VB.NET: How to avoid/deny DataGridView SelectionChange event from being handled?

Question

Here is my DataGridView:

Me.DGV_InvoiceContainers.MultiSelect = False
Me.DGV_InvoiceContainers.ReadOnly = True
Me.DGV_InvoiceContainers.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect
...

It contains one column and multiple rows. When clicking on a cell/row (different from the selected one), a logic test is done (under MouseDown Event handler) to be sure all conditions are fulfilled before changing selection. If not, SelectionChanged event may not be raised/handled, nothing may happen (Like when clicking on a Cancel button).

Is it possible?

Solved:

Private Sub DGV_InvoiceContainers_RowValidating(sender As Object, e As System.Windows.Forms.DataGridViewCellCancelEventArgs) Handles DGV_InvoiceContainers.RowValidating
        If Me.CurrentInvoice.IsOpen Then
            If Me.CurrentInvoice.ChangesHaveBeenMade Then
                Dim dialogResult As New DialogResult
                dialogResult = MessageBoxA.Show("Do you want to save changes?", "Question", _
                                                MessageBoxAAutoFill.Title, _
                                                MessageBoxAButtons.YesNoCancel, Library.MessageBoxAMode.Question, MessageBoxAButtonsAlignment.Right, _
                                                MessageBoxA.DialogResultButtons.Button1, {"&Save", "Do &not save", "&Cancel"})
                Select Case dialogResult
                    Case Windows.Forms.DialogResult.Yes
                        Me.Reader.Close()
                        Me.SaveChanges()
                        Me.InvoiceContainerSelectionAllowed = True
                    Case Windows.Forms.DialogResult.No
                        Me.Reader.Close()
                        Me.InvoiceContainerSelectionAllowed = True
                    Case Else
                        Me.InvoiceContainerSelectionAllowed = False
                End Select
            Else
                Me.Reader.Close()
                Me.InvoiceContainerSelectionAllowed = True
            End If
            '
            If Me.InvoiceContainerSelectionAllowed Then
                Me.DisposeInvoiceData()
            End If
        Else
            Me.InvoiceContainerSelectionAllowed = True
        End If

        If Not Me.InvoiceContainerSelectionAllowed Then
            e.Cancel = True
            Return
        End If
End Sub

Dan Dan · Accepted Answer · 2015-01-26T02:32:12

Yes, it is possible. You have to handle the RowValidating event and do your logic to check if you should allow the user to change row. If you want to cancel, use the eventArgs.Cancel property and set it to true.

Protected Overrides Sub OnRowValidating(e As DataGridViewCellCancelEventArgs)
If DialogResult.No = MessageBox.Show("Select a new record?", "New Record?", MessageBoxButtons.YesNo) Then
    e.Cancel = True
    Return
Else
    MyBase.OnRowValidating(e)
End If
End Sub

VB.NET: How to avoid/deny DataGridView SelectionChange event from being handled?

1 Answers