VB.NET: Error adding multiple rows in a DataGridView (not bound to a DataTable)

Dimitri Backaert

Hi, I'm having problems adding multiple rows to a DataGridView, on the Load-event of a Windows Application Form. Adding one record doesn't cause a problem, but when adding the second record (using the identical code), an Exception is thrown. Here's my code so far (VB.NET 2008):

Private Sub BWMFPForm\_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    Dim dgvRow As New DataGridViewRow
    Dim dgvCell As DataGridViewCell
    Dim dgvButton As DataGridViewImageColumn
    Dim column As DataGridViewColumn

    'Disable sorting for all Columns
    For Each column In DataGridViewBrochures.Columns
        column.SortMode = DataGridViewColumnSortMode.NotSortable
    Next

    'Add Record
    'Column 1: Machine
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "Aficio MP 4000 / Aficio MP 5000"
    dgvRow.Cells.Add(dgvCell)
    'Column 2: Speed
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "40 PPM / 50 PPM"
    dgvRow.Cells.Add(dgvCell)
    'Column 3: Language
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "Nederlands"
    dgvRow.Cells.Add(dgvCell)
    'Column 4: Image Print
    dgvButton = New DataGridViewImageColumn
    dgvButton.Image = Drawing.Image.FromFile("D:\\DEVPROJECTS\\MarketingTouchScreen\\TouchScreen\\images\\Print\_Icon.jpg")
    dgvButton.ReadOnly = True
    dgvButton.ImageLayout = DataGridViewImageCellLayout.Normal
    DataGridViewBrochures.Columns.Add(dgvButton)
    'Add the Row
    DataGridViewBrochures.Rows.Add(dgvRow)

    'Add Record
    'Column 1: Machine
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "Aficio MP 4000 / Aficio MP 5000"
    dgvRow.Cells.Add(dgvCell)
    'Column 2: Speed
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "40 PPM / 50 PPM"
    dgvRow.Cells.Add(dgvCell)
    'Column 3: Language
    dgvCell = New DataGridViewTextBoxCell()
    dgvCell.Value = "Nederlands"
    dgvRow.Cells.Add(dgvCell)
    'Column 4: Image Print
    dgvButton = New DataGridViewImageColumn
    dgvButton.Image = Drawing.Image.FromFile("D:\\DEVPROJECTS\\MarketingTouchScreen\\TouchScreen\\images\\Print\_Icon.jpg")
    dgvButton.ReadOnly = True
    dgvButton.ImageLayout = DataGridViewImageCellLayout.Normal
    DataGridViewBrochures.Columns.Add(dgvButton)

Jay Royall

When adding your second record you are still using the same DataGridViewRow as for the first record. You will need to use the new keyword on dgvRow before adding cells to it. Also, in future it is helpful if you include any error messages in your post :)

Kschuler

For future reference, adding the text of the exception is always helpful. However from you're code I'm guessing it's something like "...row already exists in grid." ...or something like that. You're adding the same row object to the grid twice. You need a new row object the second time around. Otherwise all you are doing is updating the data in the first row you added. Hope this helps.

Dimitri Backaert

Hi Liqz, Thanks! That did the trick. I'll keep in mind that next time, I'll include the error message. Cheers.

Jay Royall

You're welcome :)