Copying Datagrid data to Clipboard through Context Menu

In my last post, I talked about adding context menu to Silverlight DataGrid. One thing that always frustrated our users was that they could not copy contents of a datagrid in our application to the clipboard.

Here is the example (clipboard is accessible through javascript only in IE, mind you):



I will make the full code available on Monday. Below, is a runthrough of how this was done.

There are plenty of examples on how to access the clipboard in Silverlight through javascript (for IE, anyways). Here is the code that I used, from Jeff Wilcox's example:

1:          public static void SetText(string text)

2:          {

3:              var clipboardData = (ScriptObject)HtmlPage.Window.GetProperty("clipboardData");

4:              if (clipboardData != null)

5:              {

6:                  bool success = (bool)clipboardData.Invoke("setData", "text", text);

7:                  if (!success)

8:                  {

9:                      HtmlPage.Window.Alert(ClipboardFailure);

10:                  }

11:              }

12:              else

13:              {

14:                  HtmlPage.Window.Alert("clipboard not available");

15:              }

16:          }

You can always ctrl+C to copy contents of a textbox or textblock to clipboard, but DataGrid does not allow that. To do this, I take the cell in context, loop through it's children recursively, and write out the contents of the child if it is TextBlock or TextBox:

1:          private static string GetText(UIElement uie)

2:          {

3:              string ret = string.Empty;

4:              if (uie != null)

5:              {

6:                  if (uie is TextBlock)

7:                      ret = (uie as TextBlock).Text;

8:                  else if (uie is TextBox)

9:                      ret = (uie as TextBox).Text;

10:                  else if (uie is Panel)

11:                  {

12:                      foreach (var element in (uie as Panel).Children)

13:                          ret += GetText(element);

14:                  }

15:              }

16:              return ret;

17:          }

Now, what if we want to have a menu command that copies whole row data? I have a generic serializer that takes the datacontext of the row as object and, using reflection, recursively creates a string representation:

   1:          private static string Serialize(object data)

   2:          {

   3:              if (data != null)

   4:              {

   5:                  var sb = new StringBuilder();

   6:                  var props = data.GetType().GetProperties();

   7:                  sb.Append(data.GetType().Name);

   8:                  foreach (var prop in props)

   9:                  {

  10:                      var o = prop.GetValue(data, null);

  11:                      sb.Append(Environment.NewLine).Append(prop.Name).Append(" = ");

  12:                      if (o == null || o is string || o is DateTime || o.GetType().IsPrimitive)

  13:                          sb.Append(o);

  14:                      else

  15:                          sb.Append(Serialize(o).Replace(Environment.NewLine, Environment.NewLine + "\t"));

  16:                  }

  17:                  return sb.ToString();

  18:              }

  19:              else return string.Empty;

  20:          }

How do we get to a reference to the cell? When context menu is requested, the DataGrid finds the cell where the right-click occurred, and keeps a reference to in a private field, to be used when the menu selection occurs. So the GetContextMenuContent method changes like so:

   1:          public virtual List<ContextMenuItemInfo> GetContextMenuContent(System.Windows.Browser.HtmlEventArgs e)

   2:          {

   3:              Point curr = new Point(e.OffsetX, e.OffsetY);

   4:              _CellInContext = null;

   5:              for (var i = 0; i < presenter.Children.Count; i++)

   6:              {

   7:                  var row = (DataGridRow)presenter.Children[i];

   8:                  if (ContextMenuInterceptor.IsPointWithinBounds(curr, row))

   9:                  {

  10:                      foreach (var col in Columns)

  11:                      {

  12:                          var cell = col.GetCellContent(row.DataContext).Parent as DataGridCell;

  13:                          if (cell != null && ContextMenuInterceptor.IsPointWithinBounds(curr, cell))

  14:                          {

  15:                              _CellInContext = cell;

  16:                              break;

  17:                          }

  18:                      }

  19:   

  20:                      foreach (ContextMenuItemInfo m in ContextMenuList)

  21:                          m.Tag = row;

  22:                      return ContextMenuList;

  23:                  }

  24:              }

  25:              return null;

  26:          }

And the HandleContextMenu actually handles some stuff instead of just raising an event:

   1:          public virtual void HandleContextMenuClick(object sender, ContextMenuClickEventArgs e)

   2:          {

   3:              switch (e.ClickedItem.Key)

   4:              {

   5:                  case CMD_COPY_ROW:

   6:                      Clipboard.SetText(Serialize(((DataGridRow)e.ClickedItem.Value).DataContext));

   7:                      break;

   8:                  case CMD_COPY_CELL:

   9:                      if (_CellInContext != null)

  10:                          Clipboard.SetText(GetText(_CellInContext.Content as UIElement));

  11:                      break;

  12:                  default:

  13:                      if (ContextMenuClicked != null)

  14:                          ContextMenuClicked(sender, e);

  15:                      break;

  16:              }

  17:          }

Both of these have worked very well for our application. Both "Copy Cell Content" and "Copy Row Data" are context menu commands in all our datagrids.