Prevent Deletes when the DELete key is pressed in a DataGrid

You can do this by subclassing your DataGrid and overriding the ProcessDialogKey and PreProcessMessage methods to trap for the DEL key. I also add a new AllowDelete property to the DataGrid so you can toggle this functionality on and off.

Add this module level variable:

    ' Allow delete KEY flag.
    Private myAllowDelete As Boolean = False

Add this property:

    Public Property AllowDelete() As Boolean

        '
        ' Get/set property indicating if rows can be deleted.
        '

        Get
            AllowDelete = myAllowDelete
        End Get

        Set(ByVal theValue As Boolean)
            myAllowDelete = theValue
        End Set

    End Property

Add these methods:

    Public Overrides Function PreProcessMessage(_
           ByRef msg As System.Windows.Forms.Message) As Boolean
        '
        ' Allow/disallow deletes when the DEL key is pressed.
        '
        On Error Resume Next

        Dim keyCode As Keys = 
            CType((msg.WParam.ToInt32 And Keys.KeyCode), Keys)

        If keyCode = Keys.Delete And msg.Msg = WM_KEYDOWN Then
            If NOT myAllowDelete Then
                Return True
            End If
        End If

        Return MyBase.PreProcessMessage(msg)

    End Function

    Protected Overrides Function ProcessDialogKey( _
        ByVal keyData As System.Windows.Forms.Keys) As Boolean
        '
        ' Allow/disallow deletes when the DEL key is pressed.
        '
        On Error Resume Next

        If keyData = Keys.Delete Then
            If myHitTestInfo.Type = Me.HitTestType.RowHeader Then
                If NOT myAllowDelete Then
                    Return True
                End If
            End If
        End If

    End Function