C#程序中创建、复制、移动、删除文件或文件夹的示例

创建文件或文件夹

您可通过编程方式在您的计算机上创建文件夹、子文件夹和子文件夹中的文件，并将数据写入文件。

public class createfileorfolder
{
  static void main()
  {
    string foldername = @"c:\top-level folder";

    string pathstring = system.io.path.combine(foldername, "subfolder");

    string pathstring2 = @"c:\top-level folder\subfolder2";

    system.io.directory.createdirectory(pathstring);

 
    string filename = system.io.path.getrandomfilename();

    pathstring = system.io.path.combine(pathstring, filename);

    console.writeline("path to my file: {0}\n", pathstring);

    if (!system.io.file.exists(pathstring))
    {
      using (system.io.filestream fs = system.io.file.create(pathstring))
      {
        for (byte i = 0; i < 100; i++)
        {
          fs.writebyte(i);
        }
      }
    }
    else
    {
      console.writeline("file \"{0}\" already exists.", filename);
      return;
    }

    try
    {
      byte[] readbuffer = system.io.file.readallbytes(pathstring);
      foreach (byte b in readbuffer)
      {
        console.write(b + " ");
      }
      console.writeline();
    }
    catch (system.io.ioexception e)
    {
      console.writeline(e.message);
    }

    system.console.writeline("press any key to exit.");
    system.console.readkey();
  }

}

输出：
path to my file: c:\top-level folder\subfolder\ttxvauxe.vv0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 8
3 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

如果该文件夹已存在，则 createdirectory 不执行任何操作，且不会引发异常。但是，file.create 用新的文件替换现有文件。该示例使用一个 if-else 语句阻止现有文件被替换。
通过在示例中做出以下更改，您可以根据具有某个名称的程序是否存在来指定不同的结果。如果该文件不存在，代码将创建一个文件。如果该文件存在，代码将把数据添加到该文件中。
指定一个非随机文件名。

// comment out the following line.
//string filename = system.io.path.getrandomfilename();

// replace that line with the following assignment.
string filename = "mynewfile.txt";

用以下代码中的 using 语句替换 if-else 语句。

using (system.io.filestream fs = new system.io.filestream(pathstring, filemode.append)) 
{
  for (byte i = 0; i < 100; i++)
  {
    fs.writebyte(i);
  }
}

运行该示例若干次以验证数据是否每次都添加到文件中。

复制、删除和移动文件和文件夹
以下示例说明如何使用 system.io 命名空间中的 system.io.file、system.io.directory、system.io.fileinfo 和 system.io.directoryinfo 类以同步方式复制、移动和删除文件和文件夹。 这些示例没有提供进度栏或其他任何用户界面。
。
示例
下面的示例演示如何复制文件和目录。

public class simplefilecopy
{
  static void main()
  {
    string filename = "test.txt";
    string sourcepath = @"c:\users\public\testfolder";
    string targetpath = @"c:\users\public\testfolder\subdir";

    // use path class to manipulate file and directory paths.
    string sourcefile = system.io.path.combine(sourcepath, filename);
    string destfile = system.io.path.combine(targetpath, filename);

    // to copy a folder's contents to a new location:
    // create a new target folder, if necessary.
    if (!system.io.directory.exists(targetpath))
    {
      system.io.directory.createdirectory(targetpath);
    }

    // to copy a file to another location and 
    // overwrite the destination file if it already exists.
    system.io.file.copy(sourcefile, destfile, true);

    // to copy all the files in one directory to another directory.
    // get the files in the source folder. (to recursively iterate through
    // all subfolders under the current directory, see
    // "how to: iterate through a directory tree.")
    // note: check for target path was performed previously
    //    in this code example.
    if (system.io.directory.exists(sourcepath))
    {
      string[] files = system.io.directory.getfiles(sourcepath);

      // copy the files and overwrite destination files if they already exist.
      foreach (string s in files)
      {
        // use static path methods to extract only the file name from the path.
        filename = system.io.path.getfilename(s);
        destfile = system.io.path.combine(targetpath, filename);
        system.io.file.copy(s, destfile, true);
      }
    }
    else
    {
      console.writeline("source path does not exist!");
    }

    // keep console window open in debug mode.
    console.writeline("press any key to exit.");
    console.readkey();
  }
}

下面的示例演示如何移动文件和目录。

public class simplefilemove
{
  static void main()
  {
    string sourcefile = @"c:\users\public\public\test.txt";
    string destinationfile = @"c:\users\public\private\test.txt";

    // to move a file or folder to a new location:
    system.io.file.move(sourcefile, destinationfile);

    // to move an entire directory. to programmatically modify or combine
    // path strings, use the system.io.path class.
    system.io.directory.move(@"c:\users\public\public\test\", @"c:\users\public\private");
  }
}

下面的示例演示如何删除文件和目录。

public class simplefiledelete
{
  static void main()
  {
    // delete a file by using file class static method...
    if(system.io.file.exists(@"c:\users\public\deletetest\test.txt"))
    {
      // use a try block to catch ioexceptions, to
      // handle the case of the file already being
      // opened by another process.
      try
      {
        system.io.file.delete(@"c:\users\public\deletetest\test.txt");
      }
      catch (system.io.ioexception e)
      {
        console.writeline(e.message);
        return;
      }
    }

    // ...or by using fileinfo instance method.
    system.io.fileinfo fi = new system.io.fileinfo(@"c:\users\public\deletetest\test2.txt");
    try
    {
      fi.delete();
    }
    catch (system.io.ioexception e)
    {
      console.writeline(e.message);
    }

    // delete a directory. must be writable or empty.
    try
    {
      system.io.directory.delete(@"c:\users\public\deletetest");
    }
    catch (system.io.ioexception e)
    {
      console.writeline(e.message);
    }
    // delete a directory and all subdirectories with directory static method...
    if(system.io.directory.exists(@"c:\users\public\deletetest"))
    {
      try
      {
        system.io.directory.delete(@"c:\users\public\deletetest", true);
      }

      catch (system.io.ioexception e)
      {
        console.writeline(e.message);
      }
    }

    // ...or with directoryinfo instance method.
    system.io.directoryinfo di = new system.io.directoryinfo(@"c:\users\public\public");
    // delete this dir and all subdirs.
    try
    {
      di.delete(true);
    }
    catch (system.io.ioexception e)
    {
      console.writeline(e.message);
    }

  }
}