将.CSV文件读入控制台（问题） [英] Reading .CSV File Into Console (Problem)

问题描述

所以，我有一个问题，尝试将csv文件读入控制台，我目前有下面的代码，但有一个错误，我不明白，并搜索网络，无法找到。基本上它没有显示文件的内容，而是在控制台上显示此错误。



System.Collections.Generic.List'1 [System.String]



请有人帮我解决这个问题。

So, i have a problem with trying to read a csv file into a console, i currently have the below code which works but with one error i do not understand and have searched the web for and cant find. Basically instead of it showing the contents of the file it shows this error on the console.

"System.Collections.Generic.List'1[System.String]"

Cant anybody please help me solve this please.

using System;
using System.Linq;
using System.Text;
using System.IO;
using System.Collections.Generic;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var reader = new StreamReader(File.OpenRead(@"D:\Book1.csv"));
            List<string> listA = new List<string>();
            while (!reader.EndOfStream)
            {
                var line = reader.ReadLine();
                var values = line.Split(',');

                listA.Add(values[0]);
                Console.WriteLine(listA);
            }
        }
    }
}

推荐答案

它正在做你告诉它的事情要做的事 - 打印 listA 的字符串表示。 :)



而是将 Console.WriteLine 调用移至while循环外部并将其更改为：

It's doing what you told it to do - print the string representation of listA. :)

Instead move the Console.WriteLine call to outside your while loop and change it to:

foreach (string s in listA) {
  Console.WriteLine (s);
}

/ ravi

没有一个Collection类实现ToString：这意味着使用默认的对象版本 - 只打印类的名称，而不是内容。

所以

None of the Collection classes implement ToString: which means the use the default object version - which just prints the name of the class, not the content.
So

Console.WriteLine(listA);

隐式ToString方法是否在List上调用，并打印类的名称：它是一个通用的字符串列表。



如果你想打印列表的内容，那么你需要循环播放内容并依次打印每个项目：

Does an implicit ToString method call on the List, and prints the name of the class: "it's a generic List of strings".

If you want to print the content of the list, then you need to loop though teh content and print each item in turn:

foreach(string s in listA)
   {
   Console.WriteLine(s);
   }

是一种方法。

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