这完全是iPhone的庸俗。我正在开发一个库,但已将我的问题缩小到非常简单的代码。这段代码的作用是创建一个50x50的视图,应用几度的旋转变换,然后将帧向下移动几次。结果是50x50视图现在看起来要大得多。
以下是代码:
// a simple 50x50 view
UIView *redThing = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 50, 50)];
redThing.backgroundColor = [UIColor redColor];
[self.view addSubview:redThing];
// rotate a small amount (as long as it's not 90 or 180, etc.)
redThing.transform = CGAffineTransformRotate(redThing.transform, 0.1234);
// move the view down 2 pixels
CGRect newFrame = CGRectMake(redThing.frame.origin.x, redThing.frame.origin.y + 2, redThing.frame.size.width, redThing.frame.size.height);
redThing.frame = newFrame;
// move the view down another 2 pixels
newFrame = CGRectMake(redThing.frame.origin.x, redThing.frame.origin.y + 2, redThing.frame.size.width, redThing.frame.size.height);
redThing.frame = newFrame;
// move the view down another 2 pixels
newFrame = CGRectMake(redThing.frame.origin.x, redThing.frame.origin.y + 2, redThing.frame.size.width, redThing.frame.size.height);
redThing.frame = newFrame;
// move the view down another 2 pixels
newFrame = CGRectMake(redThing.frame.origin.x, redThing.frame.origin.y + 2, redThing.frame.size.width, redThing.frame.size.height);
redThing.frame = newFrame;
那么,到底是怎么回事?现在,如果我通过应用平移变换来移动视图,它就可以正常工作。但这不是我想做的事情,应该无论如何都要工作。
有什么想法吗?
答案 0 :(得分:15)
来自UIView文档:
如果还设置了transform属性,请改用bounds和center属性;否则,动画对帧属性的更改不会正确反映视图的实际位置。
警告:如果transform属性不是identity变换,则此属性的值是未定义的,因此应该被忽略。
换句话说,当设置frame
时,我会对transform
属性保持警惕。