C#利用LINQ实现一个文件拆分成多个文件的示例详解

public static string ReadFile(string filePath)
{
    using (StreamReader reader = new StreamReader(filePath))
    {
        return reader.ReadToEnd();
    }
}

public static void SplitFile(string sourceFilePath, int linesPerFile)
{
    string content = ReadFile(sourceFilePath);
    string[] lines = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);

    var fileGroups = lines
        .Select((line, index) => new { Line = line, Index = index })
        .GroupBy(x => x.Index / linesPerFile)
        .Select(group => group.Select(x => x.Line).ToList());

    int fileIndex = 0;
    foreach (var group in fileGroups)
    {
        string newFileName = Path.Combine(Path.GetDirectoryName(sourceFilePath), $"SplitFile_{fileIndex}.txt");
        File.WriteAllLines(newFileName, group);
        fileIndex++;
    }
}

static void Main(string[] args)
{
    string sourceFilePath = @"C:\example\largeFile.txt";
    int linesPerFile = 1000;
    SplitFile(sourceFilePath, linesPerFile);

    Console.WriteLine("文件拆分完成！");
    Console.ReadKey();
}

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

class Program
{
    static void Main(string[] args)
    {
        // 设置源文件路径和目标文件夹路径
        string sourceFilePath = @"C:\example\largeFile.txt";
        string targetDirectoryPath = @"C:\example\SplitFiles";

        // 创建目标文件夹
        Directory.CreateDirectory(targetDirectoryPath);

        // 设置每个拆分文件的行数
        int linesPerFile = 1000;

        // 拆分文件
        SplitFile(sourceFilePath, targetDirectoryPath, linesPerFile);

        // 输出目标文件夹中的所有文件
        string[] files = Directory.GetFiles(targetDirectoryPath);
        foreach (string file in files)
        {
            Console.WriteLine(file);
        }

        Console.WriteLine("文件拆分完成！");
        Console.ReadKey();
    }

    static void SplitFile(string sourceFilePath, string targetDirectoryPath, int linesPerFile)
    {
        // 读取源文件内容
        string content = File.ReadAllText(sourceFilePath);
        string[] lines = content.Split(new string[] { Environment.NewLine }, StringSplitOptions.None);

        // 使用LINQ将文件内容分组
        var fileGroups = lines
            .Select((line, index) => new { Line = line, Index = index })
            .GroupBy(x => x.Index / linesPerFile)
            .Select(group => group.Select(x => x.Line).ToList());

        int fileIndex = 0;
        foreach (var group in fileGroups)
        {
            // 构建新的文件名
            string newFileName = Path.Combine(targetDirectoryPath, $"SplitFile_{fileIndex}.txt");

            // 写入拆分后的文件内容
            File.WriteAllLines(newFileName, group);

            fileIndex++;
        }
    }
}