1、复制

// Simple synchronous file copy operations with no user interface.
// To run this sample, first create the following directories and files:
// C:\Users\Public\TestFolder
// C:\Users\Public\TestFolder\test.txt
// C:\Users\Public\TestFolder\SubDir\test.txt
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();
}
}

2、移动

// Simple synchronous file move operations with no user interface.
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");
}
}

3、删除

// Simple synchronous file deletion operations with no user interface.
// To run this sample, create the following files on your drive:
// C:\Users\Public\DeleteTest\test1.txt
// C:\Users\Public\DeleteTest\test2.txt
// C:\Users\Public\DeleteTest\SubDir\test2.txt

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);
}

}
}

总结自:​​如何复制、删除和移动文件和文件夹 - C# 编程指南 | Microsoft Docs​