Services
Technology Web App Development Mobile App Development Windows App Development Database Development UI/UX Development Cloud Development SEO Digital Marketing Guest Posting Content Writing Artificial Intelligence Data Science ERP Development CRM Development CMS Development LMS Development Business Listing Blockchain Technology Startup Promotion AI Tools Integration
Products
Data Converter Cleaner TUC - Unit Converter Import Export Survey Manager Tweet Controller
Developer
Article Blog Forum Interview Beginner News Startup Quiz
Users
Career
Apply Job Internship
Pricing
Login Sign Up Get a Quote

forum

Home Forums How do you list and filter files using LINQ? – MindStick
Ask Question

1 Answers

Anubhav Sharma
Anubhav Sharma 22 May 2025
Report Abuse

To list and filter files using LINQ, you can combine System.IO with LINQ queries to efficiently query file metadata (like name, size, extension, etc.).

Example: List All Files in a Directory

using System.IO;
using System.Linq;

string folderPath = @"C:\Uploads";

var files = Directory.GetFiles(folderPath)
    .Select(f => new FileInfo(f))
    .ToList();

Filter Examples Using LINQ

1. Filter by Extension

var pdfFiles = files
    .Where(f => f.Extension.Equals(".pdf", StringComparison.OrdinalIgnoreCase))
    .ToList();

2. Filter by File Size (e.g., files > 1 MB)

var largeFiles = files
    .Where(f => f.Length > 1 * 1024 * 1024) // > 1MB
    .ToList();

3. Filter by Creation Date

var recentFiles = files
    .Where(f => f.CreationTime >= DateTime.Today.AddDays(-7)) // last 7 days
    .ToList();

4. Filter by Name Pattern

var matchingFiles = files
    .Where(f => f.Name.Contains("report", StringComparison.OrdinalIgnoreCase))
    .ToList();

5. Combine Filters

var filtered = files
    .Where(f =>
        f.Extension == ".txt" &&
        f.Length < 500_000 &&
        f.CreationTime > DateTime.Today.AddMonths(-1))
    .ToList();

Project to Custom DTO

var fileList = files.Select(f => new
{
    f.Name,
    f.Extension,
    SizeKB = f.Length / 1024,
    Created = f.CreationTime
}).ToList();

Bonus: Recursive File Listing

var allFiles = Directory.GetFiles(folderPath, "*.*", SearchOption.AllDirectories)
    .Select(f => new FileInfo(f))
    .ToList();
advertising
Markdown for AI

A clean, structured version of this page for AI assistants and LLMs.

Open .md