无法隐式转换类型'System.Collections.Generic.List＆LT; AnonymousType＃1＆GT;'为“System.Collections.Generic.IEnumerable [英] Cannot implicitly convert type 'System.Collections.Generic.List<AnonymousType#1>' to 'System.Collections.Generic.IEnumerable

问题描述

现在，我尝试了右连接弹出一个例外。

这是我的控制器

 公开的IEnumerable＆LT;申请人GT; GetApplicant（）
    {
        IEnumerable的＆LT;申请人GT; applicantdata = Cache.Get（申请人）为IEnumerable＆LT;申请人取代;
        IEnumerable的＆LT;＆档案GT; profiledata = Cache.Get（配置文件）为IEnumerable＆LT;简介取代;
        如果（applicantdata == NULL）
        {            在context.Profiles变种applicantList =（从
                                 加入context.APPLICANTs应用
                                 在a.PROFILE_ID等于app.Profile_id成加盟
                                 从joined.DefaultIfEmptyĴ（）
                                 新选择
                                            {
                                               申请人= j的，
                                               外形= A，
                                            }）采取（1000）.AsEnumerable（）;                   applicantdata = applicantList.AsEnumerable（）了ToList（）。
            如果（applicantdata.Any（））
            {
                Cache.Set（申请人，applicantdata，30）;
            }
        }
        返回applicantdata;    }
 

这是错误

  applicantdata = applicantList.AsEnumerable（）了ToList（）。
 

  

无法隐式转换类型'System.Collections.Generic.List＆LT; AnonymousType＃1＆GT;'至
  System.Collections.Generic.IEnumerable＆LT; Applicant.Models.APPLICANT＆GT;'。明确
  转换存在（是否缺少强制转换？）

解决方案

applicantdata 是的IEnumerable＆LT;申请人GT; ，在你的SELECT语句您选择href=\"http://msdn.microsoft.com/en-us/library/vstudio/bb397696.aspx\" rel=\"nofollow\">匿名类型的对象使用<$ 新关键字，这就是为什么你不能把它转换为的IEnumerable＆LT;申请人GT; 。

您必须创建您的属性temporay类SELECT语句，并返回该类的的IEnumerable 。

我爱：

 公共类MyClass的
{
  公共申请人申请获取{;设置;}
  公开信息porfile {获取;设置;}
}
 

然后修改函数返回的IEnumerable＆LT; MyClass的＆GT; 像

 公开的IEnumerable＆LT; MyClass的＆GT; GetApplicant（）
{
    IEnumerable的＆LT; MyClass的＆GT; applicantdata = Cache.Get（申请人）为IEnumerable＆LT; MyClass的取代;
    IEnumerable的＆LT;＆档案GT; profiledata = Cache.Get（配置文件）为IEnumerable＆LT;简介取代;    IEnumerable的＆LT; MyClass的＆GT; applicantList;
    如果（applicantdata == NULL）
    {        applicantList =（来自于context.Profiles
                             加入context.APPLICANTs应用
                             在a.PROFILE_ID等于app.Profile_id成加盟
                             从joined.DefaultIfEmptyĴ（）
                             选择新MyClass的//改变这里
                                        {
                                           申请人= j的，
                                           外形= A，
                                        }）以（1000）;               applicantdata = applicantList.AsEnumerable（）;        如果（applicantdata = NULL＆放大器;！＆安培; applicantdata.Any（））
        {
            Cache.Set（申请人，applicantdata，30）;
        }
    }
    返回applicantdata;}
 

您不能投射到申请人，因为这似乎是通过实体框架生成的类。

Now that im trying the Right Join An Exception Popped up.

This is my Controller

   public IEnumerable<APPLICANT> GetApplicant()
    {
        IEnumerable<APPLICANT> applicantdata = Cache.Get("applicants") as IEnumerable<APPLICANT>;
        IEnumerable<Profile> profiledata = Cache.Get("profiles") as IEnumerable<Profile>;


        if (applicantdata == null)
        {

            var applicantList = (from a in context.Profiles 
                                 join app in context.APPLICANTs
                                 on a.PROFILE_ID equals app.Profile_id into joined
                                 from j in joined.DefaultIfEmpty()
                                 select new
                                            {
                                               APPLICANT = j, 
                                               Profile = a,
                                            }).Take(1000).AsEnumerable();

                   applicantdata = applicantList.AsEnumerable().ToList();


            if (applicantdata.Any())
            {
                Cache.Set("applicants", applicantdata, 30);
            }
        }
        return applicantdata;

    }

This is the error on

 applicantdata = applicantList.AsEnumerable().ToList();

Cannot implicitly convert type 'System.Collections.Generic.List<AnonymousType#1>' to 'System.Collections.Generic.IEnumerable<Applicant.Models.APPLICANT>'. An explicit conversion exists (are you missing a cast?)

解决方案

applicantdata is IEnumerable<APPLICANT>, in your select statement you are selecting anonymous type object using new keyword, that is why you can't convert it to IEnumerable<APPLICANT>.

You have to create a temporay class with your properties as in select statement and return IEnumerable of that class.

Like:

public class MyClass
{
  public APPLICANT applicant {get;set;}
  public Profile porfile {get;set;}
}

Then modify your function to return IEnumerable<MyClass> like

public IEnumerable<MyClass> GetApplicant()
{
    IEnumerable<MyClass> applicantdata = Cache.Get("applicants") as IEnumerable<MyClass>;
    IEnumerable<Profile> profiledata = Cache.Get("profiles") as IEnumerable<Profile>;

    IEnumerable<MyClass> applicantList;
    if (applicantdata == null)
    {

        applicantList = (from a in context.Profiles 
                             join app in context.APPLICANTs
                             on a.PROFILE_ID equals app.Profile_id into joined
                             from j in joined.DefaultIfEmpty()
                             select new MyClass //Change here
                                        {
                                           APPLICANT = j, 
                                           Profile = a,
                                        }).Take(1000);

               applicantdata = applicantList.AsEnumerable();



        if (applicantdata != null && applicantdata.Any())
        {
            Cache.Set("applicants", applicantdata, 30);
        }
    }
    return applicantdata;

}

You can't project to APPLICANT, since that appears to be a class generated through entity framework.

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