Where do I find good material on the Observer design pattern?

Where to find good material to study obs开发者_JS百科erver pattern? I need some examples, of code and also pictures of modelled situations

Head first design patterns is the book for you. There are loads of pictures in this book.

Here is the code for observer pattern and other patterns (JAVA).

Most of the chapter on the Observer pattern from the Design Patterns in Java book can be viewed on Google Books.

Same thing for Head First Design patterns, by the way.

alt text http://bks6.books.google.com/books?id=S5ebGvuLJqQC&printsec=frontcover&img=1&zoom=5&edge=curl&sig=ACfU3U3OFvA14Y4IKb9iZ-eH664YW15Fbg alt text http://bks1.books.google.com/books?id=LjJcCnNf92kC&printsec=frontcover&img=1&zoom=5&edge=curl&sig=ACfU3U1t6E1H5cFgQvMyhE8hkYJk-Rt0Lg

For starters: Observer on Wikipedia. It includes examples in Java, Python and C++, and lots of links.

Here is a C# example & UML diagram.

Here's a nice dzone article about the observer pattern. You may also like Non-software examples of Software Design Patterns.