How to find the file using C#?

Use the Directory.GetFiles and Directory.GetDirectories methods in C# to search for files in a directory structure. These methods provide powerful options to recursively search through subdirectories and apply search patterns.

Syntax

Following is the syntax for finding files using Directory.GetFiles −

string[] files = Directory.GetFiles(path, searchPattern, SearchOption.AllDirectories);

Following is the syntax for finding directories using Directory.GetDirectories −

string[] directories = Directory.GetDirectories(path, searchPattern, SearchOption.AllDirectories);

Parameters

• path − The directory path to search in
• searchPattern − The search string to match file/folder names (supports wildcards like * and ?)
• SearchOption − Specifies whether to search current directory only or include subdirectories

Using Directory.GetFiles to Find Files

Example - Finding Files with Specific Extension

using System;
using System.IO;

class Program {
   public static void Main() {
      // Create sample directory structure and files
      string basePath = @"C:\temp\TestFiles";
      Directory.CreateDirectory(basePath);
      Directory.CreateDirectory(Path.Combine(basePath, "SubFolder"));
      
      File.WriteAllText(Path.Combine(basePath, "file1.txt"), "content");
      File.WriteAllText(Path.Combine(basePath, "file2.xml"), "xml content");
      File.WriteAllText(Path.Combine(basePath, "SubFolder", "file3.txt"), "content");
      
      // Find all .txt files recursively
      string[] txtFiles = Directory.GetFiles(basePath, "*.txt", SearchOption.AllDirectories);
      
      Console.WriteLine("Found " + txtFiles.Length + " .txt files:");
      foreach (string file in txtFiles) {
         Console.WriteLine(file);
      }
      
      // Clean up
      Directory.Delete(basePath, true);
   }
}

The output of the above code is −

Found 2 .txt files:
C:\temp\TestFiles\file1.txt
C:\temp\TestFiles\SubFolder\file3.txt

Using Directory.GetDirectories to Find Folders

Example - Finding Directories with Pattern

using System;
using System.IO;

class Program {
   public static void Main() {
      // Create sample directory structure
      string basePath = @"C:\temp\TestDirs";
      Directory.CreateDirectory(basePath);
      Directory.CreateDirectory(Path.Combine(basePath, "xml_data"));
      Directory.CreateDirectory(Path.Combine(basePath, "json_data"));
      Directory.CreateDirectory(Path.Combine(basePath, "temp"));
      Directory.CreateDirectory(Path.Combine(basePath, "xml_data", "backup"));
      
      // Find directories containing "xml"
      string[] xmlDirs = Directory.GetDirectories(basePath, "*xml*", SearchOption.AllDirectories);
      
      Console.WriteLine("Found " + xmlDirs.Length + " directories containing 'xml':");
      foreach (string dir in xmlDirs) {
         Console.WriteLine(dir);
      }
      
      // Clean up
      Directory.Delete(basePath, true);
   }
}

The output of the above code is −

Found 1 directories containing 'xml':
C:\temp\TestDirs\xml_data

Using File.Exists to Check File Existence

Example - Checking if Specific File Exists

using System;
using System.IO;

class Program {
   public static void Main() {
      string filePath = @"C:\temp\sample.txt";
      
      // Create a sample file
      Directory.CreateDirectory(@"C:\temp");
      File.WriteAllText(filePath, "Sample content");
      
      // Check if file exists
      if (File.Exists(filePath)) {
         Console.WriteLine("File found: " + filePath);
         Console.WriteLine("File size: " + new FileInfo(filePath).Length + " bytes");
      } else {
         Console.WriteLine("File not found: " + filePath);
      }
      
      // Clean up
      File.Delete(filePath);
      Directory.Delete(@"C:\temp");
   }
}

The output of the above code is −

File found: C:\temp\sample.txt
File size: 14 bytes

SearchOption Values

Conclusion

Use Directory.GetFiles to find files and Directory.GetDirectories to find folders in C#. Both methods support search patterns with wildcards and can search recursively through subdirectories using SearchOption.AllDirectories. For checking specific file existence, use File.Exists.