使用c#在MS Sql Server中插入多行

我正试图使用c#将多行插入MS SQL服务器。我的代码将一个值插入到DB中，但随后抛出异常。我是c#新手，如果有任何帮助，我将不胜感激。

我使用的代码:

 private int InsertDataintoDB()
    {
        var dbConnection = new DBConnection();
        UserAppList userAppList = new UserAppList();
        userAppList.initList();
        var sqlString = "Insert into dbo.[OneSiteUserAccess](UserType, ApplicationCode) values(@appuserType,@appCode)";
        string connectionString = dbConnection.GetLASCentralWriterConnectionString();
        SqlConnection sqlConnection = new SqlConnection(connectionString);
        int rowsAffected = 0;
        List<USerType_AndAppCode> mylist = userAppList.myList;
        try
        {
            SqlCommand sqlCommand = new SqlCommand();
            sqlCommand.Connection = sqlConnection;
            sqlCommand.CommandType = CommandType.Text;
            sqlCommand.CommandText = sqlString;
            sqlConnection.OpenAsync();
            mytextArea.Append(sqlConnection.ConnectionTimeout.ToString());
            foreach (var user in mylist)
            {
                sqlCommand.Parameters.AddWithValue("@appuserType", user.UserType);
                sqlCommand.Parameters.AddWithValue("@appCode", user.AppCode);
                sqlCommand.ExecuteNonQuery();
                rowsAffected++;
            }
            sqlConnection.Close();
        }
        catch (SqlException e)
        {
            Console.WriteLine(e.StackTrace);
            mytextArea.Append(e.StackTrace);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.StackTrace); mytextArea.Append(e.StackTrace);
        }
        return rowsAffected;
    }
}

Error I am get

System.Data.SqlClient.SqlConnection。OnError (SqlException异常,布尔断开连接，动作1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action 1 wrapCloseInAction)在System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning (TdsParserStateObjectstatobj, Boolean callerHasConnectionLock, Boolean asyncClose) atSystem.Data.SqlClient.TdsParser。TryRun (RunBehavior RunBehavior,SqlCommand cmdHandler, SqlDataReader dataStreamBulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObjectstateObj Boolean&dataReady)System.Data.SqlClient.SqlCommand。FinishExecuteReader (SqlDataReader ds,RunBehavior RunBehavior, String resetOptionsString) atSystem.Data.SqlClient.SqlCommand.RunExecuteReaderTds (CommandBehaviorRunBehavior, RunBehavior，布尔值async, Int32 timeout, Task&asyncWrite, SqlDataReaderds)System.Data.SqlClient.SqlCommand.RunExecuteReader (CommandBehaviorRunBehavior, RunBehavior，布尔返回流，字符串TaskCompletionSource 1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSourcesendToPipe, Int32超时;布尔asyncWrite) atSystem.Data.SqlClient.SqlCommand.ExecuteNonQuery ()WebApplication_EmptyWebApp1.UserData.InsertDataintoDB ()c:'Users'csaini'Documents'Visual工作室2012 ' ' WebApplication_EmptyWebApp1 ' WebApplication_EmptyWebApp1项目' UserData.aspx.cs:行插入120行:1

引用

SqlCommand sqlCommand = new SqlCommand();
sqlCommand.Connection = sqlConnection;
sqlCommand.CommandType = CommandType.Text;
sqlCommand.CommandText = sqlString;
sqlConnection.Open();
mytextArea.Append(sqlConnection.ConnectionTimeout.ToString());
sqlCommand.Parameters.Add("@appuserType", SqlDbType.NVarChar);
sqlCommand.Parameters.Add("@appCode", SqlDbType.NVarChar);
foreach (var user in mylist)
{
    sqlCommand.Parameters["@appuserType"].Value = user.UserType;
    sqlCommand.Parameters["@appCode"].Value = user.AppCode;
    sqlCommand.ExecuteNonQuery();
    rowsAffected++;
}
sqlConnection.Close();