ios 如何设置 UIView 的原点参考？
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How to set a UIView's origin reference?
提问by Daniel
I am creating a UIImageView and adding it in a loop to my view, I set the initial frame to 0,0,1,47 and each passage of the loop I change the center of the image view to space them out.
我正在创建一个 UIImageView 并将其循环添加到我的视图中，我将初始帧设置为 0,0,1,47 并且循环的每个段落我更改图像视图的中心以将它们隔开。
I am always using 0 as the origin.y
我总是使用 0 作为 origin.y
The problem is the origin reference is in the centre of the image view, assuming we was in interface builder, this is equivalent to the image below.
问题是原点引用在图像视图的中心，假设我们在界面构建器中，这相当于下图。
How can I change the reference point in code ?
如何更改代码中的参考点？
回答by Tricertops
After reading these answers and your comments I'm not really sure what is your point.
阅读这些答案和您的评论后，我不确定您的观点是什么。
With UIViewyou can set position by 2 ways:
随着UIView您可以通过2种方式设置的位置：
center– It definitely says it is the center.frame.origin– Top left corner, can't be set directly.
center- 它肯定说它是中心。frame.origin– 左上角，不能直接设置。
If you want the bottom left corner to be at x=300, y=300 you can just do this:
如果您希望左下角位于 x=300, y=300 处，您可以这样做：
UIView *view = ...
CGRect frame = view.frame;
frame.origin.x = 300 - frame.size.width;
frame.origin.y = 300 - frame.size.height;
view.frame = frame;
But if you go one level deeper to magical world of CALayers(don' forget to import QuartzCore), you are more powerful.
但是如果你更深入一层CALayers（不要忘记导入 QuartzCore）的魔法世界，你就会更强大。
CALayerhas these:
CALayer有这些：
position– You see, it don't explicitely says 'center', so it may not be center!anchorPoint–CGPointwith values in range 0..1 (including) that specifies point insidethe view. Default is x=0.5, y=0.5 which means 'center' (and-[UIView center]assumes this value). You may set it to any other value and thepositionproperty will be applied to that point.
position– 你看，它没有明确地说“中心”，所以它可能不是中心！anchorPoint–CGPoint值在 0..1（包括）范围内，指定视图内的点。默认值为 x=0.5，y=0.5，这意味着“中心”（并-[UIView center]假定此值）。您可以将其设置为任何其他值，并且该position属性将应用于该点。
Example time:
示例时间：
- You have a view with size 100x100
view.layer.anchorPoint = CGPointMake(1, 1);view.layer.position = CGPointMake(300, 300);- Top left corner of the view is at x=200, y=200 and its bottom right corner is at x=300, y=300.
- 您有一个大小为 100x100 的视图
view.layer.anchorPoint = CGPointMake(1, 1);view.layer.position = CGPointMake(300, 300);- 视图的左上角在 x=200, y=200 处，右下角在 x=300, y=300 处。
Note:When you rotate the layer/view it will be rotated around the anchorPoint, that is the center by default.
注意：当您旋转图层/视图时，它将围绕 旋转anchorPoint，这是默认情况下的中心。
Bu since you just ask HOWto do specific thing and not WHATyou want to achieve, I can't help you any further now.
卜，因为你刚才问如何做具体的事情，而不是什么你想达到的，我不能再现在帮你任何。
回答by Phillip Mills
The object's frame includes its position in its superview. You can change it with something like:
对象的框架包括其在其父视图中的位置。您可以使用以下内容更改它：
CGRect frame = self.imageView.frame;
frame.origin.y = 0.0f;
self.imageView.frame = frame;
回答by jmstone617
If I am understanding you correctly, you need to set the frame of the image view you are interested in moving. This can be done in the simple case like this:
如果我理解正确，您需要设置您有兴趣移动的图像视图的框架。这可以在这样的简单情况下完成：
_theImageView.frame = CGRectMake(x, y, width, height);
Obviously you need to set x, y, width, and height yourself. Please also be aware that a view's frame is in reference to its parent view. So, if you have a view that is in the top left corner (x = 0, y = 0), and is 320 points wide and 400 points tall, and you set the frame of the image view to be (10, 50, 100, 50) and then add it as a subview of the previous view, it will sit at x = 10, y = 50 of the parent view's coordinate space, even though the bounds of the image view are x = 0, y = 0. Bounds are in reference to the view itself, frame is in reference to the parent.
显然，您需要自己设置 x、y、宽度和高度。另请注意，视图的框架是参考其父视图。因此，如果您的视图位于左上角 (x = 0, y = 0)，宽 320 点，高 400 点，并且您将图像视图的框架设置为 (10, 50, 100, 50) 然后将其添加为上一个视图的子视图，它将位于父视图坐标空间的 x = 10, y = 50，即使图像视图的边界是 x = 0, y = 0 .bounds 是参考视图本身，frame 是参考父级的。
So, in your scenario, your code might look something like the following:
因此，在您的场景中，您的代码可能如下所示：
CGRect currentFrame = _theImageView.frame;
currentFrame.origin.x = 0;
currentFrame.origin.y = 0;
_theImageView.frame = currentFrame;
[_parentView addSubview:_theImageView];
Alternatively, you can say:
或者，你可以说：
CGRect currentFrame = _theImageView.frame;
_theImageView.frame = CGRectMake(0, 0, currentFrame.size.width, currentFrame.size.height);
[_parentView addSubview:_theImageView];
Either approach will set the image view to the top left of the parent you add it to.
任何一种方法都会将图像视图设置到您添加到的父级的左上角。
