c#读写大文件（大于20g）

c#读写大文件（大于20g），是二进制大文件的读写，谢谢各位

The problem with your solution is that you recreate the streams in each iteration. Try this version:

const int MAX_BUFFER = 33554432; //32MB
byte[] buffer = new byte[MAX_BUFFER];
int bytesRead;
StringBuilder currentLine = new StringBuilder();

using (FileStream fs = File.Open(filePath, FileMode.Open, FileAccess.Read))
using (BufferedStream bs = new BufferedStream(fs))
{
    string line;
    bool stop = false;
    var memoryStream = new MemoryStream(buffer);
    var stream = new StreamReader(memoryStream);
    while ((bytesRead = bs.Read(buffer, 0, MAX_BUFFER)) != 0)
    {
        memoryStream.Seek(0, SeekOrigin.Begin);

        while (!stream.EndOfStream)
        {
            line = ReadLineWithAccumulation(stream, currentLine);

            if (line != null)
            {
                //process line
            }
        }
    }
}

private string ReadLineWithAccumulation(StreamReader stream, StringBuilder currentLine)
{
    while (stream.Read(buffer, 0, 1) > 0)
    {
        if (charBuffer [0].Equals('\n'))
        {
            string result = currentLine.ToString();
            currentLine.Clear();

            if (result.Last() == '\r') //remove if newlines are single character
            {
                result = result.Substring(0, result.Length - 1);
            }

            return result;
        }
        else
        {
            currentLine.Append(charBuffer [0]);
        }
    }

    return null;  //line not complete yet
}

private char[] charBuffer = new char[1];

循环读取，参考：

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

namespace IO目录管理
{
class Program
{
private string _StrSourcePath = @”E:\TestDir\Test\1.txt”; //源文件目录
private string _StrTagrgetPath = @”F:\TestDir\Test\1.txt”; //目标文件目录

    public void Test()
    {
        //路径合法性判断
        if(File.Exists(_StrSourcePath))
        {
            //构造读取文件流对象
            using (FileStream fsRead = new FileStream(_StrSourcePath, FileMode.Open)) //打开文件，不能创建新的
            {
                //构建写文件流对象
                using (FileStream fsWrite = new FileStream(_StrTagrgetPath,FileMode.Create)) //没有找到就创建
                {
                    //开辟临时缓存内存
                    byte[] byteArrayRead = new byte[1024 * 1024]; //  1字节*1024 = 1k 1k*1024 = 1M内存

                    //通过死缓存去读文本中的内容
                    while(true)
                    {
                        //readCount  这个是保存真正读取到的字节数
                        int readCount =  fsRead.Read(byteArrayRead, 0, byteArrayRead.Length);

                        //开始写入读取到缓存内存中的数据到目标文本文件中
                        fsWrite.Write(byteArrayRead, 0, readCount);


                        //既然是死循环 那么什么时候我们停止读取文本内容 我们知道文本最后一行的大小肯定是小于缓存内存大小的
                        if(readCount < byteArrayRead.Length)
                        {
                            break;  //结束循环
                        }
                    }
                }
            }
        }
        else
        {
            Console.WriteLine("源路径或者目标路径不存在。");
        }
    }


    static void Main(string[] args)
    {
        Program p = new Program();
        p.Test();

    }
}

如果写入呢，用int这种循环写入吗

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