Multiline editable combo in WPF
Today I am going to share a interesting learning experience that I had about editable combo box. In one of my project we have a requirement that all editable text need to support multi-line support. very easy stuff. Just set IsEditable property of combo box to "true".
1: <ComboBox x:Name="ddlCombo"
2: MaxDropDownHeight="200"
3: FontWeight="Normal"
4: Text="{my:CellEditorBinding}"
5: BorderThickness="0"
6: Padding="0" Margin="0"
7: IsEditable="True"
8: Foreground="Black" />
Now, the problem is, in couple of our grid cell we had combo box with editable feature. User can write their own choice or they can pick a value from the drop down list. since the text box of combo is a text editing area. clients wanted warp text with new line in the edit area of the combo box. After few minutes of "R & D" we discovered the way to override the control template and modified the textbox of combo box in such a way so that it can take multi-line and warp text content in combo box.
To give a textbox warped text feature i just added the following code, and it will do the job.
1: <TextBox x:Name="PART_EditableTextBox"
2: Style="{x:Null}"
3: Template="{StaticResource ComboBoxTextBox}"
4: HorizontalAlignment="Left"
5: VerticalAlignment="Center"
6: Margin="3,3,23,3"
7: Focusable="True"
8: Background="Transparent"
9: Visibility="Hidden"
10: TextWrapping="Wrap"
11: AcceptsReturn="True"
12: IsReadOnly="{TemplateBinding IsReadOnly}"/>
Best of luck and happy programming.