WPF CommandParameter传多个能数到ViewModel?

WPF CommandParameter传多个能数到ViewModel?-急，在线等
我现在想传两个控件到一ViewModel，可是ViewModel的方法参数一直为null，取不到任何值。
有什么好的办法吗？
我的源码是这样的：

    <Window.Resources>
        <local:DataConverter x:Key="dataConverter"/>
    </Window.Resources>

<Button Header="添加用户" Icon="Images\Green.png" LargeIcon="Images\GreenLarge.png" x:Name="BtnAddUser" Command="{Binding AddUserCommand}">
                        <Button.CommandParameter>
                            <MultiBinding Converter="{ StaticResource ResourceKey=dataConverter}" Mode="TwoWay">
                                <MultiBinding.Bindings>
                                    <Binding ElementName="BtnAddUser"/>
                                    <Binding ElementName="dockManager "/>
                                </MultiBinding.Bindings>
                            </MultiBinding>
                        </Button.CommandParameter>
                        
</Button>

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace TLAgent.SecurityManager.WPF.MultiBindings
{
  public class DataConverter : IMultiValueConverter
  {
    #region IMultiValueConverter Members

    public static object ConverterObject;

    public object Convert(object[] values, Type targetType,
      object parameter, System.Globalization.CultureInfo culture)
    {
       ConverterObject = values;

        return values;
    }

    public object[] ConvertBack(object value, Type[] targetTypes,
      object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }

    #endregion
  }
}

------解决方案--------------------
在Convert 返回的时候新 new 一个object 返回就行了