从C#中的存储过程获取返回值

CREATE PROCEDURE GetReturnValue
    @InputParam INT,
    @OutputParam INT OUTPUT
AS
BEGIN
    -- 存储过程的逻辑
    SET @OutputParam = @InputParam * 2
END

using System;
using System.Data.SqlClient;

class Program
{
    static void Main(string[] args)
    {
        string connectionString = "Data Source=localhost;Initial Catalog=YourDatabase;Integrated Security=True";
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlCommand command = new SqlCommand("GetReturnValue", connection);
            command.CommandType = System.Data.CommandType.StoredProcedure;

            SqlParameter inputParam = new SqlParameter("@InputParam", SqlDbType.Int);
            inputParam.Value = 10;
            command.Parameters.Add(inputParam);

            SqlParameter outputParam = new SqlParameter("@OutputParam", SqlDbType.Int);
            outputParam.Direction = System.Data.ParameterDirection.Output;
            command.Parameters.Add(outputParam);

            connection.Open();
            command.ExecuteNonQuery();

            int returnValue = (int)outputParam.Value;
            Console.WriteLine("Return value: " + returnValue);
        }
    }
}