Question

我尝试循环浏览列表并将内容放入viewbag中。我的问题是，当我在视图中抓取viewbag时，它只显示循环最后一次迭代的内容。关于发生了什么的任何想法？这是一个例子：

var output = new List<AirportsInACity>();

foreach (var airport in cities)
{
     var temp = new AirportsInACity();

     temp.airportName = airport.name
     temp.aircraftList = new List<AirportAircraftTypeList>();

     foreach (aircraft in airport.aircraftTypes)
     {
         aircraftTemp = new AirportAircraftTypeList();
         aircraftTemp.aircraftType = aircraft.AircraftType.AircraftTypeModel;
         aircraftTemp.seats = aircraft.Seats;
         aircraftTemp.attendants = aircraft.Attendants;

         temp.aircraftList.Add(aircraftTemp);

     }

     output.Add(temp);

     var outputStats = temp.AircraftList.GroupBy(p => p.aircraftType);

     foreach (var item in outputStats)
     {
         ViewBag.AirportName = temp.name;
         ViewBag.AirportAircraftType = item.Key;
         ViewBag.AircraftSeatsSum = item.Sum(p => p.seats);
     }
 }

 ViewBag.Output = output;
 return PartialView(output);

现在，让我说我有这个信息：

Airport Name: JFK Aircraft Type: Boeing777 Total Seats: 400

Airport Name: ATL Aircraft Type: Boeing777 Total Seats: 800

Airport Name: LAS Aircraft Type: Boeing727 TotalSeats: 150

问题在于，在我的Viewbag中，它只抓取最后一块信息（LAS机场），但控制台正在输出所有信息。问题是什么？

以下是视图的示例：

@foreach (var item in Viewbag.Output)
{
    <td>@(ViewBag.AirportName)</td>
    <td>@(ViewBag.AirportAircraftType)</td>
    <td>@(ViewBag.AircraftSeatsSum)</td>
}

Answer 1

在ViewBag.Output上，您有一个包含以下属性的AirportsInACity类型列表：airportName和aircraftList，其中包含AirportAircraftTypeList类型的列表。接下来，你有一个foreach到`outputStat＆＃39;该设置始终是 SAME ViewBag项目。

您必须创建一个新的viewmodel，其中放置outputStats

public class AircraftViewModel
{
    public string AirportName {get; set; }

    public string AirportAircraftType {get; set;}

    public int AircraftSeatsSum {get; set; }
}

[..]

var outputStats = temp.AircraftList.GroupBy(p => p.aircraftType);
List<AircraftViewModel> vm = new List<AircraftViewModel>();

     foreach (var item in outputStats)
     {
         var aircraft = new AircraftViewModel();
         aircraft.AirportName = temp.name;
         aircraft.AirportAircraftType = item.Key;
         aircraft.AircraftSeatsSum = item.Sum(p => p.seats);
         vm.Add(aircraft);
     }
 }

 ViewBag.Output = vm;

Answer 2

创建ExpandoObject并将其添加到“详细信息列表”。

示例：

控制器代码：

List<dynamic> Details = new List<dynamic>();

 foreach (var item in outputStats)
                {
                   dynamic detail;

                   detail = new ExpandoObject();
                   detail.AirportName  =temp.name;
                   detail.AirportAircraftType  = item.Key;
                   detail.AircraftSeatsSum =item.Sum(p => p.seats);

                  Details.Add(detail);
                }

ViewBag.Details = Details;

查看代码：

@foreach (dynamic detail in ViewBag.Details)
{
   <td>@(detail.AirportName)</td>
        <td>@(detail.AirportAircraftType)</td>
        <td>@(detail.AircraftSeatsSum)</td>
}

Viewbag只是从循环的最后一次迭代中获取信息

2 个答案: