C++虚函数和函数指针一起使用

C++虚函数和函数指针一起使用，写起来有点麻烦。

下面贴出一份示例代码，可作参考。(需要支持C++11编译)

 1 #include <stdio.h>
 2 #include <list>
 3 using namespace std;
 4
 5 class VirtualWithCallBack {
 6 public:
 7     using CallBack = void(VirtualWithCallBack::*)(int);
 8
 9 public:
10     virtual void testCallBack(int arg) = 0;
11
12     virtual CallBack getCallBack() const = 0;
13 };
14
15 class VirtualWithCallBackSample1 : public VirtualWithCallBack {
16 public:
17     VirtualWithCallBackSample1() {
18         callBack = &VirtualWithCallBack::testCallBack;
19     }
20
21 public:
22     void testCallBack(int arg) override {
23         printf("This is virtual call 1 : arg = %d\n", arg);
24     }
25
26     CallBack getCallBack() const override {
27         return callBack;
28     }
29
30 private:
31     CallBack callBack = nullptr;
32 };
33
34 class VirtualWithCallBackSample2 : public VirtualWithCallBack {
35 public:
36     VirtualWithCallBackSample2() {
37         callBack = &VirtualWithCallBack::testCallBack;
38     }
39
40 public:
41     void testCallBack(int arg) override {
42         printf("This is virtual call 2 : arg = %d\n", arg);
43     }
44
45     CallBack getCallBack() const override {
46         return callBack;
47     }
48
49 private:
50     CallBack callBack = nullptr;
51 };
52
53 class VirtualCaller {
54 public:
55     void push(VirtualWithCallBack* callBack) {
56         callBackList.push_back(callBack);
57     }
58
59     void run() {
60         for (auto r : callBackList) {
61             (r->*(r->getCallBack()))(99);
62         }
63     }
64
65 private:
66     list<VirtualWithCallBack*> callBackList;
67 };
68
69 int main() {
70     VirtualCaller caller;
71     caller.push(new VirtualWithCallBackSample1());
72     caller.push(new VirtualWithCallBackSample2());
73     caller.run();
74     return 0;
75 }

运行结果