Application of member function pointer the callback mechanism inside the UIButton (iii)

main.cpp//basic////Created by, on 15/1/9.//Copyright (c) 2015 Huangyongrui. All rights reserved.//#include <iostream>using namespace Std;class uibutton;//struct nsobject{//class bool INI for memory management    T () {return true;    }};//Hero class struct hero:public nsobject{void Move (uibutton* button) {cout << "hero moved" << Endl;  The alias of the}};//member function pointer, typedef void (nsobject::* FUNC) (uibutton*), #pragma the variable write permission in the struct is public by default. Class, do not write permissions, the default is private. C + + inheritance is a single colon: public is publicly inheriting struct UIButton:p ublic nsobject{Private://member variable is generally private, and then gives it a public set Get interface method int _tag    ; NSObject *_target;//This just pointer should also be created for him, where to create? Initialize method inside?? No, because if you want 2 heroes, wouldn't it be to create 2 buttons??        The FUNC _func should be passed in when the button is created; Public://For OC There is a class method for creating objects + #pragma dynamically passing in objects and methods as long as the address of the callback method satisfying this format can be passed static uibutton* Buttonwithtarget (NSObject *ta Rget,func FUNC) {//Create object//The first step is to open up space UIButton *m_button = new uibutton;//here is not like OC Alloc created counter on +1, there is no concept of reference counter in C + + so there is no minus one ...     Open space is new, release on delete           The second step is to initialize the IF (M_button->initwithtarget (Target,func)) {//pointer access method with arrows///If it is in OC it will also call Autor        Elease ()//third returns the pointer of the object return M_button;        }//If initialization failed//destruction of space delete M_button;                Prevent wild pointer M_button = nullptr;            return NULL; }//Return Boolean to determine if initialization succeeded bool Initwithtarget (NSObject *target,func FUNC) {#pragma note the principle subclass initialization must first call the parent class's initialization method ( Because the initialization of the parent class may assign a value to a variable, if you do not invoke the initialization of the parent class, then you will inherit no value) if (!        Nsobject::init ()) {return false;//parent class initialization failed}//Initialize subclass own things _target = target;            _func = func;//return true;    }//member variable set get method int Gettag () {return _tag; } void Settag (int tag) {//If there is such a method in oc Self.tag = tag; Is there a problem? Yes!        Dead Loop!    _tag = tag;    }//Analog click button when void Touch () {cout << "button is in point" << Endl; }//I now want the hero to move in the point (not to print a word, andIs the heroic object calls his own Move method) void Touch1 () {#pragma This function pointer requires a parameter parameter type is UIButton takes itself out into the callback function (_target->* _func) (                this);    void func (uibutton*); }};//struct plane:public nsobject{void Fly (uibutton* button) {cout << "aircraft??    Flying "<< Endl;    }};//main function int main () {#pragma problem//But now I want to put the button on the plane and click Let the plane move so I'm not going to change the source file hero to a plane?? That means I want to button general, what to do?        The object that the button represents can only be retrieved dynamically, and the execution method also needs to dynamically acquire _hero-a move ();    Hero objects should be presented as arguments, but the parameter types cannot be fixed as heroes, but NSObject types, whether aircraft tank cannons can be passed in//create heroes hero* Hero = new Hero;        Create button UIButton *button = Uibutton::buttonwithtarget (Hero, (FUNC) &hero::move);//cast button->touch1 ();    Create aircraft object Plane *plane = new Plane;    UIButton *button2 = uibutton::buttonwithtarget (plane, (FUNC) &plane::fly);        Button2, Touch1 (); The method selector is actually a macro #define selector (SET) (FUNC) &AMP;SET//set macro parameter//create button UIButton *button3 = Uibutton::buttonwit Htarget (Hero, selector (Hero::Move));        Button3->touch1 (); return 0;}

Application of member function pointer the callback mechanism inside the UIButton (iii)