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How To Use The HandleMessage Method In Windows Applications

How can I use HandleMessage method? I have loop and I can not click to components on runtime. How can our application receive clicks on the components when I have a loop? How can I receive user inputs on heavy iterations and keep the user interface responsive? Let’s answer these questions.

What is the HandleMessage Method ?

HandleMessage Method (Vcl::Forms::TApplication::HandleMessage) is a VCL method that interrupts the execution of an application while Windows processes a message in the Windows message queue. HandleMessage interrupts the execution of the application so that Windows can process a single message from the Windows message queue before returning control to the application. If the message queue is empty, HandleMessage generates an OnIdle event and starts the process of updating the actions in the application.

Note that  If the application goes idle, HandleMessage may take a long time to return. Therefore, do not call HandleMessage when waiting for something message-based while priority actions are also being processed. Instead, call ProcessMessages when processing more than just messages.

What is the syntax of the HandleMessage Method ?

Here is the syntax of the HandleMessage method,

What is a simple example of using the C++ HandleMessage Method ?

Here is the full example of using the C++ ProcessMessages Method

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About author

33+ years of coding with more than 30+ programming languages, mostly C++ on Windows, Android, Mac-OS, iOS, Linux and some other operating systems. Dr. Yilmaz Yoru was born in 1974, Eskisehir-Turkey. He graduated from the department of Mechanical Engineering of Eskisehir Osmangazi University in 1997. One year later he started to work in the same university as an assistant. He received his MSc and PhD degrees from the same department of the same university. He has married and he is a father of a son. Some of his interests are Programming, Thermodynamics, Fluid Mechanics and Artificial Intelligence. He also likes the graphical 2D & 3D design and high-end innovations.
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