RadGrid for ASP.NET
Table of Contents
Persisting the selected rows on sorting/paging/filtering/grouping Send comments on this topic.
See Also
Selecting grid items > How-to > Persisting the selected rows on sorting/paging/filtering/grouping

Glossary Item Box

This behavior is not supported out-of-the-box by our control. However, it is achievable through a custom implementation as follows:

  1. Store the primary key values for the selected rows in a Session object on Select command execution and remove it on Deselect;
  2. On sort/page/filter/group command, traverse the grid rows and set those with primary keys present in the Session object with Selected = True;
  3. To safely apply the selection for the marked grid rows, hook the PreRender event of the grid and check whether the Session object holding the primary fields for the selected records is not empty.
Note: The example will work when you select/deselect rows using the Select/Deselect button columns in the grid.

ASPX/ASCX Copy Code
<rad:RadGrid ID="RadGrid1" DataSourceID="AccessDataSource1" runat="server" Width="97%"
 PageSize="15" AllowSorting="True" AllowMultiRowSelection="True" Skin="Outlook"
 AllowPaging="True" ShowGroupPanel="True" AutoGenerateColumns="False" AllowFilteringByColumn="true" EnableAJAX="true" ShowStatusBar="true"
 OnItemCommand="RadGrid1_ItemCommand" OnPreRender="RadGrid1_PreRender">
         <PagerStyle Mode="NextPrevAndNumeric" />
               <MasterTableView Width="100%" DataKeyNames="CustomerID" AllowFilteringByColumn="true">
                   <Columns>
                       <rad:GridBoundColumn SortExpression="Country" HeaderText="Country" HeaderButtonType="TextButton"
                           DataField="Country">
                       </rad:GridBoundColumn>
                       <rad:GridBoundColumn SortExpression="City" HeaderText="City" HeaderButtonType="TextButton"
                           DataField="City">
                       </rad:GridBoundColumn>
                       <rad:GridBoundColumn SortExpression="CompanyName" HeaderText="Company Name" HeaderButtonType="TextButton"
                           DataField="CompanyName">
                       </rad:GridBoundColumn>
                       <rad:GridBoundColumn SortExpression="ContactName" HeaderText="Contact Name" HeaderButtonType="TextButton"
                           DataField="ContactName">
                       </rad:GridBoundColumn>
                       <rad:GridBoundColumn SortExpression="ContactTitle" HeaderText="Contact Title" HeaderButtonType="TextButton"
                           DataField="ContactTitle">
                       </rad:GridBoundColumn>
                       <rad:GridButtonColumn UniqueName="SelectColumn" CommandName="Select" Text="Select" />
                       <rad:GridButtonColumn UniqueName="DeselectColumn" CommandName="Deselect" Text="Deselect" />
                   </Columns>
               </MasterTableView>
               <ClientSettings AllowDragToGroup="True" />
</rad:RadGrid>
<br />
<asp:AccessDataSource ID="AccessDataSource1" DataFile="~/Grid/Data/Access/Nwind.mdb"
 SelectCommand="SELECT * FROM Customers" runat="server"></asp:AccessDataSource>

And in the code-behind:

VB.NET Copy Code
Dim selectedItems As ArrayList

Protected Sub RadGrid1_ItemCommand(ByVal source As Object, ByVal e As GridCommandEventArgs) Handles RadGrid1.ItemCommand
 If Session("selectedItems") Is Nothing Then
   selectedItems = New ArrayList
 Else
   selectedItems = CType(Session("selectedItems"), ArrayList)
 End If

 If e.CommandName = RadGrid.SelectCommandName AndAlso TypeOf e.Item Is GridDataItem Then
   Dim dataItem As GridDataItem = CType(e.Item, GridDataItem)
   Dim customerID As String = dataItem.OwnerTableView.DataKeyValues(dataItem.ItemIndex)("CustomerID").ToString
   selectedItems.Add(customerID)
   Session("selectedItems") = selectedItems
 End If

 If e.CommandName = RadGrid.DeselectCommandName AndAlso TypeOf e.Item Is GridDataItem Then
   Dim dataItem As GridDataItem = CType(e.Item, GridDataItem)
   Dim customerID As String = dataItem.OwnerTableView.DataKeyValues(dataItem.ItemIndex)("CustomerID").ToString
   selectedItems.Remove(customerID)
   Session("selectedItems") = selectedItems
 End If
End Sub

Protected Sub RadGrid1_PreRender(ByVal sender As Object, ByVal e As EventArgs) Handles RadGrid1.PreRender
 If Not (Session("selectedItems") Is Nothing) Then
   selectedItems = CType(Session("selectedItems"), ArrayList)

   Dim stackIndex As Int16

   For stackIndex = 0 To selectedItems.Count - 1
     Dim curItem As String = selectedItems(stackIndex).ToString

     For Each item As GridItem In RadGrid1.MasterTableView.Items
       If TypeOf item Is GridDataItem Then
         Dim dataItem As GridDataItem = CType(item, GridDataItem)
         If curItem.Equals(dataItem.OwnerTableView.DataKeyValues(dataItem.ItemIndex)("CustomerID").ToString()) Then
           dataItem.Selected = True
         End If
       End If
     Next
   Next
 End If
End Sub

 

C# Copy Code
ArrayList selectedItems;

protected void RadGrid1_ItemCommand(object source, GridCommandEventArgs e)
{
       if (Session["selectedItems"] == null)
       {
           selectedItems = new ArrayList();
       }
       else
       {
           selectedItems = (ArrayList)Session["selectedItems"];
       }
       if (e.CommandName == RadGrid.SelectCommandName && e.Item is GridDataItem)
       {
           GridDataItem dataItem = (GridDataItem)e.Item;
           string customerID = dataItem.OwnerTableView.DataKeyValues[dataItem.ItemIndex]["CustomerID"].ToString();
           selectedItems.Add(customerID);
           Session["selectedItems"] = selectedItems;
       }
       if (e.CommandName == RadGrid.DeselectCommandName && e.Item is GridDataItem)
       {
           GridDataItem dataItem = (GridDataItem)e.Item;
           string customerID = dataItem.OwnerTableView.DataKeyValues[dataItem.ItemIndex]["CustomerID"].ToString();
           selectedItems.Remove(customerID);
           Session["selectedItems"] = selectedItems;
       }
}
protected void RadGrid1_PreRender(object sender, EventArgs e)
{
       if (Session["selectedItems"] != null)
       {
           selectedItems = (ArrayList)Session["selectedItems"];
           Int16 stackIndex;
           for (stackIndex = 0; stackIndex <= selectedItems.Count - 1; stackIndex++)
           {
               string curItem = selectedItems[stackIndex].ToString();
               foreach (GridItem item in RadGrid1.MasterTableView.Items)
               {
                   if (item is GridDataItem)
                   {
                       GridDataItem dataItem = (GridDataItem)item;
                       if (curItem.Equals(dataItem.OwnerTableView.DataKeyValues[dataItem.ItemIndex]["CustomerID"].ToString()))
                       {
                           dataItem.Selected = true;
                           break;
                       }
                   }
               }
           }
       }
}

 

See Also