How to Create MFC Events

The MFC Library provides an evolution of the Exception Handling Model of plain C++. In Visual C++ the user is able to define custom events when errors occur in a program. The event in question can be a beep, some other notification or the termination of a thread. MFC Events, like the example code given below, are appropriate for mission-critical Visual C++ applications.

Things You'll Need

• Microsoft Visual Studio

Instructions

1. Give the following declaration a global scope. If you are using a dedicated header file for all your declarations include the statement below at the top of all declarations in that header file:
   
   int CODERSOURCEMSG;
   

2. Declare the prototype of the handler function that wraps around the event in the appropriate module. Use the following signature:
   
   afx_msg void onCODERSOURCEMSG();
   

3. Write the handler function for the event:
   
   void onCODERSOURCEMSG()
   
   {
   
   // Insert the code of the event here
   
   }
   
   

4. Create a Message Map. To find out how message maps are created in the Microsoft Visual Studio, Visual C++, read eHow article "How to Create Message Maps in MFC". Add the following macro in the message map:
   
   ON_REGISTERED_MESSAGE(CODERSOURCEMSG, onCODERSOURCEMSG)
   
   

5. Insert the following line in all the critical, error-prone places in your source code where you want each of the MFC events raised:
   
   PostMessage(CODERSOURCEMSG);
   

Resources

• The MSDN Library is an essential resource for developers.
• DevCentral has articles and tutorials.
• FunctionX provides tutorials and links on various computer languages.