Question

I have a ComboBox with its DataSource set to an instance of a DataTable. When rows are added to the DataTable, they show in the ComboBox without additional code, but when a row is deleted, the ComboBox remains unchanged. A short summary of my code:

ComboBox selector = new ComboBox();
DataTable tbl = new DataTable();

PopulateTable()
{
    DataRow row1 = tbl.NewRow();
    row1["field1"] = 1;
    row1["field2"] = "Some Text";
    tbl.Rows.Add(row1);

    DataRow row2 = tbl.NewRow();
    row2["field1"] = 2;
    row2["field2"] = "More Text";
    tbl.Rows.Add(row2);
}

PopulateSelector()
{
    selector.DisplayMember = "field2";
    selector.ValueMember = "field1";
    selector.DataSource = tbl;
}

RemoveRow()
{
    tbl.Rows[0].Delete();
}

At this point, the ComboBox appears to be correct, but clicking it resets it to its previous data. The DataTable remains correct, deleting the row causes no problem in that instance, I just can’t make the ComboBox reflect the changes.

Answer 1

Try this:

PopulateSelector()
{
    selector.DataSource = null;
    selector.DisplayMember = "field2";
    selector.ValueMember = "field1";
    selector.DataSource = tbl;
}

RemoveRow()
{
    tbl.Rows[0].Delete();
    PopulateSelector()
}