在UIView的边界上使用碰撞

Question

我有一个ImageView，围绕UIView移动，是否有可能检测ImageView和视图的自我碰撞？例如，ImageView打到我希望它运行一个动作的视图的一侧。 -(void)restart {} 如果这是可能的，你可以检测到它与哪边碰撞？

Answer 1

您可以创建自定义UIImageVIew并实现方法touchBegan和touchMoved（不要忘记在init方法中添加[self setUserInteractionEnabled:YES]）。然后设置要互动与矩形：

customImageView.interactRect = myView.frame; 

而在你customImageView您可以添加类似：

-(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; 
}