说明：  实验物体沿正弦曲线运动 1.实验目的 （1）初步熟悉应用windows API函数进行编程的入门,编写简单的Windows应用程序,建立窗口、句丙，认知消息循环、画笔、画刷，建立坐标。 （2）实验物体沿正弦曲线运动,该物体为一个大小渐变以及颜色都会变化的小球,变化的的转折点是正弦曲线一个完整周期(2∏)里的四分之一,二分之一,和四分之三处(即∏／4 ∏／2 3∏／4处) （3）通过放胶片电影的原理实现物体沿正弦曲线运动。胶片电影有原理是在规定时间（一般为1秒）播放24幅连续的画面，由于人的视觉暂留，所以人们在观看电影时，看到的就不是一幅一幅的画面，而是丰富精彩的场景。本程序通过调用sleep（100）函数使程序暂停0.1秒。当i<100时调用InvalidateRect刷新用户区发送WM_PAINT消息,这样使得WM_PAINT处理程序不断被调用,像电影播放原理那样呈现动态效果。
(experimental objects movement along a sinusoidal curve. Experiment (1) familiar with the preliminary application windows API programming entry, to prepare a simple Windows application that creates a window sentence C, cognitive news cycle, brushes, brush painting and establish coordinates. (2) experimental objects along the sinusoidal curve movement, the object of a size and color will gradually change to the small ball, a turning point in changing the sine curve is a complete cycle (2 )'s quarter, half and three quarters (the/4/2 3/4) (3) through the release filmed achieve the principle objects along the sinusoidal curve campaign. Filmed an addict is in a specified time (usually a second) broadcast 24 consecutive images, the visual temporary stay, so people watching the film )