c# - 存储过程输出参数返回@Value

Question

在过去的一个小时里，我一直在为这件事苦苦挣扎，我确定我遗漏了一些小东西，我在 SQL Server 2008 和 C# 代码中有一个存储过程，我想返回我的存储过程的输出参数.

SQL:

Alter Procedure dbo.GetAssessment
    @UserID int,
    @AssessmentName varchar(255),
    @Score varchar(100) output,
    @Completed varchar(10) output,
    @DisplayName nvarchar(128) output,
    @Result varchar(2500) output
as
begin
        select @Score = A.Score, @Completed = A.Completed, @DisplayName = U.Displayname, @Result = A.Result 
        from Assessment A 
            inner join Users U
            on U.UserId = A.UserID
        where U.UserID = @UserId
        and AssessmentName = @AssessmentName

end
GO

C#

String SScore, SName, SResult, SComp;
            lblAsse.Text = Request.QueryString["AID"];

            InsertAssessment(lblAsse.Text, "No", 2, "N/A", "N/A");

            using (SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["SiteSqlServer"].ConnectionString))
            {
                SqlParameter outScore = new SqlParameter("@Score", SqlDbType.VarChar,100){ Direction = ParameterDirection.Output };
                SqlParameter outComp = new SqlParameter("@Completed", SqlDbType.VarChar,10){ Direction = ParameterDirection.Output };
                SqlParameter outName = new SqlParameter("@DisplayName", SqlDbType.NVarChar, 128) { Direction = ParameterDirection.Output };
                SqlParameter outResult = new SqlParameter("@Result", SqlDbType.VarChar,2500){ Direction = ParameterDirection.Output };              

                conn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.Connection = conn;
                cmd.CommandType = System.Data.CommandType.StoredProcedure;
                cmd.CommandText = "GetAssessment";
                cmd.Parameters.AddWithValue("@AssessmentName", lblAsse.Text);
                cmd.Parameters.AddWithValue("@UserId", 2);
                cmd.Parameters.Add(outScore);
                cmd.Parameters.Add(outComp);
                cmd.Parameters.Add(outName);
                cmd.Parameters.Add(outResult);
                cmd.ExecuteScalar();

                SScore = outScore.ToString();
                SName = outName.ToString();
                SResult = outResult.ToString();
                SComp = outComp.ToString();

                conn.Close();

                lblAsse.Text = SScore;`

输出:

@Score

我或我的代码可能有什么问题。请帮忙!

Answer 1

您只需要从输出参数中读出实际的值:

 SScore = outScore.Value;

.ToString() 不返回值 - 它返回参数的名称...

参见 MSDN documentation on SqlParameter了解更多详情。