模板方法模式,定義一個操作中的算法的骨架,而將一些步驟延遲到子類中。模板方法使得子類可以不改變一個算法的結構即可重定義該算法的某些特定步驟。
AbstractClass實現了一個模板方法,定義了算法的骨架,具體子類將重定義PrimitiveOperation以實現一個算法的步驟。
ConcreteClass實現PrimitiveOperation以完成算法中與特定子類相關的步驟。每一個AbstractClass可以有多個ConcreteClass與之對應。
參照大話設計模式上,用C++對其進行重新實現,代碼如下:
//抽象父類
#ifndef __TEST_PAPER_H__
#define __TEST_PAPER_H__
#include "stdio.h"
class TestPaper
{
public:
TestPaper() {}
virtual ~TestPaper() {}
void TestQuestion1()//d
{
printf("計算機能直接執行的程序是[%s]\nA.源程序 B.目標程序 C.彙編程序 D.可執行程序\n", Answer1());
}
void TestQuestion2()//a
{
printf("C源程序中不能表示的數制是[%s]\nA.二進制 B.八進制 C.十進制 D.十六進制\n", Answer2());
}
void TestQuestion3()//a
{
printf("[%s]是構成C語言程序的基本單位。\nA.函數 B.過程 C.子程序 D.子例程\n", Answer3() );
}
virtual char* Answer1() = 0;
virtual char* Answer2() = 0;
virtual char* Answer3() = 0;
};
#endif // !__TEST_PAPER_H__
#ifndef __TEST_PAPERA_H__
#define __TEST_PAPERA_H__
#include "TestPaper.h"
class TestPaperA : public TestPaper
{
public:
virtual char* Answer1()
{
return "D";
}
virtual char* Answer2()
{
return "A";
}
virtual char* Answer3()
{
return "A";
}
};
#endif // !__TEST_PAPERA_H__
#ifndef __TEST_PAPERB_H__
#define __TEST_PAPERB_H__
#include "TestPaper.h"
class TestPaperB : public TestPaper
{
public:
virtual char* Answer1()
{
return "D";
}
virtual char* Answer2()
{
return "A";
}
virtual char* Answer3()
{
return "A";
}
};
#endif // !__TEST_PAPERB_H__
//客戶端代碼
#include "windows.h"
#include "tchar.h"
#include "TestPaperA.h"
#include "TestPaperB.h"
int _tmain(int argc, TCHAR* argv[])
{
printf("Mr Wang的試卷:\n");
TestPaper *studentA = new TestPaperA();
studentA->TestQuestion1();
studentA->TestQuestion2();
studentA->TestQuestion3();
if (studentA)
{
delete studentA;
studentA = NULL;
}
printf("\n\n");
printf("Mrs Yu的試卷:\n");
TestPaper *studentB = new TestPaperB();
studentB->TestQuestion1();
studentB->TestQuestion2();
studentB->TestQuestion3();
if (studentB)
{
delete studentB;
studentB = NULL;
}
}
運行結果如下: