[ابو ليلى]

بعد اذن اخي الوادي 
هذه المشكلة واجهتني في يوم من الايام و و جدت الحل على الشبكة عبر اضافة كلاس خاصة تعيد تعريف القريد الافتراضي مع بعض التعديلات 
ساطرحها هنا مع طريقة التعامل معها
اولا في مشروعك قم باضافة كلاس جديد و سميه APSDataGridView
بعد ذلك قم بنسخ هذا الكود و ضعه داخل الكلاس

كود :

Imports System.Windows.Forms
Namespace APS.Windows.Forms
   ' Derived DataGridView that takes care of the details so combo boxes use type-in (editable) mode.
   Public Class APSDataGridView
       Inherits System.Windows.Forms.DataGridView
       ' It seems to generate the delegate [event]EventHandler automatically from the event declaration...
       'Public Delegate Sub ComboBoxItemNotInListEventHandler(ByVal dgv As DataGridView, ByVal cbo As ComboBox, ByVal cboColumn As DataGridViewComboBoxColumn, ByVal e As DataGridViewCellValidatingEventArgs)
       Public Event ComboBoxItemNotInList(ByVal dgv As DataGridView, ByVal cbo As ComboBox, ByVal cboColumn As DataGridViewComboBoxColumn, ByVal e As DataGridViewCellValidatingEventArgs)
       ' Constructor
       Public Sub New()
           MyBase.New()
       End Sub

       ' This makes combo boxes "editable" so you can type in them. See the DataGridView FAQ.
       Protected Overrides Sub OnEditingControlShowing(
       ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs)
           Dim dgv As DataGridView = Me 'sender
           If (TypeOf e.Control Is ComboBox) Then
               Dim cbo As ComboBox = DirectCast(e.Control, ComboBox)
               ' Optional: http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=254131&SiteID=1
               'cbo.AutoCompleteMode = AutoCompleteMode.SuggestAppend
               'cbo.AutoCompleteSource = AutoCompleteSource.ListItems
               ' This makes it a type-in combo box
               cbo.DropDownStyle = ComboBoxStyle.DropDown
               ' Adjust the ComboBox behavior:
               AddHandler cbo.PreviewKeyDown, New PreviewKeyDownEventHandler(AddressOf comboBox_PreviewKeyDown)
               ' (Thanks to Ying Liu, Microsoft SupportSmile
               dgv.NotifyCurrentCellDirty(True)
           End If
           ' Call registered event handlers...
           MyBase.OnEditingControlShowing(e)
       End Sub

       ' Validate typed-in values...
       Protected Overrides Sub OnCellValidating(ByVal e As DataGridViewCellValidatingEventArgs)
           Dim dgv As DataGridView = Me 'sender
           If Not TypeOf (dgv.EditingControl) Is ComboBox Then
               ' Every control path should call MyBase.OnCellValidating
               MyBase.OnCellValidating(e)
           Else
               Dim cbo As ComboBox = dgv.EditingControl
               If (cbo Is Nothing) Then
                   MyBase.OnCellValidating(e)
                   Exit Sub ' cbo is Nothing if the user did not edit the cell
               End If
               ' This does two things:
               ' (1) This makes the combo box case-insensitive.
               ' (2) You have to force the SelectedIndex when using type-in mode or it will not properly recognize the change
               ' This little gem comes from
               ' http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=254131&SiteID=1
               cbo.SelectedIndex = cbo.FindStringExact(cbo.Text.Trim)
               ' You could customize the handling below on a column-by-column basis...
               If cbo.SelectedIndex = -1 Then ' The item wasn't in the list...
                   ' Is it because the value is empty?
                   If (cbo.Text.Trim = String.Empty) Then
                       ' We assume that it's okay to have an empty value here...
                       ' Let the user delete the value...
                       ' Don't Raise Event ComboBoxItemNotInList...
                   Else
                       ' A value was entered but it was not in the list...
                       Dim cboColumn As DataGridViewComboBoxColumn = dgv.Columns(e.ColumnIndex)
                       RaiseEvent ComboBoxItemNotInList(dgv, cbo, cboColumn, e)
                       If (e.Cancel = True) Then
                           ' How do we cancel a value if it creates a new row?
                           Beep() ' Set a breakpoint here
                           ' ? force dgv value to empty???
                           ' Don't return yet - we still need to call the base class event handler
                       Else
                           ' If the user added the item to the combo box, we need to accept the new value...
                           ' Again, from http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=254131&SiteID=1
                           cbo.SelectedIndex = cbo.FindStringExact(cbo.Text.Trim)
                       End If
                   End If
               End If
           End If
           ' Call the base class handler and user handlers...
           MyBase.OnCellValidating(e)
       End Sub
       Protected Shared Sub comboBox_PreviewKeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.PreviewKeyDownEventArgs)
           ' There is a glitch if you are using a ComboBox either in a DataGridView or standalone.
           ' If you open the ComboBox dropdown but then type a value and press ENTER, the value is lost.
           ' This error does not appear if you press TAB.
           ' This is the workaround.
           If (e.KeyCode = Keys.Enter) Then
               Dim cbo As ComboBox = sender
               If cbo.DroppedDown Then
                   cbo.DroppedDown = False
               End If
           End If
           ' Allow the ESC key to cancel changes even if AutoComplete mode has been active.
           If (e.KeyCode = Keys.Escape) Then
               Dim cbo As ComboBox = sender
               ' I don't know why this works, but it does:
               cbo.Text = ""
           End If
       End Sub
   End Class
End Namespace

الان قم بحفظ المشروع  ثم قم بعملية Build للمشروع و ستظهر لديك قريد جديدة في صندوق الادوات باسم APSDataGridView
قم باضافتها الى المشروع و تعامل معها بالشكل الافتراضي
الان في Form1 
عرف مايلي

كود :

   Enum CBO_MODE
       NORMAL = 0
       EDITABLE = 1
       EDITABLE_WITH_NOTIFYCURRENTCELLDIRTY = 2
   End Enum
   Const ALLOW_ADDS As Boolean = True
   Private MODE As CBO_MODE = CBO_MODE.EDITABLE_WITH_NOTIFYCURRENTCELLDIRTY

الان كل ما تحتاج اليه هو معالجة الحدثين التاليين كما يلي

كود :

   Private Sub ApsDataGridView1_EditingControlShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs) Handles ApsDataGridView1.EditingControlShowing
       ' هنا تستطيع التحكم اذا كان العنصر قابل للتعديل اما لا
       If e.CellStyle.Tag = "editable" Then
           Dim dataGridView1 As DataGridView = CType(sender, DataGridView)
           If (TypeOf (e.Control) Is ComboBox) Then
               Dim cb As ComboBox = CType(e.Control, ComboBox)
               If (Not cb Is Nothing) Then
                   cb.DropDownStyle = ComboBoxStyle.DropDown
                   If (MODE = CBO_MODE.EDITABLE_WITH_NOTIFYCURRENTCELLDIRTY) Then
                       dataGridView1.NotifyCurrentCellDirty(True)
                   End If
               End If
           End If
       End If

   End Sub

كود :

   Private Sub ApsDataGridView1_CellValidating(sender As Object, e As DataGridViewCellValidatingEventArgs) Handles ApsDataGridView1.CellValidating
       Dim dataGridView1 As DataGridView = CType(sender, DataGridView)
       If (TypeOf dataGridView1.Columns(e.ColumnIndex) Is DataGridViewComboBoxColumn) Then
           Dim comboBoxColumn As DataGridViewComboBoxColumn = dataGridView1.Columns(e.ColumnIndex)
           If (Not comboBoxColumn.Items.Contains(e.FormattedValue)) Then
               If (ALLOW_ADDS) Then
                   Beep() ' تم اضافة صوت يمكنك الغائه
                   comboBoxColumn.Items.Add(e.FormattedValue)
               Else
                   ' هنا للاغلاق
                   e.Cancel = True
               End If
           End If
       End If
   End Sub