相关疑难解决方法(0)

好的,我已成功完成以下工作

public IQueryable getTicketInformation(int ticketID)
{
    var ticketDetails = from tickets in _context.tickets
        join file in _context.file_objects on tickets.ticket_id equals file.source_id
        where tickets.ticket_id == ticketID
        select new { tickets.ticket_id, tickets.title, tickets.care_of_email, file.filename };

    return ticketDetails.AsQueryable();
}

我继续创建自己的类(myObject),其中包含基元ticket_id,title,care_of_email和filename.我在linq声明中返回的是哪些项目.

我修改了我的陈述

public IQueryable<myObject> getTicketInformation(int ticketID)
{
    var ticketDetails = from tickets in _context.tickets
        join file in _context.file_objects on tickets.ticket_id equals file.source_id
        where tickets.ticket_id == ticketID
        select new { tickets.ticket_id, tickets.title, tickets.care_of_email, file.filename };

    return ticketDetails.AsQueryable()<myObject>;
}

认为这会使泛型的类型安全,但我得到错误"无法将方法组'AsQueryable'转换为非委托类型'System.Linq.IQueryable'.你打算调用该方法吗？"

我甚至想做什么？

myObject类是否需要实现IEnumerable或IQueryable？

或者最好从linq结果集构造对象MyObject,然后从函数返回对象MyObject

public myObject getTicketInformation(int …

我有两个简单的列表:

public partial class Visitor
{
    public Visitor()
    {
        this.Visits = new HashSet<Visit>();
    }

    public int Id { get; set; }
    public int PermitId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string MiddleName { get; set; }
    public bool IsValid { get; set; }
    public System.DateTime RegistrationDate { get; set; }
    public byte[] Picture { get; set; }
    public virtual ICollection<Visit> Visits { get; set; }
}

public …