iPhone开发：如何使用的NSTimer创建一个动画

问题描述

在我的应用我在这viewWillAppear中code。它只是动画从屏幕底部的顶部随机对象。问题是我需要检测碰撞，我学到到目前为止它是不可能在任何时候为动画检索坐标。所以我怎么能使用的NSTimer实现它？或者我应该使用的NSTimer？我无法弄清楚。任何线索将AP preciated。

   - （无效）viewWillAppear中：（BOOL）动画
{
    的for（int i = 0; I＆LT; 100;我++）{        p值= arc4random_uniform（320）％4 + 1;        的CGRect startFrame将= CGRectMake（P * 50，-50，50，50）;
        的CGRect endFrame = CGRectMake（P * 50，CGRectGetHeight（self.view.bounds）+50，
                                       50，
                                       50）;        animatedView = [[UIView的页头] initWithFrame：方法startFrame将];
        animatedView.backgroundColor =的UIColor redColor]        [self.view addSubview：animatedView];        [UIView的animateWithDuration：2.F
                              延迟：我* 0.5F
                            选项​​：UIViewAnimationCurveLinear
                         动画：^ {
                             animatedView.frame = endFrame;
                         }完成：^（BOOL完）{
                             [animatedView removeFromSuperview]
                         }];}
 

解决方案

您的语句：

seems incorrect did you check this?

It looks like you can use the CALayer's presentationLayer property to extract coordinates info during an animation:

CGRect movingFrame = [[yourView.layer presentationLayer] frame];

I will use this info to check time to time if there is a collision during the animation. So I will use the timer to check the collision status not for animating the views.

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