实现了一个写字板应用程序，主要介绍多文档模板的程序框架，启动屏，快捷工具栏，状态栏的相关知识。- Realized to write the board application procedure, mainly introduced the multi- documents template the procedure frame, the start screen, quick tool fence, condition fence related knowledge.

DFIELD5 is an interactive tool for studying single first order differential equations. When DFIELD5 is executed, a DFIELD5 Setup window is opened. The user may enter the differential equation and specify a display window using the interactive control