C#通过执行sql语句的方式执行存储过程，得到输出参数

一般情况下我们是这样执行存储过程的，下面方式也可以获取返回值

 public static DataTable ExecuteStoredPro(string storeName, out int resultcount, string title, int pageindex, int pagesize)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.CommandText = storeName;
                    SqlParameter[] para ={
                                     new SqlParameter("@title",SqlDbType.Int),
                                     new SqlParameter("@pageindex",SqlDbType.Int),
                                     new SqlParameter("@pagesize",SqlDbType.Int),
                                     new SqlParameter("@result_value",SqlDbType.Int)

            };

                    para[0].Value = title;
                    para[1].Value = pageindex;
                    para[2].Value = pagesize;
                    para[3].Direction = ParameterDirection.Output; //设定参数的输出方向  

                    cmd.Parameters.AddRange(para);// 将参数加入命令对象  
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    DataTable dt = new DataTable();
                    adapter.Fill(dt);

                    resultcount = Convert.ToInt32(cmd.Parameters[3].Value);


                    return dt; 
                   

                }
            }

        }

但是在一些情况下，我们不能像上面直接通过存储过程名执行存储过程，我们可以像执行sql语句一样执行存储过程，这样获取返回值也有些区别，如下

 public string FileApprove(FileApproveMetadata data)
        {
            SqlParameter para = new SqlParameter() { ParameterName = "@error",DbType= DbType.String, Size=500};
            para.Direction = ParameterDirection.Output;//这个必须加，sql语句中的output也要加

            SqlParameter[] param = { new SqlParameter() { ParameterName= "@projectId", Value=data.ProjectId },
                new SqlParameter() { ParameterName = "@taskId", Value = data.TaskId },
                new SqlParameter() { ParameterName = "@subTaskId", Value = data.SubTaskId },
                new SqlParameter() { ParameterName = "@create_EmpId", Value = data.Create_EmpId },
                new SqlParameter() { ParameterName = "@fileIds", Value = data.FileIds },
                new SqlParameter() { ParameterName = "@fileapprovers", Value = data.Fileapprovers },
                new SqlParameter() { ParameterName = "@remark", Value = data.Remark },para};
           
           //直接写执行语句
            CurrentRepository.ExecuteSql(@"exec [proc_Flow_AddFileApprove] @projectId,@taskId,@subTaskId,@create_EmpId,@fileIds,
            @fileapprovers,@remark,@error output", param);


            return para.Value.ToString();
        }