c# stream to base64 code example
Example 1: Base64String to stream c#
var bytes = Convert.FromBase64String(base64encodedstring);
var contents = new StreamContent(new MemoryStream(bytes));
// Whatever else needs to be done here.
Example 2: convert stream to base64 string c#
You can also encode bytes to Base64. How to get this from a stream see here: How to convert an Stream into a byte[] in C#?
Or I think it should be also possible to use the .ToString() method and encode this.