数据绑定菜单中的菜单项在WPF中显示奇怪

Question

我的XAML中有以下代码：

            <Menu x:Name="MainMenu" VerticalAlignment="Top" DockPanel.Dock="Top" Padding="0,3">
            <Menu.ItemTemplate>
                <DataTemplate>
                    <MenuItem Header="{Binding Text}" Icon="{Binding Icon}" ToolTip="{Binding Tooltip}" Command="{Binding Path=ClickCommand}" HorizontalAlignment="Left">
                    </MenuItem>
                </DataTemplate>
            </Menu.ItemTemplate>
        </Menu>

然后我绑定ItemsSource属性并用插件中的菜单项填充它。

不是我认为它是相关的，这里有一些代码：

MainMenu.ItemsSource = Global.MainMenu; //You can assume the Global class is exactly what it looks like, a shared class holding many of the programs settings and stores.

ApplicationMenuItem mappingMenu = new ApplicationMenuItem();
mappingMenu.Text = "Edit Mapping";
mappingMenu.Clicked += (se, ev) => { MainFrame.Navigate(new Pages.DeviceMapping()); };
Global.MainMenu.Add(mappingMenu);

-

    public class ApplicationMenuItem
{
    public ImageSource Icon { get; set; }
    public string Text { get; set; }
    public string Tooltip { get; set; }
    public bool Enabled { get; set; }
    public ICollection<ApplicationMenuItem> Items { get; set; }
    public EventHandler Clicked {get;set;}
    public void Click(object sender, EventArgs e)
    {
        if (Clicked!=null)
            Clicked(this, e);
    }
    private ICommand _ClickCommand;
    public ICommand ClickCommand
    {
        get
        {
            if (_ClickCommand == null)
            {
                _ClickCommand = new RelayCommand(param => this.Click(this, EventArgs.Empty));
            }
            return _ClickCommand;
        }
    }
    public ApplicationMenuItem(string Text)
    {
        this.Text = Text;
        Items = new List<ApplicationMenuItem>();
    }
    public ApplicationMenuItem()
    {
        Items = new List<ApplicationMenuItem>();
    }

}
public class RelayCommand : ICommand
{
    #region Fields

    readonly Action<object> _execute;
    readonly Predicate<object> _canExecute;

    #endregion // Fields

    #region Constructors

    /// <summary>
    /// Creates a new command that can always execute.
    /// </summary>
    /// <param name="execute">The execution logic.</param>
    public RelayCommand(Action<object> execute)
        : this(execute, null)
    {
    }

    /// <summary>
    /// Creates a new command.
    /// </summary>
    /// <param name="execute">The execution logic.</param>
    /// <param name="canExecute">The execution status logic.</param>
    public RelayCommand(Action<object> execute, Predicate<object> canExecute)
    {
        if (execute == null)
            throw new ArgumentNullException("execute");

        _execute = execute;
        _canExecute = canExecute;
    }

    #endregion // Constructors

    #region ICommand Members

    [DebuggerStepThrough]
    public bool CanExecute(object parameters)
    {
        return _canExecute == null ? true : _canExecute(parameters);
    }

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public void Execute(object parameters)
    {
        _execute(parameters);
    }

    #endregion // ICommand Members
}

问题是项目没有以我期望的方式显示，它们似乎比MenuItem控件内的正常Menu宽得多，并且似乎被包裹在另一个控件中导致双边界。

我哪里出错了，我没有正确使用菜单的绑定吗？