使用LINQ:如何从类集合返回属性数组? [英] Using LINQ: How To Return Array Of Properties from a Class Collection?

问题描述

这是带有TheProperty的基本类:

class BasicClass {
  public BasicClass() {
    TheProperty = new Object();
    Stamped = DateTime.Now;
  }
  public object TheProperty { get; set; }
  public DateTime Stamped { get; private set; }
}

这是基本列表:

class BasicList {
  private List<BasicClass> list;
  public BasicList() {
    list = new List<BasicClass>();
  }
  public BasicClass this[object obj] {
    get { return list.SingleOrDefault(o => o.TheProperty == obj); }
  }
  public void Add(BasicClass item) {
    if (!Contains(item.TheProperty)) {
      list.Add(item);
    }
  }
  public bool Contains(object obj) {
    return list.Any(o => o.TheProperty == obj); // Picked this little gem up yesterday!
  }
  public int Count { get { return list.Count; } }
}

我想向BasicList添加一个类，该类将返回项目数组.

I'd like to add a class to BasicList that will return an array of items.

我可以使用传统的C#这样写:

I could write it like this, using traditional C#:

public object[] Properties() {
  var props = new List<Object>(list.Count);
  foreach (var item in list) {
    props.Add(item.TheProperty);
  }
  return props.ToArray();
}

...但是我怎么用LINQ或Lambda查询写出来呢?

推荐答案

return list.Select(p=>p.TheProperty).ToArray()

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