C# Winform 获得下拉框 选中的值

     string PrintName = cmbPrinter.SelectedIndex.ToString();
            PrintName = cmbPrinter.SelectedItem.ToString(); //

            if (cmbPrinter.SelectedIndex != 0)
            {

            }

            string PrintName = "";
            PrintName = cmbPrinter.SelectedItem.ToString(); //"Gprinter GP-1124T0"
            var ss0 = cmbPrinter.Text; //Gprinter GP-1124T0"

            var  ss = cmbPrinter.SelectedIndex.ToString(); //  0