C# RDLC报告未加载数据

我已经开发了一个asp.net应用程序，它应该显示我正在通过调用web服务从数据库加载的RDLC报告。该web服务很好，但RDLC没有加载数据。它显示空白的RDLC，而不是显示数据库数据经度、纬度

代码：

网络服务：

public List<Coordinates> FetchCoordinates(String FetchParam) 
{
    List<Coordinates> Coords = new List<Coordinates>();
    Coordinates c;

    if(String.IsNullOrEmpty(FetchParam))
    {
        c = new Coordinates()
        {
             Error = "No Input Provided"
        };
        Coords.Add(c);
        return Coords;
    }

    String[] parts = FetchParam.Split(',');
    sqlCom.CommandText = "FetchCoordinates";
    sqlCom.CommandType = CommandType.StoredProcedure;

    String IMEI = parts[0].ToString();
    DateTime DateTimeFrom = Convert.ToDateTime(parts[1]); 
    DateTime DateTimeTo = Convert.ToDateTime(parts[2]);

    sqlCom.Parameters.Add("@IMEI", SqlDbType.VarChar).Value = IMEI;
    sqlCom.Parameters.Add("@DateTimeFrom", SqlDbType.DateTime).Value = DateTimeFrom.AddSeconds(-DateTimeFrom.Second);
    sqlCom.Parameters.Add("@DateTimeTo", SqlDbType.DateTime).Value = DateTimeTo.AddSeconds(-DateTimeTo.Second);
    SqlParameter sqlParam = new SqlParameter("@result", SqlDbType.Int);
    sqlCom.Parameters.Add(sqlParam);
    sqlCom.Parameters["@result"].Direction = ParameterDirection.Output;

    try
    {
        sqlCon.Open();
        using (SqlDataReader reader = sqlCom.ExecuteReader())
        {
             if (reader.HasRows)
             {
                  while (reader.Read())
                  {
                      c = new Coordinates()
                      {
                           Longitude = reader["Longitude"].ToString(),
                           Latitude = reader["Latitude"].ToString(),
                           // Error = "Times:"+"Original="+DateTimeFrom+"<br/>"+"Trimmed Time"+DateTimeFrom.AddSeconds(-DateTimeFrom.Second)
                      };
                            Coords.Add(c);

                  }
                  return Coords;
             }
             else
             {
                  c = new Coordinates()
                  {
                       Error = "No Data Found for Given Input. Could be Server Error or Try Changing IMEI or DateTime Format"
                  };
                  Coords.Add(c);
                  return Coords;
             }
        }
    }

    catch (Exception)
    {

        c = new Coordinates() 
        { 
             Error = "Something Went Wrong" 
        };
        Coords.Add(c);
        return Coords;

    }

    finally
    {
        sqlCon.Close();
    }
}

---

我也有同样的问题，我的报告中有一些行对象，被删除了，它显示了

添加这个。ReportViewer1.RefreshReport；添加数据源之后。确认数据源是否包含记录。错误：错误1事件“Microsoft.Reporting.WebForms.ReportViewer.ReportRefresh”只能出现在+=或-=数据源正在返回列表的左侧，是列表由包含31条记录的两列填写，但rdlc未显示，为什么？ReportViewer1.LocalReport.Referesh而不是RefreshReport；Hassansar不工作

public List<Coordinates> FetchCoordinates(String FetchParam) 
{
    List<Coordinates> Coords = new List<Coordinates>();
    Coordinates c;

    if(String.IsNullOrEmpty(FetchParam))
    {
        c = new Coordinates()
        {
             Error = "No Input Provided"
        };
        Coords.Add(c);
        return Coords;
    }

    String[] parts = FetchParam.Split(',');
    sqlCom.CommandText = "FetchCoordinates";
    sqlCom.CommandType = CommandType.StoredProcedure;

    String IMEI = parts[0].ToString();
    DateTime DateTimeFrom = Convert.ToDateTime(parts[1]); 
    DateTime DateTimeTo = Convert.ToDateTime(parts[2]);

    sqlCom.Parameters.Add("@IMEI", SqlDbType.VarChar).Value = IMEI;
    sqlCom.Parameters.Add("@DateTimeFrom", SqlDbType.DateTime).Value = DateTimeFrom.AddSeconds(-DateTimeFrom.Second);
    sqlCom.Parameters.Add("@DateTimeTo", SqlDbType.DateTime).Value = DateTimeTo.AddSeconds(-DateTimeTo.Second);
    SqlParameter sqlParam = new SqlParameter("@result", SqlDbType.Int);
    sqlCom.Parameters.Add(sqlParam);
    sqlCom.Parameters["@result"].Direction = ParameterDirection.Output;

    try
    {
        sqlCon.Open();
        using (SqlDataReader reader = sqlCom.ExecuteReader())
        {
             if (reader.HasRows)
             {
                  while (reader.Read())
                  {
                      c = new Coordinates()
                      {
                           Longitude = reader["Longitude"].ToString(),
                           Latitude = reader["Latitude"].ToString(),
                           // Error = "Times:"+"Original="+DateTimeFrom+"<br/>"+"Trimmed Time"+DateTimeFrom.AddSeconds(-DateTimeFrom.Second)
                      };
                            Coords.Add(c);

                  }
                  return Coords;
             }
             else
             {
                  c = new Coordinates()
                  {
                       Error = "No Data Found for Given Input. Could be Server Error or Try Changing IMEI or DateTime Format"
                  };
                  Coords.Add(c);
                  return Coords;
             }
        }
    }

    catch (Exception)
    {

        c = new Coordinates() 
        { 
             Error = "Something Went Wrong" 
        };
        Coords.Add(c);
        return Coords;

    }

    finally
    {
        sqlCon.Close();
    }
}