How to iterate through a combobox's items and match a string function?

A better idea just count the element in the combo box and iterate through their index .

private bool checkid(string str )

        {

            bool k = false;

            for (int i = 0; i < cmbmsiid.Items.Count;i++ )

            {

                if (cmbmsiid.Items[i].ToString() == str)

                {

                    k = true;

                    break;

                }

            }

            return k;

        }