Hi Paul,

Thank you for your prompt reply!

Could you tell me how you bind the DataGridViewComboBoxColumn?

If you bind the DataGridViewComboBoxColumn to a data source and set the
ValueMember and DisplayMember properties, the DataGriedViewComboBoxCell
should show the text of the corresponding DisplayMember, not value of the
ValueMember.

I will illustrate this with an example. Create a WinForm application
project and add a DataGridView and a Button on the form. Add a
DataGridViewComboBoxColumn into the DataGridView control. In the Form load
event handler, create a DataTable with two columns named ID and Name and
add some rows into this DataTable and bind the DataGridViewComboBoxColumn
in the DataGridView to the DataTable.

In the Button Click event handler, set the current cell's value to a
specified value.

The following is the sample code:

private void Form1_Load(object sender, EventArgs e)
{
           this.dataGridView1.RowCount = 3;
                     
           DataTable lookup = new DataTable();
           DataColumn col = new DataColumn("ID", typeof(Int32));
           lookup.Columns.Add(col);
           col = new DataColumn("Name", typeof(string));
           lookup.Columns.Add(col);
           DataRow row = lookup.NewRow();
           row[0] = 1;
           row[1] = "aa";
           lookup.Rows.Add(row);
           row = lookup.NewRow();
           row[0] = 2;
           row[1] = "bb";
           lookup.Rows.Add(row);                      
       
           // bind the DataGridViewComboBoxColumn to the DataTable
           (this.dataGridView1.Columns[0] as
DataGridViewComboBoxColumn).DataSource = lookup;
           (this.dataGridView1.Columns[0] as
DataGridViewComboBoxColumn).ValueMember = "ID";
           (this.dataGridView1.Columns[0] as
DataGridViewComboBoxColumn).DisplayMember = "Name";
}

private void button1_Click(object sender, EventArgs e)
{
           this.dataGridView1.CurrentCell.Value = 2; // the current cell's
value becomes 2 and the text displayed in the current cell becomes "bb"
}

in the eventhandler for the EditingControlShowing event - ComboBox c =
e.Control as ComboBox

To get the hosted ComboBox in the DataGridViewComboBoxCell, we usually
handle the EditingControlShowing event of the DataGridView. But I don't
think you need to get the hosted ComboBox in order to get the valid values
for the DataGridViewComboBoxCell.

Hope this helps.
If you have any question, please feel free to let me know.

Sincerely,
Linda Liu
Microsoft Online Community Support