[HttpGet] public IActionResult DownloadCsv() { // 1. Prepare your data (example) byte[] csvData = GetCsvByteArray(); // Your logic to get byte[] // 2. Define the MIME type for CSV string contentType = "text/csv"; // 3. Define the desired filename string fileName = "Report.csv"; // 4. Return the file return File(csvData, contentType, fileName); } Use code with caution. Key Components for Success
: If you are generating large CSVs, consider using a MemoryStream instead of a raw byte array to avoid high memory overhead. Generating the Byte Array from Data download csv file from byte array c#
The most straightforward way to implement this in an ASP.NET Core or MVC controller is by using the built-in File() method. [HttpGet] public IActionResult DownloadCsv() { // 1
In C#, downloading a CSV file from a byte array is a standard task typically handled within an ASP.NET Core or MVC controller. By returning a FileResult , you can signal the browser to treat the incoming byte stream as a downloadable attachment with a specific filename and MIME type. Direct Method: Using the Controller File Method Define the desired filename string fileName = "Report
: The File() helper automatically sets the Content-Disposition header to attachment , which triggers the "Save As" dialog in the browser instead of trying to display the text directly.
: Always use text/csv for CSV files. This tells the browser what kind of data it is receiving.
c# - Returning CSV from .NET Core controller - Stack Overflow