SqlDataAdapter输出变量问题C＃

Question

我不清楚如何在使用C＃时为输出变量格式化SqlDataAdapter

错误信息：

索引（从零开始）必须大于或等于零且小于参数列表的大小。

代码示例（存储过程正常）

        private DataTable updateOrdEodHold(DataTable tb, out string mnpft, out string authld, out string trd, out string hld, out string extnow)
    {
        // start the connection string
        string connstr = ConfigurationManager.ConnectionStrings["LocalSqlServer"].ConnectionString;
        SqlConnection myConn = new SqlConnection(connstr);
        // declare Symbol and assign for Errors Catch Exception
        string Symbol = "";
        string sqlComm = "dbo.UpdateOrdEodHold";
        DataTable HoldVals = new DataTable();
        SqlDataAdapter dataAdp = new SqlDataAdapter(sqlComm, myConn);
        dataAdp.SelectCommand.CommandType = CommandType.StoredProcedure;
        string ticker = (string)Convert.ToString(tb.Rows[0]["Ticker"]);
        // update Symbol for Catch ex
        Symbol = ticker.ToString();
        String company = (string)Convert.ToString(tb.Rows[0]["Company"]);
        String avgprofit = (string)Convert.ToString(tb.Rows[0]["AvgProfit"]);
        String extdte = (string)Convert.ToString(tb.Rows[0]["ExitDate"]);
        dataAdp.SelectCommand.Parameters.Clear();
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@ticker", SqlDbType.VarChar, 10));
        dataAdp.SelectCommand.Parameters["@ticker"].Value = (string)ticker.ToString();
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@company", SqlDbType.VarChar, 25));
        dataAdp.SelectCommand.Parameters["@company"].Value = (string)company.ToString();
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@avgpft", SqlDbType.VarChar, 10));
        dataAdp.SelectCommand.Parameters["@avgpft"].Value = (string)avgprofit.ToString();
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@mnpft", SqlDbType.VarChar, 10));
        dataAdp.SelectCommand.Parameters["@mnpft"].Direction = ParameterDirection.Output;
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@authld", SqlDbType.VarChar, 6));
        dataAdp.SelectCommand.Parameters["@authld"].Direction = ParameterDirection.Output;
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@hld", SqlDbType.VarChar, 6));
        dataAdp.SelectCommand.Parameters["@hld"].Direction = ParameterDirection.Output;
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@trd", SqlDbType.VarChar, 6));
        dataAdp.SelectCommand.Parameters["@trd"].Direction = ParameterDirection.Output;
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@extnow", SqlDbType.VarChar, 6));
        dataAdp.SelectCommand.Parameters["@extnow"].Direction = ParameterDirection.Output;
        dataAdp.SelectCommand.Parameters.Add(new SqlParameter("@extdte", SqlDbType.VarChar, 15));
        dataAdp.SelectCommand.Parameters["@extdte"].Value = (string)extdte.ToString();
        dataAdp.Fill(HoldVals);
        mnpft = HoldVals.Rows[0]["MinProfit"].ToString();
        authld = HoldVals.Rows[0]["AutoHold"].ToString();
        trd = HoldVals.Rows[0]["Trade"].ToString();
        hld = HoldVals.Rows[0]["Hold"].ToString();
        extnow = HoldVals.Rows[0]["ExitNow"].ToString();
        return HoldVals;

    }

Answer 1

您需要保持对Output参数变量的引用，以便在适配器执行命令后，您可以使用parameter.Value访问返回给它的值。

//Create the parameter 
SqlParameter parameter = new SqlParameter("@mnpft", SqlDbType.VarChar);

//Set the parameter direction as output
parameter.Direction = ParameterDirection.Output;

sqlCommand.Parameters.Add(parameter);

SqlDataAdapter sqlAdapter = new SqlDataAdapter(sqlCommand);
sqlAdapter.Fill(dataSet);

//Fetch the output parameter after doing the Fill
string outputValue = Convert.ToString(parameter.Value);