Refresh filter when typing

[Daniel]

Hi,

I'm searching for a solution to filter the source immediately when the user types in the filter criteria. This is my declaration in my xaml:

<telerik:RadGridView Name="grvKanten" AutoGenerateColumns="False" IsReadOnly="True" CanUserReorderColumns="True" FilteringMode="FilterRow"
                     FilterOperatorsLoading="grvKanten_FilterOperatorsLoading" >
    <telerik:RadGridView.Columns>
        <telerik:GridViewDataColumn Name="colKantenname" DataMemberBinding="{Binding Kantenname}" Header="Kantenname" MinWidth="150"/>
        <telerik:GridViewDataColumn Name="colKantenbreitenname" DataMemberBinding="{Binding Kantenbreitenname}" Header="Kantenbreiten-Name" MinWidth="150"/>
        <telerik:GridViewDataColumn Name="colLagerplatz" DataMemberBinding="{Binding Lagerplatzname}" Header="Lagerplatz" MinWidth="150"/>
        <telerik:GridViewDataColumn Name="colLaenge" DataMemberBinding="{Binding Laenge}" Header="Länge" MinWidth="100"/>
        <telerik:GridViewDataColumn Name="colDekor" DataMemberBinding="{Binding Dekor}" Header="Dekor" MinWidth="100"/>
        <telerik:GridViewDataColumn Name="colBreie" DataMemberBinding="{Binding Breite}" Header="Kantenbreite" MinWidth="100"/>
    </telerik:RadGridView.Columns>
</telerik:RadGridView>

In my codebehind I delete some filter operators and set a default operator for each column when the FilterOperatorsLoading event is fired:

Private Sub grvKanten_FilterOperatorsLoading(sender As System.Object, e As Telerik.Windows.Controls.GridView.FilterOperatorsLoadingEventArgs)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.EndsWith)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsContainedIn)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsEmpty)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsEqualTo)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsGreaterThanOrEqualTo)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsLessThanOrEqualTo)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsNotEmpty)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsNotEqualTo)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsNotNull)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsNull)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.StartsWith)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsLessThan)
      e.AvailableOperators.Remove(Telerik.Windows.Data.FilterOperator.IsGreaterThan)
      e.DefaultOperator1 = Telerik.Windows.Data.FilterOperator.Contains
End Sub

So, if the user types in some filter criterias, I want the underlying source to be immediately refreshed every time the criteria changes without pressing the return button.

I tryed to set IsFilteringDeferred to false and true for some columns, but that doesn't seem to make a difference. The behavior is always the same: I have to press return to refresh the source.

Kind regards

[Dimitrina]

Hi,

I attached a demo project illustrating how you can filter when user types.

Regards,
Didie
Telerik

 

 

[Daniel]

Hi Didie,

thanks for this nice solution. It works great for me after converting to vb:

Private Sub grvKanten_FieldFilterEditorCreated(sender As Object, e As EditorCreatedEventArgs)
  Dim stringFilterEditor As StringFilterEditor = TryCast(e.Editor, StringFilterEditor)
  If Not stringFilterEditor Is Nothing Then
    AddHandler e.Editor.Loaded, Sub(s1, e1)
                                  Dim textBox__1 = e.Editor.ChildrenOfType(Of TextBox)().[Single]()
                                  AddHandler textBox__1.TextChanged, Sub(s2, e2)
                                                                       textBox__1.GetBindingExpression(TextBox.TextProperty).UpdateSource()
                                                                     End Sub
                                End Sub
  End If
End Sub

I just added some lines of code to make the example also work with types other than string:

Dim tb As TextBox = TryCast(e.Editor, TextBox)
If Not tb Is Nothing Then
  AddHandler tb.TextChanged, Sub(s2, e2)
                               tb.GetBindingExpression(TextBox.TextProperty).UpdateSource()
                             End Sub
End If

Kind regards

[Dimitrina]

Hi,

Thank you for sharing this additional code.

Regards,
Didie
Telerik

 

 

[Risa]

The above solution works for me for all text fields. However, it does not deal with numericfields. Is there a way to filter as the user is typing in numbers in a number field?

[Risa]

I believe I found the answer you my question. I've expanded the SetFilterAutoUpdate method to have an else statement, for non-text fields. If it's a numeric field, e.Editor will be a simple TextBox, and we can then subscribe to its TextChanged Event to update the filters immediately.

public static void SetFilterAutoUpdate(RadGridView grid, object sender, EditorCreatedEventArgs e)
    {
      if ((e.Editor is StringFilterEditor)) {
        e.Editor.Loaded += (RoutedEventHandler) ((s1, e1) => {
          TextBox textBox = e.Editor.ChildrenOfType<TextBox>().Single<TextBox>();
          textBox.TextChanged += (TextChangedEventHandler) ((s2, e2) => textBox.GetBindingExpression(TextBox.TextProperty).UpdateSource());
        });
       
      }
      else {
        TextBox textBox = e.Editor as TextBox;
        if (textBox != null) {
          textBox.TextChanged += (TextChangedEventHandler)((s2, e2) => textBox.GetBindingExpression(TextBox.TextProperty).UpdateSource());
        }
      }
    }