i have some propblem in datagridviewcombobocolumn with custom datasource property in vb.net. when i add datasource it does not populate in datagridview combobox column it giving nothing.. any one please help me out from this problem... code comboboxcell: Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, ByVal initialFormattedValue As Object, ByVal dataGridViewCellStyle As DataGridViewCellStyle) ' Set the value of the editing control to the current cell value. MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, dataGridViewCellStyle) Dim ctl As ComboEditingControl = CType(DataGridView.EditingControl, ComboEditingControl) ctl.DropDownStyle = ComboBoxStyle.DropDown ctl.AutoCompleteSource = AutoCompleteSource.ListItems ctl.AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.Suggest If (Me.DataGridView.Rows(rowIndex).Cells(0).Value <> Nothing) Then Dim GetValueFromRowToUseForBuildingCombo As String = Me.DataGridView.Rows(rowIndex).Cells(0).Value.ToString() ctl.Items.Clear() Dim dt As New DataTable() Try dt = TryCast(DirectCast(Me.DataGridView.Columns(ColumnIndex), ComboColumn).DataSource, DataTable) Catch ex As Exception MsgBox("error") End Try If (dt Is Nothing) Then ctl.Items.Add("") Else Dim thing As DataRow For Each thing In dt.Rows ctl.Items.Add(thing(0).ToString) Next End If If Me.Value Is Nothing Then ctl.SelectedIndex = -1 Else ctl.SelectedItem = Me.Value End If ctl.EditingControlDataGridView = Me.DataGridView End If End Sub from code: Dim widgets As New WidgetDataHandler Dim obj = widgets.GetAllWigetTypes() Dim dt As New DataTable Dim ListofmyObjects As New List(Of widget_types)(obj) Dim objList As New cObjectToTable(Of widget_types)(ListofmyObjects) dt = objList.GetTable() Dim obj1 For Each obj1 In obj blPersons.Add(obj1) Next Dim col1 As New DataGridViewTextBoxColumn col1.DisplayIndex = 0 col1.DataPropertyName = "Id" col1.HeaderText = "Id" dgvi00.Columns.Add(col1) Dim col2 As New ComboColumn col2.DisplayIndex = 1 col2.SortMode = DataGridViewColumnSortMode.Automatic col2.HeaderText = "Name" col2.DataPropertyName = "Name" col2.ToolTipText = "Select something from my combo" Dim dst As New DataSet 'Dim dt1 As New DataTable 'dt1.Columns.Add(col2.HeaderText) 'For Each thing In dt.Rows ' MsgBox(thing(1).ToString) ' dt1.Rows.Add(thing(1).ToString) 'Next dst.Tables.Add(dt) col2.DataSource = dst.Tables(0) col2.DisplayMember = "Name" Me.dgvi00.Columns.AddRange(col2) dgvi00.DataSource = blPersons.BindingSource 'setup the bindings for the binding navigator Dim bn As New _365_Media_Library.BindingNavigatorWithFilter bn.Dock = DockStyle.Bottom bn.GripStyle = ToolStripGripStyle.Hidden Me.Controls.Add(bn) bn.BindingSource = blPersons.BindingSource note : its working good in standalone application regards and thanks sarva