一个多任务应用程序。带有四个彩色转轮的应用程序，每个彩色转轮都按自己的线程运行。其中两个使用OnIdle函数；另外两个则作为独立的线程运行。-a multi-tasking applications. Color wheel with four applications, each color wheel has its own threads to run. Two of them use OnIdle function; The other two were used as the inde