用C#将数据写入CSV文件 [英] Writing data into CSV file in C#

问题描述

我正在尝试使用 C# 语言逐行写入 csv 文件.这是我的功能

I am trying to write into a csv file row by row using C# language. Here is my function

string first = reader[0].ToString();
string second=image.ToString();
string csv = string.Format("{0},{1}
", first, second);
File.WriteAllText(filePath, csv);

整个函数在一个循环中运行，每一行都应该写入csv文件.就我而言，下一行覆盖了现有行，最后，我在 csv 文件中获得了唯一一条记录，这是最后一条记录.如何写入 csv 文件中的所有行?

The whole function runs inside a loop, and every row should be written to the csv file. In my case, next row overwrites the existing row and in the end, I am getting an only single record in the csv file which is the last one. How can I write all the rows in the csv file?

推荐答案

UPDATE

在我幼稚的日子里，我建议手动执行此操作(这是一个简单问题的简单解决方案)，但是由于这变得越来越流行，我建议使用库 CsvHelper 执行所有安全检查等.

Back in my naïve days, I suggested doing this manually (it was a simple solution to a simple question), however due to this becoming more and more popular, I'd recommend using the library CsvHelper that does all the safety checks, etc.

CSV 比问题/答案所暗示的要复杂得多.

CSV is way more complicated than what the question/answer suggests.

原答案

因为你已经有了一个循环，考虑这样做:

As you already have a loop, consider doing it like this:

//before your loop
    var csv = new StringBuilder();

//in your loop
    var first = reader[0].ToString();
    var second = image.ToString();
    //Suggestion made by KyleMit
    var newLine = string.Format("{0},{1}", first, second);
    csv.AppendLine(newLine);  

//after your loop
    File.WriteAllText(filePath, csv.ToString());

或者类似的东西.我的理由是:您不需要为每个项目都写入文件，您只需打开流一次然后再写入.

Or something to this effect. My reasoning is: you won't be need to write to the file for every item, you will only be opening the stream once and then writing to it.

可以替换

File.WriteAllText(filePath, csv.ToString());

与

File.AppendAllText(filePath, csv.ToString());

如果您想将以前版本的 csv 保留在同一文件中

if you want to keep previous versions of csv in the same file

C# 6

如果您使用的是 c# 6.0，那么您可以执行以下操作

If you are using c# 6.0 then you can do the following

var newLine = $"{first},{second}"

编辑

这是一个链接到一个解释什么的问题Environment.NewLine 确实如此.

Here is a link to a question that explains what Environment.NewLine does.

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