文件操作/文件夹操作

文件夹会创建在\bin\Debug\net6.0

namespace _23_文件操作
{internal class Program{static void Main(string[] args){-------------------文件操作File--------------//复制方法1FileInfo myFile = new FileInfo("E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile1.txt");if (!myFile.Exists)myFile.CopyTo("E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile2.txt");//复制方法2if (!myFile.Exists)File.Copy("E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile1.txt","E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile3.txt");//修改时间myFile.CreationTime = DateTime.Now;myFile.LastAccessTime = DateTime.Now;myFile.LastWriteTime = DateTime.Now;Console.WriteLine(myFile.Extension);Console.WriteLine(myFile.FullName);Console.WriteLine(myFile.Length);-----------------文件夹操作Directory--------------DirectoryInfo myDirectory = new DirectoryInfo(@"create");myDirectory.Create();Console.WriteLine(myDirectory.FullName);Directory.CreateDirectory("E:\\VScodes\\第四季-高级编程\\23-文件操作\\bin\\Debug\\net6.0\\create\\sondirectory");if (myDirectory.FullName != "E:\\VScodes\\第四季-高级编程\\23-文件操作\\bin\\Debug\\net6.0\\create")myDirectory.MoveTo("newcreate");Console.WriteLine(myDirectory.FullName);FileSystemInfo[] fileInfo = myDirectory.GetFileSystemInfos();foreach (var item in fileInfo){Console.WriteLine(item.FullName);}DirectoryInfo myFolder = new DirectoryInfo(@"c:\program files");}}
}

流操作

流是比喻成水流，一片海很难一次性运动，但一瓢一瓢舀还是能移动

文件的操作是消耗内存的，如果不用流，大文件会占很多内存，用流可以减少内存消耗

新建FileStream流，需要3个参数，具体可以查阅资料【C# 教程系列第 19 篇】FileMode，FileAccess 的参数释义_c# filemode_Allen Su的博客-CSDN博客

操作完，记得关闭流：顺序：先开后关，后开先关；先关闭独立需要依赖的文件，后关闭被依赖文件

Console.WriteLine("-----------------读取写入流--------------");FileStream readFileStream = new FileStream("D:\\Halcon安装包\\halcon-12.0-windows-64.exe",FileMode.Open,FileAccess.Read);//readFileStream.ReadByte();//一个字节一个字节的读,读完后返回-1//复制字节，注意模式，需要先建立一个文件，文件路径是不存在的FileStream writeFileStream = new FileStream("E:\\VScodes\\第四季-高级编程\\copyfile.exe", FileMode.Create, FileAccess.Write);//writeFileStream.WriteByte(0);int nextByte = -1;while((nextByte = readFileStream.ReadByte()) != -1){//把读到的写入新文件writeFileStream.WriteByte((byte)nextByte);}//先开的流后关，后开先关writeFileStream.Close();readFileStream.Close();

 修改读取数据：

不再用readbyte和writebyte，改为read，write

readFileStream.Read会放回读取的长度，读完之后返回0

FileStream readFileStream = new FileStream("D:\\Halcon安装包\\halcon-12.0-windows-64.exe", FileMode.Open, FileAccess.Read);FileStream writeFileStream = new FileStream("E:\\VScodes\\第四季-高级编程\\copyfile.exe", FileMode.Create, FileAccess.Write);DateTime befor1 = DateTime.Now;byte[] buffer = new byte[1024];int count = -1;while((count = readFileStream.Read(buffer,0,1024))!=0){writeFileStream.Write(buffer, 0, count);}DateTime after1 = DateTime.Now;TimeSpan ts1 = after1 - befor1;writeFileStream.Close();readFileStream.Close();Console.WriteLine(ts1.TotalMilliseconds);

一般读写流操作

注意创建时：，最后一个参数设置为覆盖模式（false默认），还是追加模式（true）

StreamWriter writer = new StreamWriter(destination, true);//追加的方式添加文本

string sourceFile = "E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile2.txt";string destination = "E:\\VScodes\\第四季-高级编程\\23-文件操作\\TextFile4.txt";StreamReader reader = new StreamReader(sourceFile);//StreamWriter writer = new StreamWriter(destination,false);//会覆盖StreamWriter writer = new StreamWriter(destination, true);//追加的方式添加文本//string line = null;//while ((line = reader.ReadLine()) != null)//    writer.WriteLine(line);string nextLine = reader.ReadLine();//读一行Console.WriteLine(nextLine);int nextchar = reader.Read();//读一个字符ascii码Console.WriteLine(nextchar);int nChars = 10;char[] charArray = new char[nChars];int nCharsRead = reader.Read(charArray, 0, nChars);foreach (char c in charArray){ Console.WriteLine(c); }string restOfStream = reader.ReadToEnd();//把剩下的读完Console.WriteLine(restOfStream);writer.Close();reader.Close();