c# - 无法将类型 'System.Linq.IQueryable' 隐式转换为 'System.Collections.Generic.IList'

Question

我有一个方法:

public DzieckoAndOpiekunCollection GetChildAndOpiekunByFirstnameLastname(string firstname, string lastname)
{
    DataTransfer.ChargeInSchoolEntities db = new DataTransfer.ChargeInSchoolEntities();
    DzieckoAndOpiekunCollection result = new DzieckoAndOpiekunCollection();
    if (firstname == null && lastname != null)
    {
        IList<DzieckoAndOpiekun> resultV = from p in db.Dziecko
                      where lastname == p.Nazwisko
                      **select** new DzieckoAndOpiekun(
                     p.Imie,
                     p.Nazwisko,
                     p.Opiekun.Imie,
                     p.Opiekun.Nazwisko)
                  ;
        result.AddRange(resultV);
    }
    return result;
}

选择的地方有错误:

Error 1 Cannot implicitly convert type 'System.Linq.IQueryable<WcfService1.DzieckoAndOpiekun>' to 'System.Collections.Generic.IList<WcfService1.DzieckoAndOpiekun>'. An explicit conversion exists (are you missing a cast?)

知道如何解决我的问题吗？

Answer 1

要将 IQuerable 或 IEnumerable 转换为列表，您可以执行以下操作之一:

IQueryable<object> q = ...;
List<object> l = q.ToList();

或:

IQueryable<object> q = ...;
List<object> l = new List<object>(q);