When you want to display separate filtering options for built-in GridCheckBoxColumn a suitable solution might be to remove the default filter text box and image and put a dropdown list in the column header (with ClearFilter/Show all checked/Show all unchecked options). Thus you can filter the grid records according to the chosen condition and still keep the default filtering menu for the rest of the grid columns.
To replace the default textbox filter for GridCheckBoxColumn you can wire the ItemCreated event of the grid and modify the Controls collection of the corresponding header cell. You also need to wire the SelectedIndexChanged event of the dropdown list (which will be in the place of the textbox) in order to modify the grid FilterExpression in par with the SelectedValue of he combobox.
Finally, to persist the filter criteria for the checkbox column when you trigger filter action from other column, hook the NeedDataSource event and add the necessary pattern to the FilterExpression.
Below are some code snippets showing the approach:
| ASPX/ASCX |
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<rad:RadGrid ID="RadGrid1" AllowSorting="True" AllowPaging="true" EnableAJAX="true" ShowStatusBar="true"
Skin= "Windows" runat="server" GridLines="None" Width="300px" AllowFilteringByColumn="true">
<PagerStyle Mode="NextPrevAndNumeric" />
<MasterTableView AutoGenerateColumns="false">
<Columns>
<rad:GridCheckBoxColumn UniqueName="GridCheckBoxColumn" DataField="Bool" HeaderText="Check/UnCheck" />
<rad:GridBoundColumn UniqueName="ContactName" HeaderText="Contact name" DataField="ContactName" />
</Columns>
</MasterTableView>
<PagerStyle Mode="NumericPages" />
</rad:RadGrid> |
| C# |
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string connectionString = ("Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + System.Web.HttpContext.Current.Server.MapPath( "~/Grid/Data/Access/Nwind.mdb"));
public DataTable GetDataTable(string query)
{
OleDbConnection connection1 = new OleDbConnection(connectionString);
OleDbDataAdapter adapter1 = new OleDbDataAdapter();
adapter1.SelectCommand = new OleDbCommand(query, connection1);
DataTable table1 = new DataTable();
connection1. Open();
try
{
adapter1.Fill(table1);
}
finally
{
connection1. Close();
}
return table1;
}
protected void RadGrid1_ItemCreated(object sender, Telerik.WebControls.GridItemEventArgs e)
{
if (e.Item is GridFilteringItem)
{
GridFilteringItem filteringItem = (e.Item as GridFilteringItem);
filteringItem[ "GridCheckBoxColumn"].Controls.Clear();
DropDownList ddList = new DropDownList();
ddList.AutoPostBack = true;
ddList.SelectedIndexChanged += new System.EventHandler(this.ddList_SelectedIndexChanged);
ddList.Items.Add( new ListItem("Clear filter", "Empty"));
ddList.Items.Add( new ListItem("Show all checked", "True"));
ddList.Items.Add( new ListItem("Show all unchecked", "False"));
if (Session["ddlSelValue"] != null)
{
ddList.Items.FindByValue(( string)Session("ddlSelValue")).Selected = true;
}
filteringItem[ "GridCheckBoxColumn"].Controls.Add(ddList);
}
}
protected void ddList_SelectedIndexChanged(object sender, System.EventArgs e)
{
DropDownList ddList = (DropDownList)sender;
Session["ddlSelValue"] = ddList.SelectedValue;
switch (ddList.SelectedValue)
{
case "True":
RadGrid1.MasterTableView.FilterExpression = "([Bool] = True) ";
foreach (GridColumn column in RadGrid1.MasterTableView.Columns)
{
column.CurrentFilterFunction = GridKnownFunction.NoFilter;
column.CurrentFilterValue = String.Empty;
}
RadGrid1.MasterTableView.Rebind();
break;
case "False":
RadGrid1.MasterTableView.FilterExpression = "([Bool] = False) ";
foreach (GridColumn column in RadGrid1.MasterTableView.Columns)
{
column.CurrentFilterFunction = GridKnownFunction.NoFilter;
column.CurrentFilterValue = String.Empty;
}
RadGrid1.MasterTableView.Rebind();
break;
case "Empty":
RadGrid1.MasterTableView.FilterExpression = String.Empty;
foreach (GridColumn column in RadGrid1.MasterTableView.Columns)
{
column.CurrentFilterFunction = GridKnownFunction.NoFilter;
column.CurrentFilterValue = String.Empty;
}
RadGrid1.MasterTableView.Rebind();
break;
}
}
protected void RadGrid1_NeedDataSource(object source, Telerik.WebControls.GridNeedDataSourceEventArgs e)
{
RadGrid1.DataSource = GetDataTable("Select ContactName, Bool FROM Customers");
if (Session["ddlSelValue"] != null)
{
RadGrid1.MasterTableView.FilterExpression = RadGrid1.MasterTableView.FilterExpression + "AND ([Bool] = "
+ (string)Session("ddlSelValue") + ")";
}
} |
| VB.NET |
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Public Shared connectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & System.Web.HttpContext.Current.Server.MapPath( "~/Grid/Data/Access/Nwind.mdb")
Public Function GetDataTable(ByVal query As String) As DataTable
Dim connection1 As New OleDbConnection(connectionString)
Dim adapter1 As New OleDbDataAdapter
adapter1.SelectCommand = New OleDbCommand(query, connection1)
Dim table1 As New DataTable
connection1. Open()
Try
adapter1.Fill(table1)
Finally
connection1. Close()
End Try
Return table1
End Function
Protected Sub RadGrid1_ItemCreated(ByVal sender As Object, ByVal e As Telerik.WebControls.GridItemEventArgs) Handles RadGrid1.ItemCreated
If (TypeOf e.Item Is GridFilteringItem) Then
Dim filteringItem As GridFilteringItem = CType(e.Item, GridFilteringItem)
filteringItem( "GridCheckBoxColumn").Controls.Clear()
Dim ddList As DropDownList = New DropDownList()
ddList.AutoPostBack = True
AddHandler ddList.SelectedIndexChanged, AddressOf ddList_SelectedIndexChanged
ddList.Items.Add( New ListItem("Clear filter", "Empty"))
ddList.Items.Add( New ListItem("Show all checked", "True"))
ddList.Items.Add( New ListItem("Show all unchecked", "False"))
If (Not Session("ddlSelValue") Is Nothing) Then
ddList.Items.FindByValue(CType(Session( "ddlSelValue"), String)).Selected = True
End If
filteringItem( "GridCheckBoxColumn").Controls.Add(ddList)
End If
End Sub
Protected Sub ddList_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Dim ddList As DropDownList = CType(sender, DropDownList)
Session( "ddlSelValue") = ddList.SelectedValue
Select Case ddList.SelectedValue
Case "True"
RadGrid1.MasterTableView.FilterExpression = "([Bool] = True) "
For Each column As GridColumn In RadGrid1.MasterTableView.Columns
column.CurrentFilterFunction = GridKnownFunction.NoFilter
column.CurrentFilterValue = String.Empty
Next
RadGrid1.MasterTableView.Rebind()
Case "False"
RadGrid1.MasterTableView.FilterExpression = "([Bool] = False) "
For Each column As GridColumn In RadGrid1.MasterTableView.Columns
column.CurrentFilterFunction = GridKnownFunction.NoFilter
column.CurrentFilterValue = String.Empty
Next
RadGrid1.MasterTableView.Rebind()
Case "Empty"
RadGrid1.MasterTableView.FilterExpression = String.Empty
For Each column As GridColumn In RadGrid1.MasterTableView.Columns
column.CurrentFilterFunction = GridKnownFunction.NoFilter
column.CurrentFilterValue = String.Empty
Next
RadGrid1.MasterTableView.Rebind()
End Select
End Sub
Protected Sub RadGrid1_NeedDataSource(ByVal source As Object, ByVal e As Telerik.WebControls.GridNeedDataSourceEventArgs) Handles RadGrid1.NeedDataSource
RadGrid1.DataSource = GetDataTable("Select ContactName, Bool FROM Customers")
If (Not Session("ddlSelValue") Is Nothing) Then
RadGrid1.MasterTableView.FilterExpression = RadGrid1.MasterTableView.FilterExpression & "AND ([Bool] = " & CType(Session("ddlSelValue"), String) & ")"
End If
End Sub |