小编BTE*_*BTE的帖子

我有以下两个问题

List<User> allUsers= dbContext.Users.ToList();
List<User> topTenUsers = dbContext.Users.Take(10).ToList();

它们是实例类的属性,它们都加载数据,如下面的代码:

using (var dbContext = new fooDataObjects.DataContext()) { 
    //...they are loaded here
}

问题是,当我尝试从allUsersi 访问结果集合时,会得到一个异常,上面写着"无法访问已处置的对象".但是我可以从中访问结果集合topTenUsers.

Take()强制LINQ枚举我可以从第二个集合中获得结果的结果元素吗？

实例设置为null后,实例委托方法如何仍可访问？下面的代码中的操作委托指向实例方法,但在将实例设置为null后,该方法仍然可用.

public class Work { public string Name{get;set;} } 

public class Worker
{
    public void Do(Work work)
    {
        Console.WriteLine("'{0}' is done.", work.Name);
    }
}

public class BatchWorker
{
    private List<Work> _works;
    public readonly Action<Work> Worker;
    public BatchWorker(Action<Work> worker)
    {
        _works = new List<Work>();
        Worker = worker;
    }
    public void AddWork(Work work)
    {
        this._works.Add(work);
    }
    public void DoWorks()
    {
        this._works.ForEach(this.Worker);
    }
}

public class Program{
    public static void Main(){
        var worker = new Worker();
        var batchWorker = new BatchWorker(worker.Do);
        batchWorker.AddWork(new Work …