Question

I have no idea where to start. i tried DataTable but it didn’t work.(This is an easy question 🙂 )

I tried everything

{
    var test = new DataTable();
    test.Columns.Add("test");
    test.TableName = "test";
    test.Columns.Add("test");

    comboBox1.DataSource = test.XXXX ;

}

Answer 1

Assuming you mean winforms, something like:

    DataTable test = new DataTable();
    test.TableName = "test";
    test.Columns.Add("foo", typeof(string));
    test.Columns.Add("bar", typeof(int));
    test.Rows.Add("abc", 123);
    test.Rows.Add("def", 456);

    ComboBox cbo = new ComboBox();
    cbo.DataSource = test;
    cbo.DisplayMember = "foo";
    cbo.ValueMember = "bar";

    Form form = new Form();
    form.Controls.Add(cbo);
    Application.Run(form);

(in particular, SelectedValue should give you the 123 and 456 – useful for ids, etc)