DataGridView bound to list(of T) change column type

Question

I have a datagridview the is bound to a List(of T).

Private BodyComponents As New List(Of BodyComponent)
Private BodyBinding As BindingSource


Public Sub New()

    ' This call is required by the designer.
    InitializeComponent()


    ' Set the bindingsource
    BodyBinding = New BindingSource(BodyComponents, Nothing)

    ' Add any initialization after the InitializeComponent() call.
    dgvBodyOverview.DataSource = BodyBinding

    ....

All the items in the list represent a object with multiple properties, one of these is material As String. I have a large list of available materials where the user should be able to choose from. How can I make this available in the datagridview as drop-down box?

Info: The materials are read at run-time when the dialog is opened and not hardcoded.

Answer 1

You can't change the column types, so after the columns are created replace the Material one with a new DataGridViewComboBoxColumn you created:

dgv1.DataSource = ...

Dim cbo = New DataGridViewComboBoxColumn()
Dim oldCol = dgv1.Columns("Material")
' copy or set prop values
cbo.HeaderText = oldCol.HeaderText
cbo.Name = oldCol.Name
cbo.DataSource = MaterialsList
cbo.DataPropertyName = "Material"

' replace the column
dgv1.Columns.Remove(oldCol)
dgv1.Columns.Add(cbo)
' cant set the Display Index until it is in the DGV
cbo.DisplayIndex = oldCol.DisplayIndex

---

In cases where you need the column to display one thing but save something like an Id to the DGV's DataSource, you'd do that thru the combo column's DataSource.

Use either a DataTable query result which contains the Id and text you want to show, or a simple List those Name-Value pairs:

cbo.DataSource = Materials              ' == a DT or List of Name-Id
cbo.DisplayName = "MaterialName"        ' col or prop name to show
cbo.ValueMember = "Id"                  ' value to save 

The datatype of the ValueMember needs to match that of the column it maps to in the data source (cbo.DataPropertyName)