[SOLVED] How to fill a DataGridViewComboBoxColumn?

How to fill a DataGridViewComboBoxColumn?

Sorry if this is something that should be obvious, but this is my first project using VB.NET, and some things are still beyond me.

I'm trying to setup a combobox inside a DataGridView but I keep getting

System.ArgumentException: DatagridviewComboBoxCell value not valid

I've been googling this for 2 hours now and to me it seems I'm setting up thing correctly, but probably something is amiss.

Dim imageCol As DataGridViewImageColumn
Dim checkCol As DataGridViewCheckBoxColumn
Dim col As DataGridViewColumn
Dim comboCol As DataGridViewComboBoxColumn
Dim ds As DataSet
Dim som As New SomStructure
Dim somministrazioni() As SomStructure = {}

With dgvListaAttivita
    .Columns.Clear()
    .AutoGenerateColumns = False
    .ReadOnly = False
    .EditMode = DataGridViewEditMode.EditOnEnter
    .CausesValidation = False

    somministrazioni.Clear
    ds = getSomministrazioni(codevalue, Today())
    If ds IsNot Nothing Then
        For Each row As DataRow In ds.Tables(0).Rows
            som.idOspite = row(0)
            som.nomeOspite = row(1)
            som.descrizioneSomministrazione = row(2)
            som.idOperatore = row(3)
            som.nomeOperatore = row(4)
            som.preparata = False
            somministrazioni.Add(som)
        Next
    End If

    .DataSource = somministrazioni

    imageCol = New DataGridViewImageColumn
    imageCol.Width = 25
    imageCol.ImageLayout = DataGridViewImageCellLayout.Normal
    imageCol.Description = "delete"
    imageCol.Image = My.Resources.note
    .Columns.Add(imageCol)


    col = New DataGridViewColumn
    col.DataPropertyName = "descrizioneSomministrazione"
    col.HeaderText = "Somministrazione"
    col.ValueType = GetType(String)
    col.CellTemplate = New DataGridViewTextBoxCell
    col.AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill
    col.ReadOnly = True
    .Columns.Add(col)


    comboCol = New DataGridViewComboBoxColumn
    Dim dt As DataTable = dsOperatori.Tables(0)
    comboCol.DataSource = dt
    comboCol.DisplayMember = "display"
    comboCol.ValueMember = "idoperatore"
    comboCol.DataPropertyName = "idOperatore"
    comboCol.HeaderText = "Operatore"
    comboCol.ValueType = GetType(Integer)
    comboCol.CellTemplate = New DataGridViewComboBoxCell
    comboCol.Width = 150
    .Columns.Add(comboCol)


    checkCol = New DataGridViewCheckBoxColumn
    checkCol.DataPropertyName = "preparata"
    checkCol.HeaderText = "P."
    checkCol.ValueType = GetType(Boolean)
    checkCol.CellTemplate = New DataGridViewCheckBoxCell
    checkCol.Width = 20
    .Columns.Add(checkCol)

End With

As I understand it it should be like this:

comboCol.DataSource = dt
comboCol.DisplayMember = "display"
comboCol.ValueMember = "idoperatore"

specifies the datasource and key/display values of the comboboxes in the column

comboCol.DataPropertyName = "idOperatore"

Is the name of the column linked to both the DataSource of the DataGridView and the ValueMember of the ComboBox, and that should display different selections on different rows.

If I remove the DataPropertyName from the code I don't get the error anymore, but I also get empty comboboxes.

Solution

Try commenting out the template line:

comboCol = New DataGridViewComboBoxColumn
Dim dt As DataTable = dsOperatori.Tables(0)
comboCol.DataSource = dt
comboCol.DisplayMember = "display"
comboCol.ValueMember = "idoperatore"
comboCol.DataPropertyName = "idOperatore"
comboCol.HeaderText = "Operatore"
comboCol.ValueType = GetType(Integer)
'comboCol.CellTemplate = New DataGridViewComboBoxCell
comboCol.Width = 150
.Columns.Add(comboCol)