WPF 用户控件设计时间大小 [英] WPF UserControl Design Time Size

问题描述

在 WPF 中创建 UserControl 时，我发现给它一些任意的高度和宽度值很方便，以便我可以在 Visual Studio 设计器中查看我的更改.但是，当我运行控件时，我希望 Height 和 Width 是未定义的，以便控件将扩展以填充我放置它的任何容器. 如何在不必删除 Height 和 Width 值之前实现相同的功能建立我的控制?(或者在父容器中不使用 DockPanel.)

When creating a UserControl in WPF, I find it convenient to give it some arbitrary Height and Width values so that I can view my changes in the Visual Studio designer. When I run the control, however, I want the Height and Width to be undefined, so that the control will expand to fill whatever container I place it in. How can I acheive this same functionality without having to remove the Height and Width values before building my control? (Or without using DockPanel in the parent container.)

下面的代码演示了这个问题:

The following code demonstrates the problem:

<Window x:Class="ExampleApplication3.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:loc="clr-namespace:ExampleApplication3"
    Title="Example" Height="600" Width="600">
    <Grid Background="LightGray">
        <loc:UserControl1 />
    </Grid>
</Window>

UserControl1 的以下定义在设计时显示合理，但在运行时显示为固定大小:

The following definition of UserControl1 displays reasonably at design time but displays as a fixed size at run time:

<UserControl x:Class="ExampleApplication3.UserControl1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Height="300" Width="300">
    <Grid Background="LightCyan" />
</UserControl>

UserControl1 的以下定义在设计时显示为一个点，但在运行时扩展以填充父 Window1:

The following definition of UserControl1 displays as a dot at design time but expands to fill the parent Window1 at run time:

<UserControl x:Class="ExampleApplication3.UserControl1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid Background="LightCyan" />
</UserControl>

推荐答案

在 Visual Studio 中将 Width 和 Height 属性添加到您的 UserControl XAML，但在代码隐藏中插入此

In Visual Studio add the Width and Height attribute to your UserControl XAML, but in the code-behind insert this

public UserControl1()
{
    InitializeComponent();
    if (LicenseManager.UsageMode != LicenseUsageMode.Designtime)
    {
        this.Width = double.NaN; ;
        this.Height = double.NaN; ;
    }
}

这会检查控件是否在设计模式下运行.如果不是(即运行时)，它会将 Width 和 Height 设置为 NaN(不是数字)，这是您在 XAML 中删除 Width 和 Height 属性时设置的值.

This checks to see if the control is running in Design-mode. If not (i.e. runtime) it will set the Width and Height to NaN (Not a number) which is the value you set it to if you remove the Width and Height attributes in XAML.

因此，在设计时，您将拥有预设的宽度和高度(包括您是否将用户控件放入表单中)，并且在运行时它将根据其父容器停靠.

So at design-time you will have the preset width and height (including if you put the user control in a form) and at runtime it will dock depending on its parent container.

希望有所帮助.

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