图片的放大缩小

-(void)createButtons
{
        for (int i = 0; i < 9; i++)
  {
    UIButton *button = [[UIButton alloc]init];
    button.frame = CGRectMake(60 + (i % 3) * 100, 100 + (i / 3) * 100, 100, 100);
    NSString *imageName = [NSString stringWithFormat:@"2_%d.jpg",i + 1];
    //设置背景图片
    [button setBackgroundImage:[UIImage imageNamed:imageName] forState:UIControlStateNormal];
    //设置高亮状态的背景图片
    [button setBackgroundImage:[UIImage imageNamed:imageName] forState:UIControlStateHighlighted];
    //添加点击事件
    [button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];
    
    }
 }

//把点击的button放到最表层
[self.view bringSubviewToFront:button];
//用来记住放大之前的位置和大小
static CGRect frame;
//如果是没有放大色状态
if (button.frame.size.width != self.view.frame.size.width) {
    //记录放大之前的位置和大小
    frame = button.frame;
    //开始动画块的标志,放大到全屏
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1];
    button.frame = self.view.bounds;
    [UIView commitAnimations];
}else
{
    //如果已经放大，缩小并放回原来的位置
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1];
    //把记录的原位置赋回去
    button.frame = frame;
    [UIView commitAnimations];
}