InvalidArgument on outputfile in deflate stream

Question

I want to deflate a file using deflate stream.

Below is the code I am using.

using (oZipper = new DeflateStream(outputFile, CompressionMode.Compress))

Where oZipper is a filestream.

When I step into the line of code above (using (oZipper...), an exception is thrown:

Base stream is not writeable, InvalidArgumentException. Parameter: stream (outputFile, which is a filestream).

Any idea why this is? My code seems to be fine and I'm passing in the right stuff.

Thanks

Answer 1

How did you open the FileStream? It sounds like you've opened it for reading rather than writing.

EDIT: So that this is more of an answer...

GSS was opening a FileOutputStream using File.Create, but then closing the stream before using it to create the DeflateStream. That stopped DeflateStream from writing to the output stream, hence the problem. Removing the call to close solved the issue.