C# Passing ComboBox to a function of separate class

Question

I have to list Companies in a desktop application again and again in diferent forms. That's why I wanted to make a common functions class to list companies in ComboBox on diferent forms. I am trying to pass ComboBox object to functions. But I am unable to do so. Following is the code which I am trying.

   CommonFunctions cmFunc = new CommonFunctions();
   ComboBox cmbx = cmbCompany;
   cmFunc.listCompanies(ComboBox cmbx);

cmbCompany is the ComboBox where companies will list.

Any suggestion or help highly appreciated.

Answer 1

If I understand correctly, you want to use a Delegate to fill a combo box on different forms.

The code below works and fills a ComboBox on a Windows Form, using a delegate. comboBox1 is a ComboBox on this form.

public partial class Form1 : Form
{
    delegate void FilComboDelegate(ComboBox comboBox);

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        FilComboDelegate fillComboHandler;

        fillComboHandler = FillCombo;

        fillComboHandler(comboBox1);
    }

    private static void FillCombo(ComboBox comboBox)
    {
        string [] companies = {"Company 1", "Company 2", "Company 3"};

        comboBox.Items.Clear();

        foreach(var company in companies)
            comboBox.Items.Add(company);
    }
}