我如何在C＃中使用LINQ。选择时要保持类型？ [英] How can I maintain type when using LINQ .Select in C#?

问题描述

我试图返回一组不同的正在使用的子串第一个修整的结果，但是当我打电话，请选择将其转换为匿名类型。我似乎无法得到这个维持类型列表。我只需要返回在选择方法指定的字段

I'm trying to return a Distinct set of results that are first trimmed using Substring, but when I call "Select" it converts it to an anonymous type. I can't seem to get this to maintain the type "List". I only need to return the fields specified in the Select method.

public List<Facility> GetFacilities() {
    var facilities = new List<Facility>(); 
    facilities = _facilityRepository.GetAll().ToList();
    var facReturnList = 
        facilities.Where(x => x.Fac_Name = "Something")
                  .OrderBy(x => x.Fac_Name).ToList();

    var facReturnList2 = 
        facReturnList.Select(x => 
            new { ID = x.Fac_Name.Substring(0, 6), 
                  Fac_Name = x.Fac_Name.Substring(0, 3) })
            .Distinct().ToList();
    return facReturnList2;
}

我尝试添加列表<基金> 在新，但它说，这些属性（ ID 和 Fac_Name ）不会在设施中定义。

I tried adding List<Facility> after new, but it says those properties (ID and Fac_Name) aren't defined in Facility.

推荐答案

是否要初始化新的 ？基金与结果的实例

Do you want to initialize new Facility instances with your results?

var facReturnList2 = facReturnList.Select(x => new Facility { ID =   // ...
                                                   ^ concrete type initializer

响应修改：在选择运营商，你需要指定的类型的元素的要初始化，而不是他们的名单。您之前的代码似乎表明， Fac_Name 的是的在基金，定义，但它显然不会告发

Response to edit: Inside the Select operator, you need to specify the type of the elements that you want to initialize, not their list. Your prior code seems to indicate that Fac_Name is defined in Facility, but it obviously wouldn't be defined in List<Facility>.

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