typeid的用法-例子

#include "stdafx.h"
#include <typeinfo.h>
#include <iostream.h>
#include <string.h>

class grapicImage
{
protected:
 char name[80];
public:
 grapicImage()
 {
  strcpy(name,"grapicimage");
 }
 virtual void display()
 {
  cout<<"display a generic image"<<endl;
 }
 char * getName()
 {
  return name;
 }
};

class GifImage :public grapicImage
{
public:
 GifImage()
 {
  strcpy(name,"gifimage");
 }
 void display()
 {
  cout<<"display a gif image"<<endl;
 }
};

class  PICTImage :public grapicImage
{
public:
 PICTImage()
 {
  strcpy(name,"PICT image");
 }
 void display()
 {
  cout<<"display a pict image"<<endl;
 }
};

void ProcessFile(grapicImage* pImage)
{
 if(typeid(*pImage)==typeid(GifImage))
 {
  ((GifImage*)pImage)->display();
 }
 else
  if(typeid(*pImage)==typeid(PICTImage))
  {
   ((PICTImage*)pImage)->display();
  }
  else
  {
   cout << "Unknown type! " << (typeid(*pImage)).name() << endl;
  }
}

int main(int argc, char* argv[])
{
 

 grapicImage *gImage = new GifImage();
 grapicImage *pImage = new PICTImage();
 ProcessFile(gImage);
 ProcessFile(pImage);
 return 0;
}

 

程序运行结果如下：