WPF自定义一个MessageBox

<Window x:Class="AgileToDo.UMessageBox"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="UMessageBox" Height="130" Width="280" WindowStyle="None"   Background="{x:Null}"  
        ResizeMode="NoResize"  x:Name="main"
        AllowsTransparency="True" WindowStartupLocation="CenterScreen">
    <Window.Triggers>
        <EventTrigger RoutedEvent="Window.Loaded" >
            <BeginStoryboard>
                <Storyboard Name="sbOpShow">
                    <DoubleAnimation
                    Storyboard.TargetName="main" 
                    Storyboard.TargetProperty="Opacity" 
                    From="0" To="0.8" Duration="0:0:0.15"/>
                </Storyboard>
            </BeginStoryboard>
        </EventTrigger>
    </Window.Triggers>
    <Window.Resources>
    </Window.Resources>
    <Border Background="#F03A3A3A" Opacity="1" CornerRadius="3">
            <Canvas>
                
            <Border Canvas.Top="0" Height="25" Width="{Binding ElementName=main, Path=Width,UpdateSourceTrigger=PropertyChanged}" 
                    BorderThickness="0,0,0,1" BorderBrush="#FFEFE2E2">
                <TextBlock x:Name="lblTitle" Text="test" HorizontalAlignment="Left" 
                           Foreground="#FFCBBEBE" FontSize="14"
                           VerticalAlignment="Center" Margin="5"/>
            </Border>
            <TextBlock x:Name="lblMsg"
                       Foreground="White" FontSize="14" 
                       TextWrapping="Wrap" Text="test"
                       HorizontalAlignment="Center" Canvas.Left="20"
                       Canvas.Top="50" 
                       />
            <Border BorderBrush="#FF60C1C1" BorderThickness="0.5" Height="22" 
                    Canvas.Bottom="10" Canvas.Right="85" MouseLeftButtonDown="Yes_MouseLeftButtonDown"
                 Name="border1" Width="49" Background="#FFC7C7C7" CornerRadius="2">
                <TextBlock Text="YES"  HorizontalAlignment="Center" VerticalAlignment="Center"/>
            </Border>
            <Border BorderBrush="#FF60C1C1" BorderThickness="0.5" Height="22" 
                    Canvas.Bottom="10" Canvas.Right="30" MouseLeftButtonDown="No_MouseLeftButtonDown"
                Name="border2" Width="49" CornerRadius="2" Background="#FFC7C7D1">
                <TextBlock Text="NO"  HorizontalAlignment="Center" VerticalAlignment="Center"/>
            </Border>
        </Canvas>
    </Border>
</Window>

using System.Windows;
using System.Windows.Input;
using System.Windows.Media.Animation;

namespace AgileToDo
{
    /// <summary>
    /// UMessageBox.xaml 的交互逻辑
    /// </summary>
    public partial class UMessageBox : Window
    {
        /// <summary>
        /// 禁止在外部实例化
        /// </summary>
        private UMessageBox()
        {
            InitializeComponent();
        }
        public new string Title
        {
            get { return this.lblTitle.Text; }
            set { this.lblTitle.Text = value; }
        }
        public string Message
        {
            get { return this.lblMsg.Text; }
            set { this.lblMsg.Text = value; }
        }
        /// <summary>
        /// 静态方法 模拟MESSAGEBOX.Show方法
        /// </summary>
        /// <param name="title">标题</param>
        /// <param name="msg">消息</param>
        /// <returns></returns>
        public static bool? Show(string title,string msg)
        {
            var msgBox = new UMessageBox();
            msgBox.Title = title;
            msgBox.Message = msg;
            return msgBox.ShowDialog();
        }
        private void Yes_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            this.DialogResult = true;
            this.Close();
        }

        private void No_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            this.DialogResult = false;
            this.Close();
        }
    }
}