ContextMenu和TextBox的WPF数据绑定

Question

我的小WPF托盘图标有问题，该图标已分配上下文菜单。如果我右键单击托盘图标，则会打开上下文菜单，您会看到一个包含整数值的文本框。现在点击＆＃34;创建实例＆＃34;字段整数应该加1。新值应显示在文本框中。启动时，文本框中会显示正确的初始值，但运行期间的更改不会反映到UI。我认为存在数据绑定问题...捕获了click事件，甚至值增加但文本框无法识别新值......

我没有主窗口，应用程序应该只是一个托盘图标上下文菜单。

App.xaml.cs

public partial class App : Application
{
    // This objects are global
    private TaskbarIcon notifyIcon;
    private INotificationBarMessage message = null;

    protected override void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);

        //create the notifyicon (a resource declared in NotifyIconResources.xaml)
        notifyIcon = (TaskbarIcon) FindResource("Key_NotifyIcon");
        notifyIcon.DataContext = this;

        message = new NotificationBarMessage(notifyIcon);
        message.Show(TextType.Startup);
    }
}

ResourceContextMenu.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:tb="http://www.hardcodet.net/taskbar"
                    xmlns:local="clr-namespace:UserInterface.ViewModel"
                    x:Class="UserInterface.ViewModel.EventHandlerUI">

<ContextMenu x:Shared="false" x:Key="My_ContextMenu">
    <ContextMenu.DataContext>
        <local:ContextMenuModel /> <!-- reference to ContextMenuModel.cs -->
    </ContextMenu.DataContext>

    <!-- DataContext="{Binding PlacementTarget.DataContext,
         RelativeSource={RelativeSource Self}} -->
    <ContextMenu.Resources>
        <local:ConverterBoolToVisibility x:Key="BoolToHiddenConverter"
                                         TrueValue="Visible" 
                                         FalseValue="Hidden" />
        <local:ConverterIntToString x:Key="IntToStringConverter" />
    </ContextMenu.Resources>

    <TextBlock Text="Status"/>

    <Separator/>

    <MenuItem Header="Create Instance"
              MouseEnter="CreateInstance_OverEnter"
              MouseLeave="CreateInstance_OverExit"
              Click="CreateInstance_Click"
              StaysOpenOnClick="True" />
        <!-- Command="{Binding ShowWindowCommand}" -->
    <MenuItem Header="Open Window"
              StaysOpenOnClick="True"
              Command="{Binding Commands.ShowWindowCommand}" />   
    <MenuItem Header="IP-Address"
              Name="MenuItem_IPAddress"
              Visibility="{Binding EventData.IsEnabled, Mode=TwoWay,
                  Converter={StaticResource BoolToHiddenConverter}}"
              StaysOpenOnClick="True"/>
    <TextBox Width="100"
             Text="{Binding Path=EventData.Counter,
                 UpdateSourceTrigger=PropertyChanged, Mode=TwoWay,
                 Converter={StaticResource IntToStringConverter}}"/>

    <Separator/>

    <MenuItem Header="Exit"
              Command="{Binding Path=Commands.ExitApplicationCommand}" />
</ContextMenu>

<!-- Tray Icon -->
<!-- the application's NotifyIcon - started from App.xaml.cs.
     Declares its own view model. -->
<tb:TaskbarIcon x:Key="Key_NotifyIcon"
                x:Name="My_NotifyIcon"
                IconSource="/View/gfx/_UserInterface.ico"
                ToolTipText="tip"
                ContextMenu="{StaticResource My_ContextMenu}"/>

的App.xaml

<Application x:Class="UserInterface.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             ShutdownMode="OnExplicitShutdown">
<Application.Resources>
    <!-- Note that this application does not have a StartupUri declared,
         so no Window is automatically loaded.
         Also, the ShutdownMode was set to explicit,
         so we have to close the application programmatically. -->

    <!-- merge NotifyIcon and related stuff into the application -->
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="ResourceContextMenu.xaml" />
        </ResourceDictionary.MergedDictionaries>
    </ResourceDictionary>
</Application.Resources>

以下是我触发属性更改事件的代码：

private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
    if (PropertyChanged != null)
    {
        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}

private int _counter = 34;

public int Counter
{
    get
    {
        return this._counter;
    }
    set
    {
        if (value != this._counter)
        {
            this._counter = value;
            NotifyPropertyChanged();
        }
    }
}

任何帮助都将不胜感激。