transform的使用

1.平移，缩放，旋转

//平移
self.tempView.transform = CGAffineTransformMakeTranslation(-100, 100);
//缩放
self.tempView.transform = CGAffineTransformMakeScale(0.5, 0.5);
//旋转
self.tempView.transform = CGAffineTransformMakeRotation(-M_PI_4);

2.除此之外还可以叠加动画效果，三种或者两种合起来

//平移+缩放+旋转
CGAffineTransform translation = CGAffineTransformMakeTranslation(-100, 100);
CGAffineTransform scaleTranslation = CGAffineTransformScale(translation, 0.5, 0.5);
CGAffineTransform rotateScaleTranslation = CGAffineTransformRotate(scaleTranslation, M_PI_2);
 self.tempView.transform = rotateScaleTranslation;

3.清空以前的效果

// 清空transform，以前的平移、缩放、旋转都会消失
[UIView animateWithDuration:2.0 animations:^{
        self.tempView.transform = CGAffineTransformIdentity;
        
}];