说明：  VC中自动改变控件位置和大小的对话框类。在用VC开发应用程序时，经常会要做一些可以改变大小的对话框，而这个时候就要求对话框上的控件会随着对话框大小的改变而改变自己的位置和大小。
(VC automatically change the position and size controls the dialog class. In the VC development application, often Do something to change the size of the dialog box, and this time requires controls on the dialog with the Dialog box to change the size of the change in their position and size.)