convert string to SqlDbType

Hi guys

I have below method:

public void  SP_Parameter(string[] InputParametername, int i, SqlDbType[] typein, string[] textBox)
        {
            i--;
            while (i > -1)
            {
                SqlParameter inparm = new SqlParameter(InputParametername[i], typein[i]);
                inparm.Value = textBox[i];
                inparm.Direction = ParameterDirection.Input;
                adap.SelectCommand.Parameters.Add(inparm);
                i--;
            }
//...

}

I want change it to:

public void  SP_Parameter(string[] InputParametername, int i, string[] typein, string[] textBox)
        {
            i--;
            while (i > -1)
            {
                SqlParameter inparm = new SqlParameter(InputParametername[i], (SqlDbType)typein[i]);
                inparm.Value = textBox[i];
                inparm.Direction = ParameterDirection.Input;
                adap.SelectCommand.Parameters.Add(inparm);
                i--;
            }
//...
}

what should I do to convet string to SqlDbType ?

Thank you