Is there a way to force a DataGridView to fire its CellFormatting event for all cells?

Question

We use the CellFormatting event to colour code cells in various grids all over our application.

We\'ve got some generic code which handles export to Excel (and print

Answer 1

A possible solution if you do want to reuse the formatting provided during the Cellformatting-event (e.g. the cellstyle-elements like fontbold and backgroundcolor). These cellstyles seem to be only available between the 'cellformatting' and 'cellpainting' events but not in the datagridview-cell's style itself..

Capture the cellstyles during the cellformatting-event with a second handler like this:

1. in the exportmodule add a shared list, array or dictionary to store the cellstyles:

   Dim oDataGridFormattingDictionary as  Dictionary(Of String, DataGridViewCellStyle) = nothing
   

2. initialize the dictionary and add a second handler to the datagridview in your printing or export-code. In vb.net something like this:

    oDataGridFormattingDictionary = New Dictionary(Of String, DataGridViewCellStyle)
    AddHandler MyDatagridviewControl.CellFormatting, AddressOf OnPrintDataGridView_CellFormatting
   

3. Add the code for the handler

   Private Sub OnPrintDataGridView_CellFormatting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs)
   If e.RowIndex > -1 AndAlso e.ColumnIndex > -1 AndAlso Not e.CellStyle Is Nothing Then
      If Not oDataGridFormattingDictionary Is Nothing andalso oDataGridFormattingDictionary.ContainsKey(e.RowIndex & "_" & e.ColumnIndex) = False Then
       oDataGridFormattingDictionary.Add(e.RowIndex & "_" & e.ColumnIndex, e.CellStyle)
      End If
   End If
   End Sub
   

4. Very important: to make sure the original cellformating-event (AND the second cellformatting-handler after that) are actually called you have to request the formattedvalue for each cell that you want to print (e.g.

   oValue = Datagridview.rows(printRowIndex).Cells(printColumnIndex).FormattedValue)
   

   !

5. When printing you can now check if the cell has formatting. E.g.:

   if not oDataGridFormattingDictionary is nothing andalso oDataGridFormattingDictionary.ContainsKey(printRowIndex & "_" & printColumnIndex) Then
   ... the cellstyle is accesible via:
   oDataGridFormattingDictionary(printRowIndex & "_" & printColumnIndex)
   end if 
   

6. at the end of the export or printcode remove the handler and set the dictionary to nothing

   RemoveHandler DirectCast(itemToPrint.TheControl, DataGridView).CellFormatting, AddressOf OnPrintDataGridView_CellFormatting
   oDataGridFormattingDictionary = nothing