在UIView的邊界上使用碰撞

Question

我有一個在UIView周圍移動的ImageView，是否可以檢測到ImageView及其視圖自身的碰撞？ 例如，ImageView擊中了我希望它執行操作的視圖的側面。 -(void)restart {}如果可能，您可以檢測到它與哪一側發生了碰撞？

Answer 1

您可以創建一個自定義UIImageVIew並實現touchBegan和touchMoved方法（不要忘記在init方法中添加[self setUserInteractionEnabled:YES] ）。 然后設置要與之交互的矩形：

customImageView.interactRect = myView.frame;

在您的customImageView中，您可以添加以下內容：

-(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;
}