阅读导航：

• 一、先看效果
• 二、本文背景
• 三、代码实现
• 四、文章参考
• 五、代码下载

一、先看效果

二、本文背景

YouTube  Design com WPF 大神处习得，常用的遮罩对话框实现，使用的开源 C# WPF控件库 MaterialDesignInXAML ，本站曾有介绍：开源C# WPF控件库《MaterialDesignInXAML》。

三、代码实现

3.1 添加Nuget库

站长使用.Net Core 3.1创建的WPF工程，创建“ScreenOverlayMessage”解决方案后，需要添加两个Nuget库：MaterialDesignThemes和MaterialDesignColors，上图的效果是使用该控件库实现的，非常强大。

3.2 工程结构

不需要截图，只修改了两个文件，App.xaml添加MD控件4个样式文件，MainWindow主窗口实现效果。

3.3 App.xaml引入MD控件样式

<Application x:Class="DropDownMenu.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:DropDownMenu"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Light.xaml"/>
                <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Defaults.xaml"/>
                <ResourceDictionary Source="pack://application:,,,/MaterialDesignColors;component/Themes/Recommended/Primary/MaterialDesignColor.Blue.xaml"/>
                <ResourceDictionary Source="pack://application:,,,/MaterialDesignColors;component/Themes/Recommended/Accent/MaterialDesignColor.Indigo.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

3.4 主窗体

MainWindow.xaml，整体布局，看上图加上下面的界面代码，添加界面左上角logo图标、左侧导航菜单等，下面即是全部代码。

<Window x:Class="ScreenOverlayMessage.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:ScreenOverlayMessage"
        mc:Ignorable="d"
        xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes" MouseDown="Window_MouseDown"
        Title="MainWindow" Height="576" Width="1024" ResizeMode="NoResize" WindowStartupLocation="CenterScreen" WindowStyle="None" Background="#FF423A3A">
    <Grid>
        <materialDesign:DialogHost BorderBrush="{DynamicResource MaterialDesignDivider}">
            <materialDesign:DialogHost.DialogContent>
                <Grid Width="300" Height="150" HorizontalAlignment="Center">
                    <StackPanel Orientation="Horizontal" Margin="15">
                        <materialDesign:PackIcon Kind="Folder" Foreground="{StaticResource PrimaryHueMidBrush}" Width="50" Height="50"/>
                        <TextBlock Foreground="Gray" Width="200" Margin="15 5" TextWrapping="Wrap">
                            允许应用程序访问您计算机上的照片、媒体和文件？
                        </TextBlock>
                    </StackPanel>
                    <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" VerticalAlignment="Bottom" Margin="15">
                        <Button Command="{x:Static materialDesign:DialogHost.CloseDialogCommand}" Style="{DynamicResource MaterialDesignFlatButton}" Margin="4" VerticalAlignment="Center">
                            拒绝
                        </Button>
                        <Button Command="{x:Static materialDesign:DialogHost.CloseDialogCommand}" Style="{DynamicResource MaterialDesignFlatButton}" Margin="4" VerticalAlignment="Center">
                            允许
                        </Button>
                    </StackPanel>
                </Grid>
            </materialDesign:DialogHost.DialogContent>
            <Grid>
                <StackPanel Width="200" HorizontalAlignment="Left" Background="#FF472076">
                    <Grid Height="150" Background="White">
                        <Image Source="https://img.dotnet9.com/logo.png"/>
                    </Grid>
                    <Button Style="{StaticResource MaterialDesignFlatButton}" Command="{x:Static materialDesign:DialogHost.OpenDialogCommand}">
                        <StackPanel Orientation="Horizontal" Height="30">
                            <materialDesign:PackIcon Kind="PhotoAlbum" Width="20" Height="20" VerticalAlignment="Center"/>
                            <TextBlock Text="照片" Margin="20 0" FontSize="15" VerticalAlignment="Center"/>
                        </StackPanel>
                    </Button>
                    <Button Style="{StaticResource MaterialDesignFlatButton}" Command="{x:Static materialDesign:DialogHost.OpenDialogCommand}">
                        <StackPanel Orientation="Horizontal" Height="30">
                            <materialDesign:PackIcon Kind="Music" Width="20" Height="20" VerticalAlignment="Center"/>
                            <TextBlock Text="音乐" Margin="20 0" FontSize="15" VerticalAlignment="Center"/>
                        </StackPanel>
                    </Button>
                </StackPanel>
            </Grid>
        </materialDesign:DialogHost>
    </Grid>
</Window>

重点讲解：

• materialDesign:DialogHost：设置遮罩对话框覆盖的地方，即弹出遮罩对话框后，背后有阴影的位置。
• materialDesign:DialogHost.DialogContent：对话框内容，即弹出的对话框配置

后台有个拖动窗体代码：

private void Window_MouseDown(object sender, MouseButtonEventArgs e)
{
    DragMove();
}

四、文章参考

建议直接打开大神视频学习，他的YouTube上还有很多代码视频哦，参考：
参考视频： Design com WPF： https://www.youtube.com/watch?v=Dwi9o3K73XM

五、代码下载

文章中代码已经全部贴出。