Question

I would like to programmatically insert additional rows into a DataGrid (to act as subheadings). I have followed a number of articles online (namely option 3 from http://aspalliance.com/723) but they all result in the row being displayed correctly, but with no contents.

Here is the important part of the code I’m using:

private void MyDataGrid_ItemCreated(object sender, DataGridItemEventArgs e) {      // This method will create a subheading row if needed     if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)     {         // TableCell         TableCell tc = new TableCell();         tc.Controls.Add(new LiteralControl('foo'));         tc.ColumnSpan = e.Item.Cells.Count;          // DataGridItem         DataGridItem di = new DataGridItem(e.Item.ItemIndex + 1, 0, ListItemType.Item);         di.Height = new Unit(100, UnitType.Pixel);         di.CssClass = 'testClass';         di.Controls.Add(tc);          // DataGrid Table         DataGrid dg = (DataGrid)sender;         Table childTable = (Table)dg.Controls[0];         childTable.Rows.Add(di);     }        } 

This results in the following markup being generated in the correct place, but without the LiteralControl(‘foo’)

<tr class='testClass' style='height:100px;'> </tr> 

I would like to use this approach rather than manipulating the datasource itself. What could be going wrong?

Answer 1

Problem solved – somewhere in the 2500 lines of existing code-behind, something was hiding the first column, effectively removing my addition. Something to watch out for if anyone else has similar problems.

Edit – Here’s the code I’ve written to get round the problem in a reasonably generic way:

private void InsertDataGridRow(DataGrid dataGrid, int index, TableCell tc) {     DataGridItem di = new DataGridItem(index, 0, ListItemType.Item);      // Check which columns are visible     bool foundFirstVisibleColumn = false;     int numberOfVisibleColumns = 0;     foreach (DataGridColumn column in dataGrid.Columns)     {         if (column.Visible == true)         {             numberOfVisibleColumns++;             foundFirstVisibleColumn = true;         }          // Add dummy columns in the columns that are hidden         if (!foundFirstVisibleColumn)         {             di.Cells.Add(new TableCell());         }      }      tc.ColumnSpan = numberOfVisibleColumns;     di.Cells.Add(tc);     Table t = (Table)dataGrid.Controls[0];     t.Rows.Add(di); } 

And the above can be called something like this:

private void MyDataGrid_ItemCreated(object sender, DataGridItemEventArgs e) {     // This method will create a subheading row if needed     if (e.Item.ItemType == ListItemType.AlternatingItem || e.Item.ItemType == ListItemType.Item)     {         TableCell tc = new TableCell();         tc.Controls.Add(new LiteralControl('foo'));          InsertDataGridRow(             (DataGrid)sender,             e.Item.ItemIndex + 1,             tc);     }        }