How to find and remove duplicate files in directory using C# code?

In today’s world It is common to have multiple similar images/videos in your computer and it takes lots of your disk space without your knowledge. I am inspired to write this article because I am getting lots of similar images, videos and documents in WhatsApp daily and it is very difficult for me to find duplicate files from directory. In this article, I’ll share C# code to find duplicate files from directory and also remove them.

Let’s look on below folder which contains multiple duplicate images. I want to find all duplicate images from this folder and delete them.

See below code to find and delete duplicate file from this folder.

Output -

As you can see duplicate files are deleted from your directory.

This programme can be used to delete any duplicate files like images, videos, documents etc.

I hope this code snippet helps you to find and remove duplicate files in your directory and make your life easy. Please leave your feedback in comments below.

See also –

Working with Directory class in C#

FileStream in .Net (C#)

Working with Performance Counters in C# .Net

Working with Directory Class in .Net (C#)

Directory class is static class provides static methods to do normal directory related operations such as Copy, Paste, Move, Rename, Delete etc. It is available in System.IO namespace.  Below code demonstrates some basic majorly used methods of directory class.

//Creates temp directory if not exist

if (!Directory.Exists(@"d:\temp"))

    Directory.CreateDirectory(@"d:\temp");

//set/get current directory

Directory.SetCurrentDirectory(@"d:\temp");

Console.WriteLine(Directory.GetCurrentDirectory());

//gets root of directory

Console.WriteLine(Directory.GetDirectoryRoot(@"d:\temp"));

//gets creation and last modified time of directory

Console.WriteLine(Directory.GetCreationTime(@"d:\temp"));

Console.WriteLine(Directory.GetLastWriteTime(@"d:\temp"));

           

//enumerates all files available in temp directory          

foreach (string file in Directory.EnumerateFiles(@"d:\temp"))

    Console.WriteLine(file);

//enumerates all directories available in temp directory

foreach (string directory in Directory.EnumerateDirectories(@"d:\temp"))

    Console.WriteLine(directory);

//enumerates all logical drives

foreach (string drive in Directory.GetLogicalDrives())

    Console.WriteLine(drive);

//deletes an empty directory. if not empty throws an exception

Directory.Delete(@"d:\temp");

Enumerate files and folders using DirectoryInfo

DirectoryInfo class provides some basic features to create, copy, move, rename and delete operations. It also provides some basic information like directory name, full path, attribute, root name etc. Let’s have a look on below code which loop through all the files and directories in specific directory.

DirectoryInfo di = new DirectoryInfo(@"d:\temp");

Console.WriteLine(di.FullName);

//gets all files in temp directory

foreach (FileInfo file in di.GetFiles())

    Console.WriteLine(file.Name);

//gets all directories in temp directory

foreach (DirectoryInfo dir in di.GetDirectories())

    Console.WriteLine(dir.Name);

How to get Special Folders?

Special folders are defined under Environment.SpecialFolder enum. This enum is available in System.Environment class. Let’s see how to get path for special folders like MyDocuments, MyPictures, Desktop, ProgramFiles, System, Windows etc.

Console.WriteLine("My Documents - {0}", Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));

Console.WriteLine("My Videos - {0}", Environment.GetFolderPath(Environment.SpecialFolder.MyVideos));

Console.WriteLine("Windows - {0}", Environment.GetFolderPath(Environment.SpecialFolder.Windows));

Console.WriteLine("ProgramFiles - {0}", Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles));

Console.WriteLine("System - {0}", Environment.GetFolderPath(Environment.SpecialFolder.System));

Output –

My Documents - D:\Users\mitesh\Documents

My Videos - D:\Users\mitesh\Videos

Windows - C:\WINDOWS

ProgramFiles - C:\Program Files

System - C:\WINDOWS\system32

//Enumerates all SpecialFolders available in Enviroment.SpecialFolder enum

foreach (var specialFolder in Enum.GetValues(typeof(Environment.SpecialFolder)))

    Console.WriteLine(specialFolder);

Output –

Desktop

Programs

MyDocuments

Favorites

Startup

Recent

SendTo

StartMenu

…

…

…

See Also - 
Working with File Class in .Net (C#)
Performance Counters in .Net
Semaphore in Threading