title: DataGridViw ComboBox Column Event SelectedindexChanged
body: <p>in tha datagridview there are five columns as </p>
  
  <p>1 -Product ID       2- Product Name  3-Description   4-Price   and the fifth one is <br>
  select-country which  is comboboxcolumn<br>
  </p>
  
  <pre><code>DataGridView1.Columns.Add("ID", "Product ID")
      DataGridView1.Columns.Add("Name", "Product Name")
      DataGridView1.Columns.Add("Description", "Description")
      DataGridView1.Columns.Add("Price", "Price")
  
  
   Dim datagridviewcol As New DataGridViewComboBoxColumn
      datagridviewcol.Items.Add("Pak")
      datagridviewcol.Items.Add("KUI")
      datagridviewcol.Name = "Select"
      DataGridView1.Columns.Add(datagridviewcol)
  </code></pre>
  
  <p>i add handler selectedindexchanged in datagridview editingcontrolshowing like </p>
  
  <pre><code> Private Sub DataGridView1_EditingControlShowing(ByVal sender As System.Object, ByVal e           As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
      If Me.DataGridView1.CurrentCell.ColumnIndex = 4 Then
          Dim cb As ComboBox = CType(e.Control, ComboBox)
          AddHandler cb.SelectedIndexChanged, AddressOf ComboBox_SelectedIndexChanged
  
      End If
  
  End Sub
  </code></pre>
  
  <p>the selectedindexchanged event like </p>
  
  <pre><code>Private Sub ComboBox_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
      If CType(sender, ComboBox).SelectedIndex = 0 Then
          MessageBox.Show("PAK")
      Else
          MessageBox.Show("KUI")
      End If
  
  End Sub
  </code></pre>
  
  <p>it works well but if you are on datagridview row # 4 then the messagebox 4 times prompt you 
  let if you select "PAK" from 15th row then messagebox will prompt 15 times i need only 1 time it to prompt.</p>
  
  <p>help me. so that independent of row the messagebox show 1 time not as many times as the row number.</p>