编译都没过，发生点事，心有点乱
随便看看就好
state.h
#ifndef _STATE_H
#define _STATE_H
#include <iostream>
using namespace std;
class Context
{
public:
Context() {
}
Context(State* state) : _state(state) {
}
~Context() {
}
void OperationInterface() {
_state->OperationInterface(this);
}
void OperationChangeState() {
_state->OperationChangeState(this);
}
private:
friend class State;
bool ChangeState(State* state) {
_state = state;
return true;
}
private:
State* _state;
};
class State
{
public:
State() {
}
virtual ~State() {
}
virtual void OperationInterface(Context *)=0;
virtual void OperationChangeState(Context *)=0;
protected:
bool ChangeState(Context* con,State* st) {
con->ChangeState(st);
return true;
}
};
class ConcreteStateA : public State
{
public:
ConcreteStateA() {
}
virtual ~ConcreteStateA() {
}
virtual void OperationInterface(Context*) {
cout << "ConcreteStateA:OperationInterface" << endl;
}
virtual void OperationChangeState(Context* con) {
OperationInterface(con);
ChangeState(con, new ConcreteStateB());
}
};
class ConcreteStateB : public State
{
public:
ConcreteStateB() {
}
virtual ~ConcreteStateB() {
}
virtual void OperationInterface(Context*) {
cout << "ConcreteStateB:OperationInterface" << endl;
}
virtual void OperationChangeState(Context* con) {
OperationInterface(con);
ChangeState(con, new ConcreteStateA());
}
};
#endif // _STATE_H
state.cpp
#include "state.h"
int main()
{
State* st = new ConcreteStateA();
Context* con = new Context(st);
con->OperationInterface();
con->OperationInterface();
con->OperationInterface();
return 0;
}
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