wpf GridControl selectAll UnSelect

 <Window x:Class="WpfApplication1.GridControlView"
         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"
         xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
         xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
         Title="GridControlView" >
     <Grid>
         <StackPanel>
             <Button Click="BtnInvert_Click">Invert selection</Button>
             <Button Click="BtnGetSelected_Click">Get selection</Button>
             <dxg:GridControl x:Name="grid" CustomUnboundColumnData="grid_CustomUnboundColumnData" Height="" ItemsSource="{Binding List}">
                 <dxg:GridControl.Columns>
                     <dxg:GridColumn FieldName="Id" />
                     <dxg:GridColumn FieldName="Number" />
                     <dxg:GridColumn FieldName="Selected" UnboundType="Boolean" AllowSorting="False">
                         <dxg:GridColumn.CellTemplate>
                             <DataTemplate>
                                 <dxe:CheckEdit IsChecked="{Binding Data.Selected}" HorizontalAlignment="Center" VerticalAlignment="Center" />
                             </DataTemplate>
                         </dxg:GridColumn.CellTemplate>
                     </dxg:GridColumn>
                 </dxg:GridControl.Columns>
                 <dxg:GridControl.View>
                     <dxg:TableView x:Name="view" AutoWidth="True" />
                 </dxg:GridControl.View>
             </dxg:GridControl>
         </StackPanel>
     </Grid>
 </Window>

GridControlView.xaml

 /// <summary>
     /// GridControlView.xaml 的交互逻辑
     /// </summary>
     public partial class GridControlView : Window
     {
         public GridControlView()
         {
             InitializeComponent();
             //Dxsl.LoginManage.ViewModels.LookupControlViewModel viewModel = new Dxsl.LoginManage.ViewModels.LookupControlViewModel();

             //this.DataContext = viewModel;
             DataContext = data;
         }

         TestData data = new TestData();
         SelectionHelper<Guid> selectionHelper = new SelectionHelper<Guid>();

         /// <summary>
         /// Grid触发事件
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void grid_CustomUnboundColumnData(object sender, GridColumnDataEventArgs e)
         {
             if (e.Column.FieldName != "Selected") return;
             Guid key = (Guid)e.GetListSourceFieldValue("Id");
             if (e.IsGetData)
                 e.Value = selectionHelper.GetIsSelected(key);
             if (e.IsSetData)
                 selectionHelper.SetIsSelected(key, (bool)e.Value);
         }
         /// <summary>
         /// 全选或者反选
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void BtnInvert_Click(object sender, RoutedEventArgs e)
         {
             for (int i = ; i < data.List.Count; i++)
             {
                 int rowHandle = this.grid.GetRowHandleByListIndex(i);
                 bool newIsSelected = !selectionHelper.GetIsSelected(data.List[i].Id);
                 grid.SetCellValue(rowHandle, "Selected", newIsSelected);
             }
         }
         /// <summary>
         /// 获取选中项
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void BtnGetSelected_Click(object sender, RoutedEventArgs e)
         {
             string caption = string.Format("Selected rows (Total: {0})", selectionHelper.GetSelectionCount());
             MessageBox.Show(selectionHelper.GetSelectedKeysAsString(), caption);
         }
     }

GridControlView

  /// <summary>
     /// 选择帮助类
     /// </summary>
     /// <typeparam name="KeyType">类型</typeparam>
     public class SelectionHelper<KeyType>
     {
         /// <summary>
         /// 选中集合字典
         /// </summary>
         Dictionary<KeyType, bool> selectedValues = new Dictionary<KeyType, bool>();
         /// <summary>
         /// 获取key是否被选中
         /// </summary>
         /// <param name="key">key 值</param>
         /// <returns></returns>
         public bool GetIsSelected(KeyType key)
         {
             //声明是否选择变量,默认为false
             bool isSelected;
             if (selectedValues.TryGetValue(key, out isSelected))
                 return isSelected;
             return false;
         }
         /// <summary>
         /// 设置选中项的值
         /// </summary>
         /// <param name="key">key 值</param>
         /// <param name="value">true or false</param>
         public void SetIsSelected(KeyType key, bool value)
         {
             if (value)
                 selectedValues[key] = value;
             else
                 selectedValues.Remove(key);
         }
         /// <summary>
         /// 获取集合字典中的选中项
         /// </summary>
         /// <returns></returns>
         public List<KeyType> GetSelectedKeys()
         {
             List<KeyType> list = new List<KeyType>();
             //遍历集合
             foreach (KeyType key in selectedValues.Keys)
                 list.Add(key);
             return list;
         }
         /// <summary>
         /// 获取集合中项 加入StringBuilder 仅测试用
         /// </summary>
         /// <returns></returns>
         public string GetSelectedKeysAsString()
         {
             List<KeyType> list = GetSelectedKeys();
             StringBuilder str = new StringBuilder();
             for (int i = ; i < list.Count; i++)
                 str.AppendLine(list[i].ToString());
             return str.ToString();
         }
         /// <summary>
         /// 获取选择数量
         /// </summary>
         /// <returns></returns>
         public int GetSelectionCount()
         {
             return selectedValues.Count;
         }
     }

SelectionHelper

     public class TestData
     {
         public List<TestDataItem> List { get; private set; }
         public TestData()
         {
             List<TestDataItem> list = new List<TestDataItem>();
             for (int i = ; i < ; i++)
             {
                 list.Add(new TestDataItem() { Id = Guid.NewGuid(), Number = i });
             }
             List = list;
         }
     }

TestData

     public class TestDataItem
     {
         public Guid Id { get; set; }
         public int Number { get; set; }
     }

TestDataItem