Casting stream to filestream

Question

Possible Duplicate:
Convert a Stream to a FileStream in C#

My question is regarding the cast of stream to FileStream ...

Basically I need to do that to get the name of the file, because if I have just an object Stream it doesn't have the Name property, when FileStream does ...

So how to do it properly, how to cast Stream object to FileStream ...?

Another problem is that this stream comes from webResponse.GetResponseStream() and if I cast it to FileStream I get it empty. Basically I could also use stream but i need to get the file name.

I'm using 3.5

Any ideas?

Read: http://stackoverflow.com/questions/3769067/convert-a-stream-to-a-filestream-in-c-sharp — Mate, Nov 30 '12 at 07:31
What would you want to do if the stream isn't *actually* a `FileStream`? — Jon Skeet, Nov 30 '12 at 07:33
If use .net 4.0 , use Stream.CopyTo() . Doc: http://msdn.microsoft.com/en-us/library/dd782932.aspx — Mate, Nov 30 '12 at 07:35

score 24 · Accepted Answer · answered Nov 30 '12 at 07:32

Use the as operator to perform the cast, if the Stream is not actually a FileStream, null will be returned instead of throwing an exception.

Stream stream = ...;
FileStream fileStream = stream as FileStream;

if(fileStream != null)
{
    //It was really a file stream, get your information here
}
else
{
    //The stream was not a file stream, do whatever is required in that case
}

score 4 · Answer 2 · answered Nov 30 '12 at 07:32

4

Assuming the stream actually is a file stream, the following should do the trick:

var name = ((FileStream)stream).Name;

answered Nov 30 '12 at 07:32

Teppic

2,506
20
26

Dennis · Answer 3 · 2012-11-30T07:44:42.617

Option 1. If you're sure, that Stream object is a FileStream:

var fileStream = (FileStream)stream;

Option 2. If you're not sure, that Stream object is a FileStream, but if it is, it will be useful:

var fileStream = stream as FileStream;
if (fileStream != null)
{
    // specific stuff here
}

Note, that casting to more specific type usually is a signal to look carefully at your code and, possibly, to refactor it.

Casting stream to filestream

3 Answers3

Linked