Programmatically select an item in combobox by using its ValueMember property

Question

I have a method that gets the ComboBox object and the query to be loaded on its items.

The method also asks for 2 other items:

1.The DB table's column name and sets it into the Combobox's DisplayMember property

2.The id of each record under that DB table column name and sets it into the Combobox's ValueMember property

public void DatabaseColumnRecordsToCombobox(ComboBox cbx, String query, String displayMember, String valueMember)
{
    try
    {
        cmd = new MySqlCommand(query, connection);
        da = new MySqlDataAdapter(cmd);
        tbl = new DataTable();
        da.Fill(tbl);
        cbx.DataSource = tbl;
        cbx.DisplayMember = displayMember;
        cbx.ValueMember = valueMember;
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
    finally
    {
        this.CloseConnection();
    }
}

I use the method by creating a query with 2 columns, the Id and its corresponding Name. And storing it in the ComboBox's DisplayMember and ValueMember:

DatabaseColumnRecordsToCombobox(cmbSupplier, "SELECT Id, Supplier_Name FROM Supplier WHERE Enable_Flag=1 ORDER BY Supplier_Name", "Supplier_Name", "Id");

I apologize for the long introduction, I just want you all to understand how my program works before telling my problem. So the problem is how do I select the default item of DataGridView by using the ComboBox's ValueMember property?

All I know in programatically selecting an item is by using cmbCategory.SelectedItem = "Supplier A" but what I need is to select by using the ValueMember. This way I can set the default item by Id.

score 3 · Accepted Answer · answered Apr 26 '16 at 15:34

Just use SelectedValue instead:

comboBox1.SelectedValue = "2";

A very simple example just to show what i mean:

        DataTable dt = new DataTable();
        dt.Clear();
        dt.Columns.Add("Id");
        dt.Columns.Add("Supplier_Name");
        DataRow r = dt.NewRow();
        r["Id"] = "1";
        r["Supplier_Name"] = "Supplier A";
        dt.Rows.Add(r);
        r = dt.NewRow();
        r["Id"] = "2";
        r["Supplier_Name"] = "Supplier B";
        dt.Rows.Add(r);
        r = dt.NewRow();
        r["Id"] = "3";
        r["Supplier_Name"] = "Supplier C";
        dt.Rows.Add(r);

        comboBox1.DataSource = dt;
        comboBox1.DisplayMember = "Supplier_Name";
        comboBox1.ValueMember = "Id";

        //This will set the ComboBox to "Supplier B"
        comboBox1.SelectedValue = "2";

It worked! Thank you very much! But just want to know if it's okay to use an integer for combobox1.SelectedValue? e.g. `comboBox1.SelectedValue = 1`. I used an integer and it still worked, just don't know why this went okay. By the way, I love you man! #nohomo — Harambe Attack Helicopter, Apr 26 '16 at 15:48
Ha ha no problem man! An integer should work as well since its an object type. You should be able to use the same type as the type you have in your ValueMember. — MrApnea, Apr 27 '16 at 05:19

Programmatically select an item in combobox by using its ValueMember property

1 Answers1