Animation 如何移动UIImageView？

交易如下： 我在viewDidLoad中编码UIImageView，我希望它在按下按钮**的情况下向下移动，而不会像我一样创建其他子视图

这是密码

-（无效）viewDidLoad{

[超级视图下载]

banetteImage=[UIImage ImageName:@“myBanette.png”]

[NSTimer scheduledTimerWithTimeInterval:2.5目标：自选择器：@selector（按钮按下：）用户信息：无重复：否]

[self.view addSubview:banetteView];

}

-（无效）按下按钮{

double speed = 1 / round(random() % 100) + 1.0;

[UIView beginAnimations:nil context:banetteView];
[UIView setAnimationDuration: 2*speed ];

banetteView.frame = CGRectMake(100, -2, 568, 790);
banetteView.opaque = NO;

UIImageView *banetteView = [[UIImageView alloc] initWithImage:banetteImage];
banetteView2.frame = CGRectMake(100, -740, 568, 790);
banetteView.opaque = NO;
banetteView.hidden = YES;
[self.view addSubview:banetteView];

// set a stop callback so we can cleanup the banette when it reaches the
// end of its animation
[UIView setAnimationDidStopSelector:@selector(onAnimationComplete:finished:context:)];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];

}

-（void）onAnimationComplete:（NSString*）animationID finished:（NSNumber*）finished context:（void*）context{

---

}

通过修改此代码，我发现

double speed = 1 / round(random() % 100) + 1.0;

[UIView beginAnimations:nil context:banetteView];
[UIView setAnimationDuration: 2*speed ];

banetteView.frame = CGRectMake(100, -2, 568, 790);
banetteView.opaque = NO;

UIImageView *banetteView = [[UIImageView alloc] initWithImage:banetteImage];
banetteView2.frame = CGRectMake(100, -740, 568, 790);
banetteView.opaque = NO;
banetteView.hidden = YES;
[self.view addSubview:banetteView];

// set a stop callback so we can cleanup the banette when it reaches the
// end of its animation
[UIView setAnimationDidStopSelector:@selector(onAnimationComplete:finished:context:)];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];

UIImageView *banetteView = context;


double speed = 1 / round(random() % 100) + 1.0;
banetteView.frame = CGRectMake(100, -2, 568, 790);
banetteView2.opaque = NO;
[self.view addSubview:banetteView2];

[UIView beginAnimations:nil context:banetteView];
[UIView setAnimationDuration: 2*speed ];


[banetteView release];