// CGAffineTransformTranslate 位置移動,改變frame中original的坐标點,但是center值沒變,是以如果要發生形變的話,不能在此基礎上改變,這時必須通過改變center的值來實作位置移動
// CGAffineTransformScale 按比例改變frame中size的大小
// CGAffineTransformRotate 旋轉
// C和OC語言裡,case中不能定義變量
- (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中形變預設的錨點是中心點,對應的屬性是center,但是通過 CGAffineTransformTranslate 屬性來實作 位置移動,是改變 frame 中 original 的坐标點 , 但是 center 值沒變(其實應該是需要改變的,但是不知道蘋果為啥沒改變,這個有待考究),是以如果要發生形變(放大,縮小,旋轉)的話,不能在此基礎上改變,這時必須通過改變 center 的值來實作位置移動