Overview.NET is great platform, it speeds up the development process, you deal with your application logic and in most cases you don't need to know that there is whole Windows operating system down there. However sometimes you do need to program against Windows without the .NET assistance. As a Windows developer, you need to keep all your weapons ready, be it .NET, COM or C++ with the native Win32 API. In this article I am going to show how to deal with Windows Message based communication protocol within .NET application.
Windows MessagesIn traditional User32.dll based Windows application the Windows Messages mechanism serves as a communication channel among many parties. The Windows Operating System uses this mechanism to ask the Window to draw itself, to inform about environmental change or even to communicate a logoff event. The application itself uses this mechanism to create an event driven design model with a single thread or to communicate between threads. Other applications can use this mechanism with an application defined message (the WM_APP message range) to trigger a logical event, or even to pass memory buffer using the WM_COPYDATA. Windows In Windows Are Based On An Object Oriented MechanismOne of the impressive thing about the windows mechanism of Windows, considering its age and the fact that it was implemented with the C language in mind, is that is based on the Object Oriented paradigm. Each window is belong to a Window Class. The class is the factory of a window. The class defines the window's properties as well as the window's behavior. The properties are set using one of the predefined window class member such as the window's menu, or cursor. The behavior is defined by specifying the windows procedure address. The window procedure handles the incoming Windows Messages, which are in fact the methods of the window. Changing the Windows attributes can be made using the SetWindowLong/Ptr. Creating type fields (static) and instance fields can be made by allocating user-defined memory area for each Window class (static) and Window instance (dynamic) using the cbClsExtra and cbWndExtra fields of the WNDCLASS structure. Subclassing a Windows class can be achieved by changing the window procedure address to point to a custom function that handles the Windows Messages before it calls the original window procedure. You can subclass a Window instance or Window class (global subclassing). Read more: public: class Alon : IArchitect, IAzure, ICPP, ISmartHome, IHomeServer
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Windows MessagesIn traditional User32.dll based Windows application the Windows Messages mechanism serves as a communication channel among many parties. The Windows Operating System uses this mechanism to ask the Window to draw itself, to inform about environmental change or even to communicate a logoff event. The application itself uses this mechanism to create an event driven design model with a single thread or to communicate between threads. Other applications can use this mechanism with an application defined message (the WM_APP message range) to trigger a logical event, or even to pass memory buffer using the WM_COPYDATA. Windows In Windows Are Based On An Object Oriented MechanismOne of the impressive thing about the windows mechanism of Windows, considering its age and the fact that it was implemented with the C language in mind, is that is based on the Object Oriented paradigm. Each window is belong to a Window Class. The class is the factory of a window. The class defines the window's properties as well as the window's behavior. The properties are set using one of the predefined window class member such as the window's menu, or cursor. The behavior is defined by specifying the windows procedure address. The window procedure handles the incoming Windows Messages, which are in fact the methods of the window. Changing the Windows attributes can be made using the SetWindowLong/Ptr. Creating type fields (static) and instance fields can be made by allocating user-defined memory area for each Window class (static) and Window instance (dynamic) using the cbClsExtra and cbWndExtra fields of the WNDCLASS structure. Subclassing a Windows class can be achieved by changing the window procedure address to point to a custom function that handles the Windows Messages before it calls the original window procedure. You can subclass a Window instance or Window class (global subclassing). Read more: public: class Alon : IArchitect, IAzure, ICPP, ISmartHome, IHomeServer
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