WPF根据窗口内容自动调整窗口大小

在创建WPF窗体时，如果固定窗体宽高，在要显示内容很少或者很多的情况下，窗体布局就会显得不怎么好看。如果能根据窗口内容自动调整窗口大小会显得比较适宜，这时我们需要用到Window.SizeToContent属性。 

下面以固定宽度，高度可变为例，新建一个WPF窗体应用程序SizeToContentDemo。

1、窗体xaml

<Window x:Class="SizeToContentDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:SizeToContentDemo"
        mc:Ignorable="d"
        WindowState="Normal" WindowStartupLocation="CenterScreen" ResizeMode="NoResize"
        Title="SizeToContentDemo" Window.SizeToContent="Height" Width="500" Loaded="Window_Loaded">
    <Grid x:Name="Grid_Content" Margin="20,20,20,30">
        <Grid.RowDefinitions>
            <RowDefinition Height="auto"/>
            <RowDefinition Height="32"/>
        </Grid.RowDefinitions>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="提示" HorizontalAlignment="Center" VerticalAlignment="Top" Foreground="#333" FontSize="18" FontWeight="Black" />
            <TextBlock x:Name="ContentText" Text="提示内容" FontSize="12" Foreground="#666666" Margin="30,20,30,30" HorizontalAlignment="Center"
                           TextAlignment="Center" VerticalAlignment="Top" TextWrapping="Wrap"/>
        </StackPanel>
        <UniformGrid Rows="1" Width="300" Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Bottom">
            <Button x:Name="SureBtn" Content="确定" Height="32" VerticalAlignment="Center" Margin="0,0,8,0" Click="SureBtn_Click"/>
            <Button x:Name="CancelBtn" Content="取消" Height="32" VerticalAlignment="Center" Margin="8,0,0,0"/>
        </UniformGrid>
    </Grid>
</Window>

2、交互逻辑

using System;
using System.Windows;

namespace SizeToContentDemo
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            this.ContentText.Text = "是否关闭此窗体？";
            //this.ContentText.Text = "这是一个非常严重的误操作，继续运行将产生未知错误!" + "\r\n" + "要获取详细信息请与管理员联系。" + "\r\n" + "错误码：001" + "\r\n" + "是否关闭该程序？";
            this.Height = Grid_Content.ActualHeight;
        }

        private void SureBtn_Click(object sender, RoutedEventArgs e)
        {
            this.Close();
        }
    }
}

3、运行效果