Cannot Access Closed Stream

.net, c#, caching-application-block, serialization

Solution

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)
    } 
}

Problem

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 source already created _cache /// Caching Application Block String someId; //id for this image, used as the key for the cache using (var stream = new MemoryStream()) { PngBitmapEncoder encoder = new PngBitmapEncoder(); encoder.Interlace = PngInterlaceOption.On; encoder.Frames.Add(BitmapFrame.Create(bitmapSource)); encoder.Save(stream); _cache.Add(someId, stream); } ``` And then load them using: ``` imStream = (Stream)_cache.GetData(someId)); if (imStream != null) { PngBitmapDecoder decoder = new PngBitmapDecoder(imStream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default); return decoder.Frames[0]; //return the bitmap source } ``` But during the load, i get the following exception at that "new PngBitmapDecoder" line: "Cannot access a closed Stream. I understand I closed the stream in the above code, but isn't _cache.Add() making a copy (via Serialization) before it exits? What's the correct process of serializing the stream? THanks!

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