abstract function class

基本解釋

Classes derived from the abstract class must implement the pure virtual member function or they, too, are abstract classes.
由抽象類(lèi)別衍生出來(lái)的類(lèi)別必須實(shí)作純虛擬成員函式，否則它們也是抽象類(lèi)別。
You open the file by calling the in function of the DL_Dxf object and passing a pointer to a class that inherits from the DL_CreationAdapter abstract class.
通過(guò)調(diào)用 DL_Dxf 對(duì)象的 in 函數(shù)竝將指針傳遞給一個(gè)繼承 DL_CreationAdapter 抽象類(lèi)來(lái)打開(kāi)此文件。
In a base class, abstract class is defined by declaring pure virtual function, a derived class must define all inherited pure virtual functions of its base classes to be concrete.
在基類(lèi)中可以通過(guò)將虛函數(shù)聲明爲(wèi)純虛函數(shù)的手段來(lái)定義抽象類(lèi)，強(qiáng)制派生類(lèi)在自己的類(lèi)定義中實(shí)現(xiàn)虛函數(shù)的具躰功能。