Wpf RoutedUICommand throws无法在此范围内注册重复名称“_Roots”如何解决此问题

Question

我在 xaml 块中创建了一个RoutedUICommand，如下所示，但无论我输入的是x:name值，它都会抛出：

  

无法在此范围内注册重复名称“_Roots”。

我是WPF的新手，但不是.net ......这看起来很奇怪......我错过了什么......提前谢谢。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using ImagingLibrary;
using System.Drawing;
using System.IO;
namespace TranshelperWpf
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {

        public MainWindow()
        {
            InitializeComponent();


        }



        private void RootsCommandBinding_Executed(object sender,
         ExecutedRoutedEventArgs e)
        {

        }

        private void RootsCommandBinding_CanExecute(object sender, 
        CanExecuteRoutedEventArgs e)
        {

        }

        private void MenuItem_Click(object sender, RoutedEventArgs e)
        {

        }

        private void UsageCommandBinding_CanExecute(object sender, 
        CanExecuteRoutedEventArgs e)
        {

        }

        private void UsageCommandBinding_Executed(object sender, 
           ExecutedRoutedEventArgs e)
        {

        }


    }


    public class RootModel
    {
        public int ID { get; set; }
        public Byte[] Root { get; set; }
        public string DescriptiveName { get; set; }
        public string Definition { get; set; }
        public int Length { get; set; }
        public string ContentType { get; set; }
        public string WpfPath { get; set; }
    }            
}

- xaml标记

<Window x:Class="TranshelperWpf.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:sys="clr-namespace:System;assembly=mscorlib"          
        xmlns:local="clr-namespace:TranshelperWpf"                         
        mc:Ignorable="d"
        Title="Trans-Help" Height="350" Width="525" Background="{DynamicResource WindowBackgroundBrush}">
    <Window.Resources>
        <LinearGradientBrush x:Key="WindowBackgroundBrush">
            <GradientStop Offset="0" Color="Silver"/>
            <GradientStop Offset="1" Color="Gray"/>
        </LinearGradientBrush>
        <RoutedUICommand x:Key="Roots" x:Name="_Roots"  />
        <RoutedUICommand x:Key="Usage" x:Name="_Usage"  />
    </Window.Resources>
    <Window.CommandBindings>
        <CommandBinding Command="{StaticResource Roots}" 
                            CanExecute="RootsCommandBinding_CanExecute" 
                            Executed="RootsCommandBinding_Executed" />
        <CommandBinding Command="{StaticResource Usage}" 
                            CanExecute="UsageCommandBinding_CanExecute" 
                            Executed="UsageCommandBinding_Executed" />
    </Window.CommandBindings>

    <DockPanel>
        <Menu DockPanel.Dock="Top">
            <MenuItem Header="_Admin">
                <MenuItem Header="_Roots" Command="{StaticResource Roots}" />
                <MenuItem Header="_Usage"/>
                <MenuItem Header="_Prefixes Suffixes" />
                <MenuItem Header="_Rules"/>
            </MenuItem>
        </Menu>
    </DockPanel>    
</Window>