Creating a Random File in C#

Question

I am creating a file of a specified size - I don\'t care what data is in it, although random would be nice. Currently I am doing this:

        var sizeInMB          


        

Answer 1

There's no faster way then taking advantage of the sparse file support built into NTFS, the file system for Windows used on hard disks. This code create a one gigabyte file in a fraction of a second:

using System;
using System.IO;

class Program {
    static void Main(string[] args) {
        using (var fs = new FileStream(@"c:\temp\onegigabyte.bin", FileMode.Create, FileAccess.Write, FileShare.None)) {
            fs.SetLength(1024 * 1024 * 1024);
        }
    }
}

When read, the file contains only zeros.