FileVersionCopyFile.cs - Testing CopyTo() Method

C# Tutorials - Herong's Tutorial Examples

∟FileVersionCopyFile.cs - Testing CopyTo() Method

This section provides a tutorial example on how to use the FileInfo class to copy an existing file to a new file in the file system with the CopyTo() method.

In the previous section, we learned how to create a FileInfo object to represent a specific file in the file system.

Now let's write a more useful program to copy files using the FileInfo class:

// FileInfoCopyFile.cs
// Copyright (c) 2016 HerongYang.com. All Rights Reserved.

using System;
using System.IO;
public class FileInfoCopyFile {
   public static void Main(String[] args) {

      // Getting from command line arguments
      if (args.Length < 2) {
         Console.WriteLine("Usage: FileInfoCopyFile fromFile toFile");
         return;
      }
      string fromFile = args[0];
      string toFile = args[1];

      // Copy the file using CopyTo() method
      FileInfo fromFileObj = new FileInfo(fromFile);
      fromFileObj.CopyTo(toFile);
   }
}

Compile it with .NET SDK 4.6.1 and test it:

C:\herong>\windows\Microsoft.NET\Framework\v4.0.30319\csc
   FileInfoCopyFile.cs

C:\herong>FileInfoCopyFile \windows\System32\java.exe
   myjava.exe

C:\herong>myjava.exe -version
java version "1.6.0_30"
Java(TM) SE Runtime Environment (build 1.6.0_30-b12)
Java HotSpot(TM) Client VM (build 20.5-b03, mixed mode, sharing)

What happened in the test above:

Program FileInfoCopyFile first created a FileInfo object to represent the specified file: \windows\System32\java.exe.
Then the CopyTo() method on the object was used to copy file to the current directory as a new file named as myjava.exe.
The last step was to test the new file, myjava.exe, to make sure the copy process did not damage the file.