Question

希望一切顺利。

我在这里遇到一个简单的问题。我正在尝试创建一个控制台应用程序，允许您搜索列表中的单词（通过一个或多个字符，即u =用户，用户组）。

我似乎无法克服这个错误：错误CS0305使用通用类型＆＃39;列表＆＃39;需要1个类型参数wordSearch c：\ Projects \ wordSearch \ wordSearch \ Program.cs 36 Active

请在下面找到我的代码.....欢迎任何帮助提前谢谢。

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

namespace wordSearch
{


public class MyList<T> { }
public class TestList<T> { }

class MyList
{
    public static void Main()
    {

        string searchKeyword = "o";

        List<string> items = new List<string>();
        items.Add("User");
        items.Add("User Groups");
        items.Add("User Activity Log");
        items.Add("Report Designer");
        items.Add("Report Activity Log");



        List<string> searchResults = items.FindAll(u => 
         u.Contains(searchKeyword));


            Console.WriteLine("Please type in the first letter of item you 
            are looking for:");
            Console.ReadLine();

        foreach (var result in System.Collections.Generic.List.Where(u => 
         u.IndexOf(mySearchString) == 0))
        {
            Console.WriteLine("User, User Groups, User Activity Log");
            Console.ReadKey();
        }
       foreach (var result in List.Where(r => r.IndexOf(mySearchString) == 
        0))
        {
            Console.WriteLine("Report Desinger, Report Activity Log");
            Console.ReadKey();
        }
    }
}

}

Answer 1

您的代码存在两个问题：

你必须保存用户的输入（“......用户正在寻找的第一个字母......”），例如在您已用作过滤器的mySearchString中。
您必须查询并扫描items 实例，而不是System.Collections.Generic.ListList 类型：

你可以这样说：

  ...

  Console.WriteLine("Please type in the first letter of item you are looking for:");

  //DONE: user input saved
  string mySearchString = Console.ReadLine();

  //DONE: we scan items, not List 
  foreach (var result in items.Where(u => u.IndexOf(mySearchString) == 0)) {
      Console.WriteLine("User, User Groups, User Activity Log");
      Console.ReadKey();
  }

  // DONE: we scan items not List
  foreach (var result in items.Where(r => r.IndexOf(mySearchString) == 0)) {
    Console.WriteLine("Report Desinger, Report Activity Log");
    Console.ReadKey();
  }

  ...

编辑：似乎实际的请求是在循环中查询列表，foreach而不是复制粘贴，如下所示：

public static void Main() {
  List<string> items = new List<string>() {
    "User",
    "User Groups",
    "User Activity Log",
    "Report Designer",
    "Report Activity Log",
  }

  while (true) {
    Console.WriteLine("Please type in the first letter of item you are looking for:");
    Console.WriteLine("Prease press enter (i.e. type an empty string) to quit"); 

    string mySearchString = Console.ReadLine();

    if (string.IsNullOrEmpty(mySearchString)) 
      break;

    foreach (var item in items.Where(r => r.IndexOf(mySearchString) == 0))
      Console.WriteLine(item);

    Console.WriteLine();
  }
}

搜索列表C＃

1 个答案: