通过函数指针调用C ++类方法 [英] Calling C++ class methods via a function pointer

问题描述

如何获取类成员函数的函数指针，然后使用特定对象调用该成员函数？我想写：

  class Dog：Animal 
 {
 Dog 
 void bark（）; 
} 
 
 ... 
狗* pDog = new Dog（）; 
 BarkFunction pBark =& Dog :: bark; 
（* pBark）（pDog）; 
 ... 
  

此外，如果可能，我想通过指针调用构造函数

  NewAnimalFunction pNew =& Dog :: Dog; 
 Animal * pAnimal =（* pNew）（）;这是可能的吗？如果是这样，这是最好的方法是什么？
 
 
解决方案
阅读此详细：
 
 
 
 // 1定义函数指针并初始化为NULL 
  int（TMyClass :: * pt2ConstMember）（float，char，char）const = NULL; 
  
 // C ++ 
  class TMyClass 
 {
 public：
 int DoIt（float a，char b，char c）{cout< TMyClass :: DoIt< endl; return a + b + c;}; 
 int DoMore（float a，char b，char c）const 
 {cout< TMyClass :: DoMore< endl; return a-b + c; }; 
 
 / * TMyClass的更多* / 
}; 
 pt2ConstMember =& TMyClass :: DoIt; // note：< pt2Member>也可以合法地指向& DoMore 
 
 //使用函数指针调用函数
 
（* this。* pt2ConstMember）（12，'a'，'b'）; 
  
 
How do I obtain a function pointer for a class member function, and later call that member function with a specific object?  I’d like to write:
class Dog : Animal
{
    Dog ();
    void bark ();
}

…
Dog* pDog = new Dog ();
BarkFunction pBark = &Dog::bark;
(*pBark) (pDog);
…
Also, if possible, I’d like to invoke the constructor via a pointer as well:
NewAnimalFunction pNew = &Dog::Dog;
Animal* pAnimal = (*pNew)();
Is this possible, and if so, what is the preferred way to do this?
解决方案
Read this for detail :

// 1 define a function pointer and initialize to NULL
int (TMyClass::*pt2ConstMember)(float, char, char) const = NULL;
// C++
class TMyClass
{
public:
   int DoIt(float a, char b, char c){ cout << "TMyClass::DoIt"<< endl; return a+b+c;};
   int DoMore(float a, char b, char c) const
         { cout << "TMyClass::DoMore" << endl; return a-b+c; };

   /* more of TMyClass */
};
pt2ConstMember = &TMyClass::DoIt; // note: <pt2Member> may also legally point to &DoMore

// Calling Function using Function Pointer

(*this.*pt2ConstMember)(12, 'a', 'b');


                        
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