Vb.net - 设置控件边距值
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/4837400/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Vb.net - Setting a controls margin value
提问by Kenny Bones
So, I'm adding a label programatically and I'm in need of altering the top margin a little bit to the value 8. I can't do that the obvious way, so what's wrong with my thinking?
所以，我正在以编程方式添加一个标签，我需要将顶部边距稍微更改为值 8。我不能以明显的方式做到这一点，所以我的想法有什么问题？
Dim LabelAdapter As New Label
LabelAdapter.text = "Adapter"
LabelAdapter.Margin.Top = 8
This gives me the error "Expression is a value and therefore cannot be the target of an assignment".
这给了我错误“表达式是一个值，因此不能成为赋值的目标”。
回答by Konrad Rudolph
Label.Marginreturns a Paddingobject.
Label.Margin返回一个Padding对象。
Since Paddingis a structure, it will actually return a copy. You are changing the Topvalue of that copy, not of the actual control's margin. Since that would have no noticeable effect, VB correctly prevents it.
由于Padding是一个结构，它实际上会返回一个副本。您正在更改该Top副本的值，而不是实际控制的边距。由于这不会有明显的影响，VB 正确地阻止了它。
You need to assign a whole new margin. In fact, the Marginproperty (or rather, the Paddingclass) is arguably broken since it doesn't allow an easy way to change the individual values.
您需要分配一个全新的边距。事实上，Margin属性（或者更确切地说，Padding类）可以说是损坏的，因为它不允许简单的方法来更改单个值。
Unfortunately, we just have to live with it. So to change just the Topvalue, we need to write:
不幸的是，我们只能忍受它。因此，要仅更改Top值，我们需要编写：
Dim old As Padding = LabelAdapter.Margin
LabelAdapter.Margin = New Padding(old.Left, 8, old.Right, old.Bottom)
Weird, huh?
很奇怪吧？
