【摘要】 介绍了软件工程领域的技术同实际应用相结合的具体方法，并根据专业系统的特点提出了更合适的软件设计方法，以水利工程CAD为例，解释了面向对象技术中的抽象性、封装性、继承性、多态性等特征的具体应用以及实现的方法。该方法已通过实验验证，可适用于机械制造和建筑工程行业的CAD图形绘制开发系统。更多还原

【Abstract】 With the development of software science, new application system is becoming more and more complicated and changeable. This paper introduces the practical methods, which combine technologies in software engineering field with the practical system and puts forward to a more applicable design method . It takes the CAD system of water conservancy engineering as an example and explains the OOP’s technology, including encapsulation, inheritance, polymorphism and the corresponding application and the realizing method in detail. This method has been verified by an example .It is suitable for a large CAD software system in the mechanistic manufacturing and constructing engineering field.更多还原