C#如何调用SQLServer写的函数

--返回立方体的体积
create function fn_CnbicVolume(@CubeLength decimal(4,1),@CubeWidth decimal(4,1),@CubeHeight decimal(4,1))
returns decimal(12,3)
as
begin
return (@CubeLength * @CubeWidth * @CubeHeight)
end

SqlConnection conn = new SqlConnection(sqlConnStr);SqlCommand cmd = new SqlCommand("dbo.fn_CnbicVolume",conn);cmd.CommandType = CommandType.StoredProcedure;cmd.Parameters.Add("@CubeLength",SqlDbType.Decimal).Value = 12.3;cmd.Parameters.Add("@CubeWidth", SqlDbType.Decimal).Value = 4.5;cmd.Parameters.Add("@CubeHeight", SqlDbType.Decimal).Value = 4.5;cmd.Parameters.Add("@Result", SqlDbType.Decimal).Direction =  ParameterDirection.ReturnValue;conn.Open();cmd.ExecuteNonQuery();string str = cmd.Parameters["@Result"].Value.ToString();Console.WriteLine(str);