Set the selected item of a dropdownlist to the matched string value in windows form c#

Question

I have a dropdown list on my windows form application that holds the manufacturer's names. Upon editing a given record, I want the user to be able to edit (change) the manufacturer as well. The rest of values are working fine and I can easily assign them to the text boxes where they will be edited and stored in the database again.

I have queried the dropdown list item (the manufacturer name that needs to be edited) from the database and now I want to show it as the selected item on the dropdown list. I used the following code to query a particular manufacturer based on id from the database and assign it to a string variable, manufacturerName.

DataTable dtMName = Products.SelectByManufacturerId(manufacturerId);
if (dtMName.Rows.Count > 0)
{
    foreach (DataRow item in dtMName.Rows)
    {
        string manufacturerName = item[0].ToString();
    }  
}

Upon debugging this piece of code, the string manfuacturerName hold the exact manufacturer name that I want to change in the dropdown list. Now, I want to mark this particular item as the selected item in the dropdown list. I want to pass it to the list so that it can select this particular manufacturer in the list.

So far, I have tried the following code but it is not working.

childEditProduct.cmbManufacturer.SelectedIndex = childEditProduct.cmbManufacturer.FindString(manufacturerName);

Note: I have marked the first item as the selectedIndex on childEditProduct form load. I have commented that code as well but nothing works. Is there any issue in my code or let me try something more effective that can solve my problem.

Answer 1

As I was loading the manufacturer dropdown list on my childForm load event using the following function:

private void LoadManufacturers()
{
    cmbManufacturer.Items.Clear();
    DataTable dtManufacturers = DataAccess.Select("select manufacturername from tblmanufacturer order by manufacturername asc");
    foreach (DataRow dr in dtManufacturers.Rows)
    {
        cmbManufacturer.Items.Add(dr[0].ToString());
    }
    //cmbManufacturer.SelectedIndex = 0;
}

While loading manufacturers on the page load event, I was also specifying the selected index of the dropdown list using the code cmbManufacturer.SelectedIndex = 0; which I commented out later.

Once done, I then recalculate (re-query) the selected manufacturer (which the user want to update) within the load event of the dropdown list like this:

private void frmChildEditProduct_Load(object sender, EventArgs e)
{
    LoadManufacturers(); // Calling the loadManufacturers function to load all the manufacturers to the dropdown list.

    string manufacturerID = lblManufacturerId.Text;

    DataTable dtMName = Products.SelectByManufacturerId(manufacturerID);
            if (dtMName.Rows.Count > 0)
            {
                foreach (DataRow manufacturer in dtMName.Rows)
                {
                    string manufacturerName = manufacturer[0].ToString();
                    cmbManufacturer.SelectedIndex = Convert.ToInt32(cmbManufacturer.FindStringExact(manufacturerName));
                }
            }
 }

And my problem was solved. Thanks for the support I got on Stackoverflow.