为什么在WPF的CustomTemplate中使用网格? [英] Why use Grid in a CustomTemplate in WPF?

问题描述

我试图创建一些我WPF的ControlTemplates，但是有些东西我不知道.

为什么有时我必须使用< Grid>在CustomTemplate定义中有时不是?

当我创建一个仅包含矩形"的ControlTemplate时，将使用以下代码:

I have tried to create some ControlTemplates I WPF, but there is something I can''t figure out.

Why do I sometimes have to use <Grid> in the CustomTemplate definition and sometimes not?

When I create a ControlTemplate that just contains the "Rectangle", I use this code:

<Style TargetType="{x:Type Button}">
 <Setter Property="Background">
  . . .
 <Setter Property="Template">
  <Setter.Value>
   <ControlTemplate x:Key="ButtonTemplate">
     <Rectangle Fill="{TemplateBinding Property=Background}" />
   </ControlTemplate>
  </Setter.Value>
 </Setter>
</Style>

当我不想在模板中包含ContentPresenter时，必须将代码括在< Grid>中. -像这样:

When I wan''t to include ContentPresenter in the template I have to enclose the code in <Grid> - like this:

<Style TargetType="{x:Type Button}">
 <Setter Property="Background">
  ...
 <Setter Property=&quot;Template&quot;&gt;

  <Setter.Value>
   <ControlTemplate TargetType="{x:Type Button}">
    <Grid>
     <Rectangle Fill="{TemplateBinding Property=Background}" />
     <ContentPresenter Content="{TemplateBinding Property=ContentControl.Content}"                                                VerticalAlignment="Center"

      HorizontalAlignment="Center" />
    </Grid>
   <ControlTemplate>
  <Setter.Value>
 </Setter>
</Style>

Stig Helmer

Stig Helmer

推荐答案

如果我正确理解了您的问题，原因是Button源自ContentControl，ContentControl只能包含1个项目.

不过，它不一定必须是网格，它可以很容易地是StackPanel或可以容纳多个项目的任何控件.

If I have understood your question correctly, the reason is that Button descendss from ContentControl and ContentControl can only contain 1 item.

It doesn''t have to be a grid though, it could as easily be a StackPanel or any control that can hold more than one item.

好吧，我建议您使用一个边框而不是一个矩形.矩形只是一个形状，而边框是一个容器，因为它继承了Controls.Decorator类.
在此边框中，可以将ContentPresenter放置在其中，而无需网格来固定它.您不能对Rectangle进行相同的操作，因为它不能容纳元素.

因此，您可以像这样创建边框:

Well i would suggest you to use a Border instead of a Rectangle. Rectangle is just a shape but a Border is a container as it inherits the Controls.Decorator class.
In this a Border can place the ContentPresenter inside it without the need for a Grid to hold it. You cannot do the same with a Rectangle as it cannot hold elements.

So you can create a Border like this :

<ControlTemplate TargetType="{x:Type Button}">
<border name="ButtonBorder" cornerradius="4" borderthickness="1">
   <contentpresenter content="{TemplateBinding Content}">
      VerticalAlignment="Center"
      HorizontalAlignment="Center"/>
</contentpresenter></border>

您可以在我的博客中查看:圆形按钮 [ ^ ].

我想补充的一件事是，矩形"将仅为您的Button提供一个形状，而ContentPresenter将显示Button的实际内容.
例如:

You can check it out here in my blog : Round-Edged Button[^].

One more thing i would like to add is that, the Rectangle will only give a shape to your Button but the ContentPresenter will display the actual content of the Button.
For Ex:

<Button Name="myButton" HorizontalAlignment="Center">
   <Button.Content>
       <Image Source="Winter.jpg"/>
   </Button.Content>
</Button>

如果要在按钮中显示此图像，则在模板中，必须设置

If you want to display this Image in your Button, then in Template, you have to set the

<contentpresenter content="{TemplateBinding Content}" />

希望我能解决您的疑问.

I hope i was able to clear your doubt.

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