Cannot Access Closed Stream

Question

I\'m trying to use the Caching Application Block to cache some images (these images take a long time to render)

  BitmapSource bitmapSource; ///some bitmap s         


        

Answer 1

The problem is that the stream is closed (via Dispose()) at the end of the using block. You retain a reference to the closed stream.

Instead, save the contents of the stream to your cache:

_cache.Add(someId, stream.ToArray());

When you call the PngBitmapDecoder constructor, you'll have to create a new MemoryStream to read from that byte array.

Answer 2

but isn't _cache.Add() making a copy (via Serialization) before it exits?

Not necessarily. If it is "in process" it will just store the object reference; Stream isn't really very serializable anyway (a Stream is a hose, not a bucket).

You want to store the BLOB - not the Stream:

    _cache.Add(someId, stream.ToArray());

...

byte[] blob = _cache.GetData(someId);
if(blob != null) {
    using(Stream inStream = new MemoryStream(blob)) {
         // (read)
    } 
}