How to transfer from one Combobox to another (C#)

Question

The idea is, there is a Main Combobox, each with a customer from 4 different cities, I wanted to select a customer on Combobox, press the button and remove from this Combobox and insert in the corresponding city of it.

Summarizing: I want to take an item, remove it and put in the selected Combobox.

I tried using IF, since each Combobox starts with 0, but when adding to Combobox, it returns a value that contains something inside, but shows no text. (Example of what I tried)

if (cboClientes.SelectedIndex == 0 || cboClientes.SelectedIndex == 2 || cboClientes.SelectedIndex == 3 || 
{
    cboVarginha.Items.Add(cboClientes.SelectedIndex);
    cboClientes.Items.RemoveAt(cboClientes.SelectedIndex);
}

Answer 1

From what I understand, you want to select an item on ComboBox, push one button and move it to another ComboBox.

I set up a scheme here... I hope it fits.

Imagery:

Code Used:

        private void Form2_Load(object sender, EventArgs e)
        {
            for (int i = 1; i < 5; i++)
                comboBox1.Items.Add($"Item {i}");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (!comboBox1.SelectedIndex.Equals(-1))
            {
                comboBox2.Items.Add(comboBox1.SelectedItem);
                comboBox2.Sorted = true;

                Resultado.Text = $"O Elemento {(string)comboBox1.SelectedItem} foi transferido para o Destino";
                Resultado.Left = (Resultado.Parent.Width / 2) - (Resultado.Width / 2);

                comboBox1.Items.RemoveAt(comboBox1.SelectedIndex);                
                Resultado.Visible = true;
            }
        }

There is also the possibility to use the event SelectedIndexChanged of ComboBox and send it straight to Monday ComboBox at the time of selecting the Item in First.