How to GetBytes() in C# with UTF8 encoding with BOM?

Question

I\'m having a problem with UTF8 encoding in my asp.net mvc 2 application in C#. I\'m trying let user download a simple text file from a string. I am trying to get bytes arra

Answer 1

Try like this:

public ActionResult Download()
{
    var data = Encoding.UTF8.GetBytes("some data");
    var result = Encoding.UTF8.GetPreamble().Concat(data).ToArray();
    return File(result, "application/csv", "foo.csv");
}

The reason is that the UTF8Encoding constructor that takes a boolean parameter doesn't do what you would expect:

byte[] bytes = new UTF8Encoding(true).GetBytes("a");

The resulting array would contain a single byte with the value of 97. There's no BOM because UTF8 doesn't require a BOM.