iPhone编程：UIImageView和动画的冲突检测

Question

我在ViewDid中有一个动画，如下所示

-(void)viewDidAppear:(BOOL)animated
{
    for (int i = 0; i < 100; i++) {

        p = arc4random_uniform(320)%4+1; //global integer

        CGRect startFrame = CGRectMake(p*50, -50, 50, 50);
        CGRect endFrame   = CGRectMake(p*50, CGRectGetHeight(self.view.bounds) + 50,
                                       50,
                                       50);

        animatedView = [[UIView alloc] initWithFrame:startFrame];
        animatedView.backgroundColor = [UIColor redColor];

        [self.view addSubview:animatedView];

        [UIView animateWithDuration:2.f
                              delay:i * 0.5f
                            options:UIViewAnimationCurveLinear
                         animations:^{
                             animatedView.frame = endFrame;
                         } completion:^(BOOL finished) {
                             [animatedView removeFromSuperview];
                         }];
    }
}

它只是从屏幕顶部创建小正方形，然后移动到底部。我还有一个UIImageView，它由x轴上的加速计控制。目标不是接触动画对象。就像一个简单的比赛游戏。然而，我无法找到如何检测imageView和动画之间的冲突？

Answer 1

此测试中存在问题：如果（CGRectIntersectsRect（theView.frame，yourImageView.frame）必须检查视图的presentationLayer：

CGRect movingFrame = [[theImage.layer presentationLayer] frame];
    if (CGRectIntersectsRect(movingFrame, panier.frame)) {           
        // the image collided            
    }

Answer 2

首先你需要在一个数组中保存所有的动画视图对象来检查与图像视图的冲突

NSMutableArray animatedViews;

然后在视图中进行初始化

animatedViews = [[NSMutableArray alloc] init];

然后“更改代码”视图将出现并添加一行

[self.view addSubview:animatedView];
[animatedViews addObject:animatedView];

然后创建一个冲突检查函数

-(void) checkCollision: (NSTimer *) theTimer{
    for(int i = 0; i < [animatedViews count]; i++) {
        UIView *theView = [animatedViews objectAtIndex:index];
        if (CGRectIntersectsRect(theView.frame, yourImageView.frame) {
           // the image collided
           // stop the timer and do your work here
        }
    }
}

然后在视图中添加这一行来调度定时器，每隔半秒钟调用函数以检查碰撞

[NSTimer scheduledTimerWithTimeInterval: 0.5  
                             target: self  
                           selector: @selector(checkCollision:)  
                           userInfo: nil  
                            repeats: YES];