DataGridView ComboBoxCell is not showing values that are not from the list vb.net

Question

Hi all i have a combobox which is nicely populated from a binding source. So the problem is the column of the datagrid "Name" is only showing values which comes from the populated drop down list. Those values that is not the same as the droplist is shown empty. can someone tell me why? below is they code for the combobox. I cant printscreen but the describtion is like this. The LIst has 3 names : John , Jake, Jay but the colum has over 10 name , each in its respective cell. The problem when onload it is not showing the other names.

    Dim c4 As New DataGridViewComboBoxColumn()

    c4.HeaderText = "Name"
    c4.Name = "Name"
    c4.DataPropertyName = "Name"
    c4.DisplayMember = "NamesWithJ"
    c4.ValueMember = "NamesWithJ"
    c4.DisplayStyleForCurrentCellOnly = False
    c4.DisplayStyle = DataGridViewComboBoxDisplayStyle.Nothing
    c4.FlatStyle = FlatStyle.Standard
    c4.SortMode = DataGridViewColumnSortMode.Automatic
    c4.DataSource = AddtBndSrc
    c4.Width = 100
    Me.DataGrid.Columns.Add(c4)

And here is the code where i create the bindingsource and fill it with value. There is no error with the connection its showing perfectly. It just that the comboboxcolumn is showing null in some of the rows

                   Try

       con = New SqlConnection(strConnection)

      cib.Open()

        adoAAda = New SqlDataAdapter(StrAddNameQuery, con)

        adoAddtRs = New DataSet



        adoAAda.Fill(adoAddtRs)

        Dim tableAddt As DataTable = adoAddtRs.Tables(0)

        Dim colum As DataColumn = tableAddt.Columns(0)


        tableAddt.PrimaryKey = New DataColumn() {tableAddt.Columns(0)}

        AddtBndSrc.DataSource = adoAddtRs.Tables(0)


        con.close()

    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
    Try
        ' connection procedure
     con = New SqlConnection(strConnection)

       con.Open()

        adoPAda = New SqlDataAdapter(StrProductQuery, con)

        adoProductsRS = New DataSet



        adoPAda.Fill(adoProductsRS)

        Dim tableProduct As DataTable = adoProductsRS.Tables(0)

        Dim colum As DataColumn = tableProduct.Columns(0)


        tableProduct.PrimaryKey = New DataColumn() {tableProduct.Columns(0)}

        productBndSrc.DataSource = adoProductsRS.Tables(0)

        MsgBox(tableProduct.Columns(0).ColumnName.ToString)
       con.close

        datagridview.Datasource = productBndSrc

    Catch ex As Exception
        MsgBox(ex.Message)
    End Try

Answer 1

You want to merge values for combobox. Some are hardcoded into combo but are pulled from database. If so, you need to added the hardcoded values into datasource before binding to combo.

after following lines ADD THE CODE GIVEN BELOW.

    adoAAda.Fill(adoAddtRs)
    Dim tableAddt As DataTable = adoAddtRs.Tables(0)

'ADD YOUR HARD CODED NAMES TO DATASOURCE BEFORE BINDING

    Dim tableAddt As DataTable = adoAddtRs.Tables(0)

    Dim dr As DataRow = tableAddt.NewRow
    dr("NamesWithJ") = "My test 1"
    tableAddt.Rows.Add(dr)
    Dim dr1 As DataRow = tableAddt.NewRow
    dr("NamesWithJ") = "My test 2"
    tableAddt.Rows.Add(dr1)

Answer 2

It seems you are assigning the combobox bindingSource AddtBndSrc to the DataGridViewComboBoxColumn datasource. So if that colum had some items assigned they will be overwritten by the datasource.