Checking if a stream is empty

Question

I am trying to deserialize a XML-file. I need to check if the XML-file stream is empty before tying to deserialize it.

IsolatedStorageFileStream isfs1 = new IsolatedStorageFileStream("test.xml", 
    FileMode.Open, FileAccess.Read, isf);

// Deserialize the XML to an object
Settings s = new Settings();
SoapFormatter SF= new SoapFormatter();
s = (Settings) SF.Deserialize(isfs1); 

How can I check if isfs1 empty or not?

Gaudet

Answer 1

Check the Length property of the stream.

Length represents the number of bytes currently in the file.

If it is 0, the file is empty.

Municipalize

Answer 2

If your file is in UTF-8 format, it's size is at least 3 because of BOM(Byte Order Mark). So checking the length > 0 will return true even if your file is empty.

Rarely

so? what's the solution? – Alfieri

Answer 3

Would IsolatedStorageFileStream.Length work?

if (isfs1.Length > 0) {
  // isfs1 isn't empty.
}

Roberts

Answer 4

If you construct empty zip archive memory stream it have 22 bytes in empty state.

MemoryStream memoryStream = new MemoryStream();
using (ZipArchive zip = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
    // no content added
}
memoryStream.Length // have value of 22

Obvert

Answer 5

if isfs1.Length =0 means the stream is empty

Corn