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?

score 54 · Accepted Answer · answered May 30 '11 at 19:09

54

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.

answered May 30 '11 at 19:09

Oded

489,969
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1,009

score 7 · Answer 2 · answered Jul 24 '14 at 15:41

7

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.

answered Jul 24 '14 at 15:41

Bogdan

71
1
1

2

so? what's the solution? – Ramon Dias Apr 21 '22 at 20:53

score 2 · Answer 3 · answered May 30 '11 at 19:10

2

Would IsolatedStorageFileStream.Length work?

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

answered May 30 '11 at 19:10

King Skippus

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score 2 · Answer 4 · answered Jun 18 '21 at 12:34

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

score 0 · Answer 5 · answered May 30 '11 at 19:16

0

if isfs1.Length =0 means the stream is empty

answered May 30 '11 at 19:16

DeveloperX

4,633
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Checking if a stream is empty

5 Answers5