如何从LINQ查询创建DropDownList(How to create a DropDownList from a LINQ query)

我正在尝试使用LINQ查询的结果在MVC应用程序中创建下拉列表。我正在使用这个答案作为参考。但是，当我尝试为我的情况实现时，我得到错误： 'System.String' does not contain a property with the name 'SAMPLING_EVENT'

我的代码如下：

调节器

public class HomeController : Controller { // // GET: /Home/ public ActionResult Index() { ViewBag.Title = "Sample Tracker Tool"; DateTime nineMonthsAgo = DateTime.Now.AddDays(-270); var context = new EDMS_Entities(); var resultSet = (from samplingEvents in context.EDMS_SAMPLES where samplingEvents.RECORD_CREATED_DATE >= nineMonthsAgo orderby samplingEvents.SAMPLING_EVENT select samplingEvents.SAMPLE_ID) .Distinct(); var viewModel = new SamplingEventsVM(); viewModel.SamplingEvents = new SelectList(resultSet, "SAMPLING_EVENT", "SAMPLING_EVENT"); return View(viewModel); } }

ViewModel类

public class SamplingEventsVM { public int SelectedSamplingEvent { get; set; } public SelectList SamplingEvents { get; set; } }

视图

@model SamplingEventsVM <h2>@ViewBag.Title</h2> <span> @Html.DropDownListFor(model => model.SelectedSamplingEvent, Model.SamplingEvents, "Sampling Event") </span>

我究竟做错了什么？

I'm trying to use the results of a LINQ query to create a dropdownlist in an MVC app. I'm using this answer as a reference. However, when I try to implement for my case I get the error: 'System.String' does not contain a property with the name 'SAMPLING_EVENT'

My code is as follows:

Controller

ViewModel class

public class SamplingEventsVM { public int SelectedSamplingEvent { get; set; } public SelectList SamplingEvents { get; set; } }

View

@model SamplingEventsVM <h2>@ViewBag.Title</h2> <span> @Html.DropDownListFor(model => model.SelectedSamplingEvent, Model.SamplingEvents, "Sampling Event") </span>

What am I doing wrong?

最满意答案

您正在选择此select samplingEvents.SAMPLE_ID

所以你得到一个int列表，取决于你的ID类型

然后，您尝试使用属性值"SAMPLING_EVENT"创建一个选择列表

在您填充resultSet的int对象上不存在。

而是这样做：

var resultSet = (from samplingEvents in context.EDMS_SAMPLES where samplingEvents.RECORD_CREATED_DATE >= nineMonthsAgo orderby samplingEvents.SAMPLING_EVENT select samplingEvents) .Distinct();

You are selecting this select samplingEvents.SAMPLE_ID

So you get a List of int maybe, depends on your ID type

Then you try to make a select list with the property value "SAMPLING_EVENT"

Which doesn't exist on the int object you filled resultSet with.

Instead do this:

var resultSet = (from samplingEvents in context.EDMS_SAMPLES where samplingEvents.RECORD_CREATED_DATE >= nineMonthsAgo orderby samplingEvents.SAMPLING_EVENT select samplingEvents) .Distinct();

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