WPF DataGrid, Read-Only Row

/ By / In WPF, XAML / 4 Comments

A common requirement for a DataGrid is to have entire rows that are read-only.  You may have a list of records in your DataGrid and some need to be locked for various reasons.  Unfortunately, in the XAML definition of a DataGrid, there isn’t a way to mark a row as being Read-Only.  To accomplish this without tying my view to my model or rewriting the DataGrid, I’m utilizing the BeginningEdit event, the Tag property of the DataGridRow, and created a style for the DataGridRow with a DataTrigger to put everything together.

First thing I did was to make sure my Model had an IsReadOnly property to latch onto, in the attached sample code, I did this by adding the property to one of the Customer in the Northwind database . 

CustomerReadOnlyProperty

Next, using a Trigger in my DataGridRow style, if the data item’s IsReadOnly property evaluates to “True” then I set the DataGridRow ‘s Tag to a string I can look for in my BeginningEdit event handler.  In the sample project attached and in the code snippets below, I used the string “ReadOnly”.  For a visual cue, I also set the HeaderTemplate to show an image to indicate that the row is locked. 

XAML Styles
  1. <!– Row Header Template to show a Locked icon.–>
  2. <DataTemplate x:Key="rowHeaderTemplate">
  3.     <StackPanel Orientation="Horizontal">
  4.         <Image x:Name="editImage" Source="Images/lock.gif" Width="16" Margin="1,0" />
  5.     </StackPanel>
  6. </DataTemplate>
  8. <!– DataGridRow Style –>
  9. <Style x:Key="ReadOnlyCheck" TargetType="{x:Type DataGridRow}">
  10.     <Style.Triggers>
  11.         <DataTrigger Binding="{Binding IsReadOnly}" Value="True">
  12.             <Setter Property="Tag" Value="ReadOnly" />
  13.             <Setter Property="HeaderTemplate" Value="{StaticResource rowHeaderTemplate}">
  14.             </Setter>
  15.         </DataTrigger>
  16.     </Style.Triggers>
  17. </Style>

 

CustomerReadOnlyVisual

Finally, in my BeginningEdit event handler for my DataGrid, I look at the Row going into Edit Mode, if its Tag property has been set to “ReadOnly” I cancel the event so it never makes it into edit mode.  This enforces the IsReadOnly property from my mode.

BeginningEdit Event Handler
  1. /// <summary>
  2. /// Event Handler for BeginningEdit Event of DataGrid.  If the Row entering into Edit Mode has a Tag set to "ReadOnly",
  3. /// cancel the edit.
  4. /// </summary>
  5. /// <param name="sender">Reference to the DataGrid</param>
  6. /// <param name="e">Instance of DataGridBeginningEditEventArgs</param>
  7. private void dataGrid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e)
  8. {
  9.     if (((DataGridRow)e.Row).Tag != null && ((DataGridRow)e.Row).Tag.ToString() == "ReadOnly")
  10.     {
  11.         e.Cancel = true;
  12.     }
  13. }

 

Sample Code Download

WPF Textbox Select All on Focus

/ By / In C#, WPF / 10 Comments

In WPF, the default behavior of the TextBox on focus is to put the cursor where it was the last time the TextBox had lost focus or if it hasn’t had focus yet, at the beginning. The users of the application wanted this to be changed so that when the TextBox got focus, all current text was selected. I found various ways to do this, but am putting this blog post together to get everything I ended up doing all in one place for easy access.
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