本文共 2925 字，大约阅读时间需要 9 分钟。
适配器模式是连接两个不兼容接口的桥梁，主要分为三种：类适配器、对象适配器以及接口适配器，本文根据所给的例子使用matlab语言对三种适配器进行实现。
已有的接口和类（AC220V）：
IAC220V.m
classdef IAC220V < handle methods(Abstract) getAC220V(~); endend
AC220V.m
classdef AC220V < IAC220V properties isAC = true; voltage = 220; end methods function obj = AC220V(voltage,isAC) obj.isAC = isAC; obj.voltage = voltage; end function [voltage,isAC] = getAC220V(obj) voltage = obj.voltage; isAC = obj.isAC; end endend
目标接口：（DC5V，注意两者的方法签名是不同的）
classdef IDC5V < handle methods(Abstract) getDC5V(~); endend
类适配器（将AC220V转化成DC5V）:
classdef ClassAdapter < AC220V & IDC5V methods function obj = ClassAdapter(voltage,isAC) obj = obj@AC220V(voltage,isAC); end function [new_voltage,new_isAC] = getDC5V(obj) [voltage,isAC] = obj.getAC220V(); new_voltage = 0; new_isAC = false; if(isAC) new_voltage = voltage / 44; new_isAC = false; end end endend
对象适配器：
classdef ObjAdapter < IDC5V properties pAC220 end methods function obj = ObjAdapter(pAC220) if(metaclass(pAC220) <= ?IAC220V) obj.pAC220 = pAC220; end end function [new_voltage,new_isAC] = getDC5V(obj) new_voltage = 0; new_isAC = false; if(~isempty(obj.pAC220)) [voltage,isAC] = obj.pAC220.getAC220V(); if(isAC) new_voltage = voltage / 44; new_isAC = false; end end end endend
接口适配器：
IDCOutput.m (定义通用输出接口)
classdef IDCOutput < handle methods(Abstract) getDC5V(~); getDC12V(~); endend
IAdapter.m（定义默认适配器接口）
classdef IAdapter < IDCOutput properties power end methods function obj = IAdapter(power) obj.power = power; end function [voltage,isAC] = getDC5V(~) voltage = 0; isAC = false; end function [voltage,isAC] = getDC12V(~) voltage = 0; isAC = false; end endend
AC220VAdapter.m (定义具体适配器方法，AC220V输入为例)
classdef AC220VAdapter < IAdapter methods function obj = AC220VAdapter(pAC220V) obj = obj@IAdapter(pAC220V); end function [new_voltage,new_isAC] = getDC5V(obj) new_voltage = 0; new_isAC = false; if(~isempty(obj.power)) [voltage,isAC] = obj.power.getAC220V(); if(isAC) new_voltage = voltage / 44; new_isAC = false; end end end endend
测试代码
a = ClassAdapter(220,true);disp(a.getDC5V()); b = ObjAdapter(AC220V(223,true));disp(b.getDC5V()); c = AC220VAdapter(AC220V(221,true));disp(c.getDC5V())
转载地址：http://rmkki.baihongyu.com/