openxml spreadsheat save-as

Accepted answer +10 upvotes

To my knowledge there is no built in way to change the filename, but since one way to edit the file is to use streams you can easily give the name of the file you want when writing out the contents of a stream:

byte[] byteArray = File.ReadAllBytes("C:\temp\oldName.xltx");
using (MemoryStream stream = new MemoryStream())
{
    stream.Write(byteArray, 0, (int)byteArray.Length);
    using (SpreadsheetDocument spreadsheetDoc = SpreadsheetDocument.Open(stream, true))
    {
       // Do work here
    }
    File.WriteAllBytes("C:\temp\newName.xlsx", stream.ToArray()); 
}

There are other ways to change the name as well, like when returning the file to a user in an ASP.NET MVC web application, but it depends on what you are trying to do.