iOS小效果（2）按钮控制图片的放大缩小

按钮控制图片的放大缩小

：

- (IBAction)bigger:(id)sender{    [UIView beginAnimations:nil context:nil];    [UIView setAnimationDuration:1.0];    _btn.transform=CGAffineTransformScale(_btn.transform, 1.2, 1.2);    [UIView commitAnimations];}- (IBAction)smaller:(id)sender{    [UIView beginAnimations:nil context:nil];    [UIView setAnimationDuration:1.0];    _btn.transform=CGAffineTransformScale(_btn.transform, 0.8, 0.8);    [UIView commitAnimations];}