// CGAffineTransformTranslate 位置移动,改变frame中original的坐标点,但是center值没变,因此如果要发生形变的话,不能在此基础上改变,这时必须通过改变center的值来实现位置移动
// CGAffineTransformScale 按比例改变frame中size的大小
// CGAffineTransformRotate 旋转
// C和OC语言里,case中不能定义变量
- (IBAction)actionEvent:(UIButton *)sender {
CGAffineTransform transform;
CGPoint center;
switch (sender.tag) {
case 0:
center = _imageView.center;
center.y -= 10;
// NSLog(@"%@",NSStringFromCGPoint(_imageView.center));
// NSLog(@"%@",NSStringFromCGPoint(_imageView.frame.origin));
// transform = CGAffineTransformTranslate(_imageView.transform, 10, 10);
// _imageView.transform = transform;
// NSLog(@"%@",NSStringFromCGPoint(_imageView.frame.origin));
// NSLog(@"%@",NSStringFromCGPoint(_imageView.center));
break;
case 1:
center = _imageView.center;
center.y += 10;
break;
case 2:
center = _imageView.center;
center.x -= 10;
break;
case 3:
center = _imageView.center;
center.x += 10;
break;
case 4:
transform = CGAffineTransformScale(_imageView.transform, 1.2, 1.2);
break;
case 5:
transform = CGAffineTransformScale(_imageView.transform, 1/1.2, 1/1.2);
break;
case 6:
transform = CGAffineTransformRotate(_imageView.transform, M_PI_4);
break;
case 7:
transform = CGAffineTransformRotate(_imageView.transform, -M_PI_4);
break;
default:
break;
}
if (sender.tag < 4) {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.0];
_imageView.center = center;
[UIView commitAnimations];
} else {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:1.0];
_imageView.transform = transform;
[UIView commitAnimations];
}
}
IOS中形变默认的锚点是中心点,对应的属性是center,但是通过 CGAffineTransformTranslate 属性来实现 位置移动,是改变 frame 中 original 的坐标点 , 但是 center 值没变(其实应该是需要改变的,但是不知道苹果为啥没改变,这个有待考究),因此如果要发生形变(放大,缩小,旋转)的话,不能在此基础上改变,这时必须通过改变 center 的值来实现位置移动