Why is there a memory leak when I do not .Dispose() Bitmaps that I .Save() to a MemoryStream?

Question

Say I create a Bitmap

Bitmap bitmap = new Bitmap(320, 200);

When I write it to some stream (in my case, it\'s a HttpResponseStream, as give

Answer 1

Bitmap class utilizes unmanaged resources. These resources are not related to the resources utilized by the memory stream class. You can just wrap the bitmap class in a using statement to dispose of the bitmap instance when you are finished with it.

Missed the latter part of your question. One way to "set it and forget it" is by creating a wrapper class that exposes the bitmap instance but implements a destructor that disposes of the bitmap instance. This destructor will mean the bitmap class is disposed of implicitly at garbage collection.

As a final note: Any object you instantiate that implements IDisposable MUST be disposed of by your code. Dipose will never be implicitly called. Even in your first example. Just because you save the data to a stream does not meam that memory has then been deallocated. Most of the time it is a good idea to dipose of an object within the same segment of code that instantiated it. This assists in easier to read code by boosting code transparency.