iOS缩放、旋转UIButton

在练习缩放旋转UIButton控件时，出现点击控件x,y同时增加或者减一定像素，经过查找是xcode5开启了Auto Layout.

放大缩小的代码

- (IBAction)btnScale:(UIButton *)sender {
    //动画开始，设置执行时间
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1];
    int tag = [sender tag];
    float scale = tag == 8? 1.2: 0.8;
    //CGAffineTransform _transform = _btn.transform;
    _btn.transform = CGAffineTransformScale(_btn.transform, scale, scale);
    //_transform = _btn.transform;
    //提交动画
    [UIView commitAnimations];
}

 左右旋转的代码

- (IBAction)btnRotate:(UIButton *)sender {
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1];
    int tag = [sender tag];
    int rotate = tag == 7? 1: -1;
    _btn.transform = CGAffineTransformRotate(_btn.transform, M_PI_4*rotate);
    //int rotate = tag==7? 1: -1;
    //_btn.transform = CGAffineTransformRotate(_btn.transform, M_PI_4*rotate);
    [UIView commitAnimations];
}

 还原控件的操作

- (IBAction)btnReset:(UIButton *)sender {
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:1];
    sender.transform = CGAffineTransformIdentity;
    [UIView commitAnimations];
}