Question

How can I set up my WPF datagrid to sort on multiple columns similar to having two sortable columns, clicking on the header of the first column for a primary sort and then SHIFT clicking on the header of the second column for a secondary sort. I would like the multiple column sort to happen automatically when the user clicks on the header of the first column without having to SHIFT click on the second column header. Is there a way to do this entirely in the xaml? If not how can I do this in the code behind? Currently using VB.Net but a C# snippet is acceptable if you have one. Thanks!

Answer 1

You can do this by adding System.ComponentModel namespace like this:

xmlns:scm="clr-namespace:System.ComponentModel;assembly=WindowsBase"

then inside the CollectionViewSource XAML add new SortDescriptions like this:

<CollectionViewSource … >
            <CollectionViewSource.SortDescriptions>
                <scm:SortDescription PropertyName="Column1"/>
                <scm:SortDescription PropertyName="Column2"/>
            </CollectionViewSource.SortDescriptions>
</CollectionViewSource>

this will sort datagrid on column1,column2.

Edit:

also doing this using C# code behind is pretty easy :

    private void btnSort_Click(object sender, RoutedEventArgs e)
    {
        System.Windows.Data.CollectionViewSource myViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("The_ViewSource_Name")));
        myViewSource.SortDescriptions.Add(new SortDescription("Column1", ListSortDirection.Ascending));
        myViewSource.SortDescriptions.Add(new SortDescription("Column2", ListSortDirection.Ascending));
    }

Edit2:

Workaround can be made to catch the column header left mouse click event and prevent the grid from sort on that column like this:

• Disable grid property named
  CanUserSortColumns

• Add this code to the grid
  PreviewMouseLeftButtonUp event :

  private void myDataGrid_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
  {
      DependencyObject dep = (DependencyObject)e.OriginalSource;
      while ((dep != null) &&
      !(dep is DataGridCell) &&
      !(dep is DataGridColumnHeader))
      {
          dep = VisualTreeHelper.GetParent(dep);
      }
  
      if (dep == null)
          return;
  
      if (dep is DataGridColumnHeader)
      {
          DataGridColumnHeader columnHeader = dep as DataGridColumnHeader;
          // check if this is the wanted column
          if (columnHeader.Column.Header.ToString() == "The_Wanted_Column_Title")
          {
              System.Windows.Data.CollectionViewSource myViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("myViewSource")));
              myViewSource.SortDescriptions.Clear();
              myViewSource.SortDescriptions.Add(new SortDescription("Column1", ListSortDirection.Ascending));
              myViewSource.SortDescriptions.Add(new SortDescription("Column2", ListSortDirection.Ascending));
          }
          else
          {
              //usort the grid on clicking on any other columns, or maybe do another sort combination
              System.Windows.Data.CollectionViewSource myViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("myViewSource")));
              myViewSource.SortDescriptions.Clear();
          }
  
      }
  }
  

You can modify and expand this code to achieve your requirements.