using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Text;
using static System.Console;
//使用流处理文件
//FileStream
//读取器和写入器
//StreamReader StreamWriter
//读写二进制文件
//BinaryReader BinaryWriter
//压缩流
//使用DeflateStream和GZipStream来压缩和解压缩流
//它们使用同样的压缩算法，GZipStream在后台使用DeflateStream，增加了校验
//ZipArchive类可以创建和读取ZIP文件 //添加引用System.IO.Compression.dll, System.IO.Compression.FileSystem.dll
//Windows资源管理器可以直接打开ZipArchive，但不能打开GZipStream压缩的文件
//观察文件的更改
//FileSystemWatcher
namespace ConsoleApp
{
class Program
{
static void Main(string[] args)
{
//文件流
string fileName = "D:\\1.txt";
//using语句会自动调用(即使发生错误)该变量的Dispose()释放资源
using (var stream = new FileStream(fileName, FileMode.Open,
FileAccess.Read, FileShare.Read))
//FileStream stream1 = File.OpenRead(fileName);
{
//ShowStreamInfo(stream);
//GetEncoding(stream);
}
ReadFileUsingFileStream(fileName);
//WriteTextFile();
//压缩文件
CompressFile(fileName, "D:\\1.z");
//解压缩
DecompressFile("D:\\1.z");
//压缩文件
CreateZipFile("D:\\1", "D:\\1.zip");
//观察文件的更改
string path = "d:\\1";
string filter = "*.txt";//目录下所有txt文件
var watcher = new FileSystemWatcher(path, filter) { IncludeSubdirectories = true };
watcher.Created += OnFileChanged;
watcher.Changed += OnFileChanged;
watcher.Deleted += OnFileChanged;
watcher.Renamed += OnFileRenamed;
watcher.EnableRaisingEvents = true;
WriteLine("watching file changes...");
ReadKey();
}
private static Encoding GetEncoding(Stream stream)
{
if (!stream.CanSeek)
throw new ArgumentException("require a stream that can seek");
Encoding encoding = Encoding.ASCII;
byte[] bom = new byte[5];
int nRead = stream.Read(bom, offset: 0, count: 5);
if (bom[0] == 0xff && bom[1] == 0xfe && bom[2] == 0 && bom[3] == 0)
{
WriteLine("UTF-32");
stream.Seek(4, SeekOrigin.Begin);
return Encoding.UTF32;
}
else if(bom[0] == 0xff && bom[1] == 0xfe)
{
WriteLine("UFT-16, little endian");
stream.Seek(2, SeekOrigin.Begin);
return Encoding.Unicode;
}
else if (bom[0] == 0xfe && bom[1] == 0xff)
{
WriteLine("UTF-16, big endian");
stream.Seek(2, SeekOrigin.Begin);
return Encoding.BigEndianUnicode;
}
//UTF-8是Unicode的实现方式之一。(可变长度字符编码)
else if (bom[0] == 0xef && bom[1] == 0xbb && bom[2] == 0xbf)
{
WriteLine("UTF-8");
stream.Seek(3, SeekOrigin.Begin);
return Encoding.UTF8;
}
stream.Seek(0, SeekOrigin.Begin);
return encoding;
}
public static void ReadFileUsingFileStream(string fileName)
{
const int bufferSize = 1024;
using (var stream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read))
{
ShowStreamInfo(stream);
Encoding encoding = GetEncoding(stream);
byte[] buffer = new byte[bufferSize];
bool completed = false;
do
{
int nRead = stream.Read(buffer, 0, bufferSize);
if (nRead == 0)
completed = true;
if (nRead < bufferSize)
{
Array.Clear(buffer, nRead, bufferSize - nRead);
}
string s = encoding.GetString(buffer, 0, nRead);
WriteLine($"read {nRead} bytes");
WriteLine(s);
} while (!completed);
}
}
public static void ShowStreamInfo(FileStream stream)
{
WriteLine(stream.CanRead);
WriteLine(stream.CanWrite);
WriteLine(stream.CanSeek);
WriteLine(stream.CanTimeout);
WriteLine(stream.Position);
WriteLine(stream.Length);
if (stream.CanTimeout)
{
WriteLine(stream.ReadTimeout);
WriteLine(stream.WriteTimeout);
stream.ReadTimeout = 1000;//指定超时时间
stream.WriteTimeout = 1000;
}
}
public static void WriteTextFile()
{
string tempTextFileName = Path.ChangeExtension(Path.GetTempFileName(), "txt");
using (FileStream stream = File.OpenWrite(tempTextFileName))
{
////UTF-8
//stream.WriteByte(0xef);
//stream.WriteByte(0xbb);
//stream.WriteByte(0xbf);
//或
byte[] preamble = Encoding.UTF8.GetPreamble();
stream.Write(preamble, 0, preamble.Length);
string hello = "Hello, World!";
byte[] buffer = Encoding.UTF8.GetBytes(hello);
stream.Write(buffer, 0, buffer.Length);
WriteLine($"file{stream.Name} written");
}
}
public static void CompressFile(string fileName, string compressedFileName)
{
using (FileStream inputStream = File.OpenRead(fileName))
{
FileStream outputStream = File.OpenWrite(compressedFileName);
using (var compressStream =
new DeflateStream(outputStream, CompressionMode.Compress))
{
inputStream.CopyTo(compressStream);
}
}
}
public static void DecompressFile(string compressedFileName)
{
FileStream inputStream = File.OpenRead(compressedFileName);
using (MemoryStream outputStream = new MemoryStream())
using (var compressStream = new DeflateStream(inputStream,
CompressionMode.Decompress))
{
compressStream.CopyTo(outputStream);
outputStream.Seek(0, SeekOrigin.Begin);
using (var reader = new StreamReader(outputStream, Encoding.UTF8,
detectEncodingFromByteOrderMarks: true, bufferSize: 4096, leaveOpen: true))
{
string result = reader.ReadToEnd();
WriteLine(result);
}
}
}
public static void CreateZipFile(string directory, string zipFile)
{
FileStream zipStream = File.OpenWrite(zipFile);
using (var archive = new ZipArchive(zipStream, ZipArchiveMode.Create))
{
if (File.Exists(directory))
{
ZipArchiveEntry entry = archive.CreateEntry(Path.GetFileName(directory));
using (FileStream inputStream = File.OpenRead(directory))
using (Stream outputStream = entry.Open())
{
inputStream.CopyTo(outputStream);
}
}
else
{
//此方法不能压缩文件夹
IEnumerable<string> files = Directory.EnumerateFiles(directory, "*",
SearchOption.TopDirectoryOnly);
foreach (var file in files)
{
ZipArchiveEntry entry = archive.CreateEntry(Path.GetFileName(file));
using (FileStream inputStream = File.OpenRead(file))
using (Stream outputStream = entry.Open())
{
inputStream.CopyTo(outputStream);
}
}
}
}
}
private static void OnFileChanged(object sender, FileSystemEventArgs e)
{
WriteLine($"file {e.Name} {e.ChangeType}");
}
private static void OnFileRenamed(object sender, RenamedEventArgs e)
{
WriteLine($"file {e.OldName} {e.ChangeType} to {e.Name}");
}
}
}
