DevExpress WPF Unbound Column with Expression Editor

我正试图将一个未绑定的列添加到我的GridControl中，同时启用它上的表达式编辑器，这样当我打开它并编写有效的表达式时，列值应该会相应地更改，但它不起作用。我有一个GridControl，它有3列：第1列、第2列和第3列。第3列是未绑定的列。表达式编辑器会正确打开，并允许我编写表达式，但当我单击"确定"时，值永远不会更改，无论我编写什么。

我使用的是DevExpress 13.1，不可能升级。这是我的代码：

XAML:

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
    x:Class="ExpressionEditor.MainWindow"
    Title="Expression Editor" Height="350" Width="525">
    <dxg:GridControl x:Name="myGridControl">
        <dxg:GridControl.Columns>
            <dxg:GridColumn FieldName="Column1" />
            <dxg:GridColumn FieldName="Column2" />
            <dxg:GridColumn FieldName="Column3" 
                            UnboundType="Decimal" 
                            ReadOnly="True" />
        </dxg:GridControl.Columns>
        <dxg:GridControl.View>
            <dxg:TableView x:Name="myTableView" 
                           NavigationStyle="Cell" />
        </dxg:GridControl.View>
    </dxg:GridControl>
</Window>

代码背后：

using System.Collections.ObjectModel;
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow
{
    #region Properties
    /// <summary>
    /// Gets or sets the data table2.
    /// </summary>
    /// <value>
    /// The data table2.
    /// </value>
    public ObservableCollection<CustomRow> DataTable { get; set; }
    #endregion
    #region Constructors
    /// <summary>
    /// Initializes a new instance of the <see cref="MainWindow"/> class.
    /// </summary>
    public MainWindow()
    {
        this.InitializeComponent();
        this.DataTable = new ObservableCollection<CustomRow>();
        this.myGridControl.ItemsSource = this.DataTable;
        this.Init();
    }
    #endregion
    #region Methods
    private void Init()
    {
        // Add Data
        this.DataTable.Add(new CustomRow { Column1 = 100, Column2 = 200 });
        this.DataTable.Add(new CustomRow { Column1 = 300, Column2 = 400 });
        // Add Unbound Column
        var column = this.myGridControl.Columns["Column3"];
        column.AllowUnboundExpressionEditor = true;
    }
    #endregion
}

CustomRow类：

/// <summary>
/// Custom Row
/// </summary>
public class CustomRow
{
    #region Properties
    /// <summary>
    /// Gets or sets the column1.
    /// </summary>
    /// <value>
    /// The column1.
    /// </value>
    public double Column1 { get; set; }
    /// <summary>
    /// Gets or sets the column2.
    /// </summary>
    /// <value>
    /// The column2.
    /// </value>
    public double Column2 { get; set; }
    /// <summary>
    /// Gets or sets the column3.
    /// </summary>
    /// <value>
    /// The column3.
    /// </value>
    public double Column3 { get; set; }
    #endregion
}