using CsvHelper; using System.Globalization; using Microsoft.AspNetCore.Mvc; public class ExportController : ControllerBase { [HttpGet("download-csv")] public IActionResult DownloadCsv() { var data = new List { new User { Id = 1, Name = "Alice Smith", Email = "alice@example.com" }, new User { Id = 2, Name = "Bob Jones", Email = "bob@example.com" } }; using (var memoryStream = new MemoryStream()) using (var writer = new StreamWriter(memoryStream)) using (var csv = new CsvWriter(writer, CultureInfo.InvariantCulture)) { csv.WriteRecords(data); writer.Flush(); return File(memoryStream.ToArray(), "text/csv", "users_export.csv"); } } } Use code with caution. 2. The Native Way (No Libraries)
This guide covers the most efficient ways to generate CSV files and trigger browser downloads using C#. 1. Using CsvHelper (Recommended) c# export to csv and download
While you can manually join strings, using a library like is the industry standard. It handles special characters, commas in data, and complex mapping automatically. Install the NuGet Package dotnet add package CsvHelper Use code with caution. The Implementation using CsvHelper; using System
Use IEnumerable with yield to fetch data row-by-row from the database. Install the NuGet Package dotnet add package CsvHelper
Sometimes Excel fails to recognize UTF-8. Adding a Byte Order Mark (BOM) can fix this: var content = Encoding.UTF8.GetPreamble().Concat(csvData).ToArray(); 💡 Key Takeaway
For , use CsvHelper . It prevents the "broken column" bugs caused by commas or quotes in your data. For quick internal tools , a simple StringBuilder is often enough. To help you get the best performance, tell me: