小编nev*_*hil的帖子

我希望能够使用Linq的'.where'语句和我的类'Books'(一个'Book'列表)来实现接口IEnumerable.

//THE PROBLEM IS HERE.
IEnumerable list3 = bookList.Where(n => n.author.Length >= 14);

我收到以下错误:

错误1'Assignment2CuttingPhilip.Books'不包含'Where'的定义,也没有扩展方法'Where'可以找到接受'Assignment2CuttingPhilip.Books'类型的第一个参数(你是否缺少using指令或汇编引用？) C:\ Users\Alex\Dropbox\cos570 CSharp\Assignment2CuttingPhilip\Assignment2CuttingPhilip\Assignement2PhilipCutting.cs 132 33 Assignment2CuttingPhilip

我的守则如下:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


namespace Assignment2CuttingPhilip
{
    public class Book 
    {
        public string title;
        public string author;

        public Book(string title, string author) {
            this.title = title;
            this.author = author;
        }

        public override string  ToString()
        {  return "Title:\'" + title + "\', Author:" + author;  }

    }

    public class Books : …