Implementing Finalize and Dispose to Clean Up Unmanaged Resources

I found some design patterns about implementing Dispose & Destructors in C#.

Class instances often encapsulate control over resources that are not managed by the runtime, such as window handles (HWND), database connections, and so on. Therefore, you should provide both an explicit and an implicit way to free those resources. Provide implicit control by implementing the protected Finalize on an object (destructor syntax in C# and C++). The garbage collector calls this method at some point after there are no longer any valid references to the object.

Implementing Finalize and Dispose to Clean Up Unmanaged Resources