如何将治疗功能添加到我自己的链表中

Question

My question is to add treat with foreach my own linked list. I created my linked list by seeing example here

And I want to add LINQ to my linked list. Where i can see it? Or how i can implement it?

Answer 1

You just need to implement IEnumerabe<object> inside your LinkedList class:

public class LinkedList : IEnumerable<object>
{
        // your code
        // ....

        public IEnumerator<object> GetEnumerator()
        {
            var current = this.head;

            while (current != null)
            {
                yield return current.data;
                current = current.next;
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.GetEnumerator();
        }
}

Then, Linq will work:

var result = myLinkedList.Where(data => /* some condition */)
                         .Select(data => data.ToString();

As far as IEnumerable implementation is lazy evaluted ( yield return ) you would want to throw exception when list was modified while itering (to prevent bugs or sth):

public class LinkedList : IEnumerable<object>
{
     long version = 0;

     public void Add(object data) //it is required for all
                                  methods that modyfies collection
     {
         // yout code
         this.vesion += 1;
     }

     public IEnumerator<object> GetEnumerator()
     {
         var current = this.head;
         var v = this.version;

         while (current != null)
         {            
              if (this.version != v) 
                  throw new InvalidOperationException("Collection was modified");

              yield return current.data;
              current = current.next;
         } 
    }
}

Answer 2

您的链表需要实现IEnumerable<T> 。

Answer 3

You can implement a AsEnumerable() to use linq

public IEnumerable<T> AsEnumerable<T>()
{
    var current = root;
    while (current != null)
    {
        yield return current;
        current = current.NextNode;
    }
}