog(@"Coming from the right"); 
     } 
    } 
    self.frame = currentFrame; 
    lastPosition = position; 
}