责任链模式

#include <iostream>
#include <string>
#include <sstream>
using namespace std;

template <class T>
string MyConvertToString(T value) {
    stringstream ss;
    ss << value;
    return ss.str();
}

//顶层的抽象类,规范了击鼓传花的组合能力
class Handle {
public:
    void setSuccessor(Handle *pSuccessor){
        this->m_pHandle = pSuccessor;
    }
    virtual string handleFeeRequest(double fee) = 0;
protected:
    Handle* m_pHandle;
};

class PrjManager :public Handle {
public:
    string handleFeeRequest(double fee) {
        string strTemp = "";
        if (fee < 500) {
            strTemp = "项目经理同意" + MyConvertToString(fee) + "费用";
            return strTemp;
        }
        else {
            if (this->m_pHandle != nullptr) {
                return m_pHandle->handleFeeRequest(fee);
            }

        }
        return strTemp;
        
    }
};

class DepManager :public Handle {
public:
    string handleFeeRequest(double fee) {
        string strTemp = "";
        if (fee>=500 &&fee < 1000) {
            strTemp = "部门经理同意" + MyConvertToString(fee) + "费用";
            return strTemp;
        }
        else {
            if (this->m_pHandle != nullptr) {
                return m_pHandle->handleFeeRequest(fee);
            }

        }
        return strTemp;

    }
};

class CEOManager :public Handle {
public:
    string handleFeeRequest(double fee) {
        string strTemp = "";
        if (fee >= 1000) {
            strTemp = "CEO经理同意" + MyConvertToString(fee) + "费用";
            return strTemp;
        }
        else {
            if (this->m_pHandle != nullptr) {
                return m_pHandle->handleFeeRequest(fee);
            }

        }
        return strTemp;

    }
};
int main(void) {
    //先要组装我们的责任链
    Handle* pH1 = new PrjManager;
    Handle* pH2 = new DepManager;
    Handle* pH3 = new CEOManager;
    pH1->setSuccessor(pH2);
    pH2->setSuccessor(pH3);
    cout << pH1->handleFeeRequest(128) << endl;
    cout << pH1->handleFeeRequest(512) << endl;
    cout << pH1->handleFeeRequest(1024) << endl;
    system("pause");
    return 0;
}