无法将数据 table 转换为 C# 中的列表

Question

我想将数据表数据显示到 html 中，以便将数据表转换为列表。但是获取错误不能隐式地将类型 'System.web.mvc.viewresult' 转换为 system.collection.genericlist

 public ViewResult Report_trans_consumption(DateTime? fromDate, DateTime? toDate)
        {
            ViewBag.fromDate = fromDate;
            ViewBag.toDate = toDate;
            List<Trans_energycons_ReportModel> model = null;
            using ("constr"))
            { 
                con.Open();
                SqlCommand cmd_get_transformer_consumption = new SqlCommand(@"SELECT 
    Date,units
    FROM [Total_Power]) desc", con);
                SqlDataAdapter da_get_trans_consumption = new SqlDataAdapter(cmd_get_transformer_consumption);
                DataTable dt = new DataTable();
                da_get_trans_consumption.Fill(dt);
                Trans_energycons_ReportModel m =new Trans_energycons_ReportModel();
                foreach (DataRow row in dt.Rows)
                {
                    string deviceDate = row["Date"].ToString();
                    string units = row["Units"].ToString();
                    m.DeviceDate =Convert.ToDateTime(deviceDate);
                    m.Units =Convert.ToDouble(units);
                    model.Add(m);//getting error here
                }
            }
            return View(model); 
        }
    }

型号

  public class Trans_energycons_ReportModel
    {
        public DateTime DeviceDate { get; set; }
        public double Units { get; set; }

    }

Answer 1

下一行无效

model = dt.AsEnumerable().ToList();

您必须根据数据 table 手动映射您的属性，例如

 foreach(DataRow row in dt.Rows)
 { 
     string deviceDate = row["DeviceDate"].ToString();
     string units = row["Units"].ToString();
     // convert your data and assign them in model and then use that model
 }

编辑：

您的 return 类型是 List<Trans_energycons_ReportModel>

所以你应该 return return model; 而不是 return View(model);

Answer 2

把List<Trans_energycons_ReportModel>改成ViewResult或ActionResult，像下面的代码：

public ViewResult Report_trans_consumption(DateTime? fromDate, DateTime? toDate)
{
 ....
}

无法将数据 table 转换为 C# 中的列表

unble to convert data table to list in c#

c#

generic-list