CODEWITHSUNDEEP
wpfdatagridwpftoolkitwpf-4.0
Gishu
Gishu

Reputation: 136593

How to select all the text when the edit textbox in a DataGridTemplateColumn receives focus?

I'm trying to get a DataGridTemplateColumn to behave identically to a TextColumn

Got the first one done ; however selecting all the text isn't working. As mentioned by a number of posts, tried hooking into the GotFocus event and selecting all the text in code-behind. This worked for a standalone textbox ; however for a Textbox which is the edit control for a TemplateColumn, this doesn't work.

Any ideas? Code Sample:

<Window.Resources>
            <Style x:Key="HighlightTextBoxStyle" TargetType="{x:Type TextBox}">
                <EventSetter Event="GotFocus" Handler="SelectAllText"/>
                <EventSetter Event="GotMouseCapture" Handler="SelectAllText"/>
                <Setter Property="Background" Value="AliceBlue"/>
            </Style>

            <DataTemplate x:Key="DefaultTitleTemplate">
                <TextBlock Text="{Binding Title}"/>
            </DataTemplate>
            <DataTemplate x:Key="EditTitleTemplate">
                    <TextBox x:Name="Fox"
                         FocusManager.FocusedElement="{Binding RelativeSource={RelativeSource Self}}"  
                         Text="{Binding Path=Title, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                         Style="{StaticResource HighlightTextBoxStyle}">
                    </TextBox>
            </DataTemplate>
        </Window.Resources>
        <DockPanel>
            <TextBox DockPanel.Dock="Top" x:Name="Test" Text="{Binding Path=(FocusManager.FocusedElement).Name, ElementName=MyWindow}" 
                     Style="{StaticResource HighlightTextBoxStyle}"/>
            <toolkit:DataGrid ItemsSource="{Binding Items}" AutoGenerateColumns="False">
                <toolkit:DataGrid.Columns>
                    <toolkit:DataGridTemplateColumn Header="Templated Title" 
                        CellTemplate="{StaticResource DefaultTitleTemplate}"
                        CellEditingTemplate="{StaticResource EditTitleTemplate}" />

                    <toolkit:DataGridTextColumn Header="Title" Binding="{Binding Path=Title}" />
                </toolkit:DataGrid.Columns>
            </toolkit:DataGrid>
        </DockPanel>

Upvotes: 10

Views: 8133

Answers (3)

SiRaDuDe
SiRaDuDe

Reputation: 41

Kinda VERY late...just putting this out here in case someone can use this

I had a similar need to DeSelect (or Select All) text in a DataGridTextColumn on editing

Just added the method to the PreparingCellForEdit event of the DataGrid

        DataGrid.PreparingCellForEdit += DataGrid_PreparingCellForEdit;

Then assigned the (e.EditingElement as TextBox) and then set my options

 private void DataGrid_PreparingCellForEdit(object sender, DataGridPreparingCellForEditEventArgs e)
    {
        var txtBox = e.EditingElement as TextBox;
        txtBox.Select(txtBox.Text.Length, 0); //to DeSelect all and place cursor at end
        txtBox.SelectAll(); // to selectall
    }

Upvotes: 1

Ben
Ben

Reputation: 63

I know this is way late but I took a different approach and creatively extended the TextBox class. I don't really like using the boolean to check if the text is already defined but the problem is that the selection events all fire before the text is set from the binding so SelectAll() doesn't have anything to select! This class is probably only useful as a editing template in something like a DataGridTemplateColumn. Every solution I found for this issue is pretty much a hack so I don't feel too bad about this one ... :)

class AutoSelectTextBox : TextBox
{
    private bool _autoSelectAll= true;

    protected override void OnInitialized(EventArgs e)
    {
        // This will cause the cursor to enter the text box ready to
        // type even when there is no content.
        Focus();
        base.OnInitialized(e);
    }

    protected override OnKeyDown(System.Windows.Input.KeyEventArgs e)
    {
        // This is here to handle the case of an empty text box.  If
        // omitted then the first character would be auto selected when
        // the user starts typing.
        _autoSelectAll = false;
        base.OnKeyDown(e);
    }


    protected override void OnTextChanged(TextChangedEventArgs e)
    {
        if (_autoSelectAll)
        {
            SelectAll();
            Focus();
            _autoSelectAll= false;
        }
        base.OnTextChanged(e);
    }
}

Upvotes: 0

Gishu
Gishu

Reputation: 136593

Missed updating the post with an answer...

The problem seems to be that for a custom data grid column (aka a DataGridTemplateColumn) the grid has no way of knowing the exact type of the editing control (which is specified via a DataTemplate and could be anything). For a DataGridTextColumn, the editing control type is known and hence the grid can find it and invoke a SelectAll() in it.

So to achieve the end-goal for a TemplateColumn, you need to provide an assist. I forgotten how I solved it the first time around.. but here is something that I searched-tweaked out today. Create a custom derivation of a TemplateColumn with an override of the PrepareCellForEdit method as shown below (Swap Textbox with your exact editing control).

public class MyCustomDataColumn : DataGridTemplateColumn
    {
        protected override object PrepareCellForEdit(FrameworkElement editingElement, RoutedEventArgs editingEventArgs)
        {
            var contentPresenter = editingElement as ContentPresenter;

            var editingControl = FindVisualChild<TextBox>(contentPresenter);
            if (editingControl == null)
                return null;

            editingControl.SelectAll();
            return null;
        }

        private static childItem FindVisualChild<childItem>(DependencyObject obj) 
    }

Here's an implementation for FindVisualChild.

XAML:

   <WPFTestBed:MyCustomDataColumn Header="CustomColumn"
                    CellTemplate="{StaticResource DefaultTitleTemplate}"
                    CellEditingTemplate="{StaticResource EditTitleTemplate}"/>
</DataGrid.Columns>

Lot of code for an annoying inconsistency.

Upvotes: 8

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