對象創建模式
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工廠模式
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原始程序
/*文件分割程序*/
class ISplitter{
public:
virtual void split()=0;
virtual ~ISplitter(){}
};
class BinarySplitter : public ISplitter{
};
class TxtSplitter: public ISplitter{
};
class PictureSplitter: public ISplitter{
};
class VideoSplitter: public ISplitter{
};
//文件分割
class MainForm : public Form
{
TextBox* txtFilePath;
TextBox* txtFileNumber;
ProgressBar* progressBar;
public:
void Button1_Click(){
ISplitter * splitter=
new BinarySplitter();//依賴具體類，細節依賴
splitter->split();
}
};
重構程序
//抽象類
class ISplitter{
public:
virtual void split()=0;
virtual ~ISplitter(){}
};
//工廠基類
class SplitterFactory{
public:
virtual ISplitter* CreateSplitter()=0;
virtual ~SplitterFactory(){}
};
//具體類
class BinarySplitter : public ISplitter{
};
class TxtSplitter: public ISplitter{
};
class PictureSplitter: public ISplitter{
};
class VideoSplitter: public ISplitter{
};
//具體工廠
class BinarySplitterFactory: public SplitterFactory{
public:
virtual ISplitter* CreateSplitter(){
return new BinarySplitter();
}
};
class TxtSplitterFactory: public SplitterFactory{
public:
virtual ISplitter* CreateSplitter(){
return new TxtSplitter();
}
};
class PictureSplitterFactory: public SplitterFactory{
public:
virtual ISplitter* CreateSplitter(){
return new PictureSplitter();
}
};
class VideoSplitterFactory: public SplitterFactory{
public:
virtual ISplitter* CreateSplitter(){
return new VideoSplitter();
}
};
//改良后mainform不依賴任何具體類。
//具體產生什么工廠mainform不負責，由別人傳入給它的參數來決定
class MainForm : public Form
{
SplitterFactory* factory;//工廠，工廠可以選擇
public:
MainForm(SplitterFactory* factory){
this->factory=factory;
}
void Button1_Click(){
ISplitter * splitter=
factory->CreateSplitter(); //多態new
splitter->split();
}
};
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原始程序
/*數據庫管理程序*/
class EmployeeDAO{
public:
vector<EmployeeDO> GetEmployees(){
SqlConnection* connection =
new SqlConnection();
connection->ConnectionString = "...";
SqlCommand* command =
new SqlCommand();
command->CommandText="...";
command->SetConnection(connection);
SqlDataReader* reader = command->ExecuteReader();
while (reader->Read()){
}
}
};
重構程序1
//數據庫訪問有關的基類
class IDBConnection{
};
class IDBConnectionFactory{
public:
virtual IDBConnection* CreateDBConnection()=0;
};
class IDBCommand{
};
class IDBCommandFactory{
public:
virtual IDBCommand* CreateDBCommand()=0;
};
class IDataReader{
};
class IDataReaderFactory{
public:
virtual IDataReader* CreateDataReader()=0;
};
//支持SQL Server
class SqlConnection: public IDBConnection{
};
class SqlConnectionFactory:public IDBConnectionFactory{
};
class SqlCommand: public IDBCommand{
};
class SqlCommandFactory:public IDBCommandFactory{
};
class SqlDataReader: public IDataReader{
};
class SqlDataReaderFactory:public IDataReaderFactory{
};
//支持Oracle
class OracleConnection: public IDBConnection{
};
class OracleCommand: public IDBCommand{
};
class OracleDataReader: public IDataReader{
};
class EmployeeDAO{
IDBConnectionFactory* dbConnectionFactory;//可能傳入SQL
IDBCommandFactory* dbCommandFactory;//可能傳入Oracle
IDataReaderFactory* dataReaderFactory;//它們三個必須是同一系列的。所有就有了abstract factory模式
//因此需要將這三個合成同一個工廠，以保證關聯性
public:
vector<EmployeeDO> GetEmployees(){
IDBConnection* connection =
dbConnectionFactory->CreateDBConnection();
connection->ConnectionString("...");
IDBCommand* command =
dbCommandFactory->CreateDBCommand();
command->CommandText("...");
command->SetConnection(connection); //關聯性
IDBDataReader* reader = command->ExecuteReader(); //關聯性
while (reader->Read()){
}
}
};
重構程序2
//數據庫訪問有關的基類
class IDBConnection{
};
class IDBCommand{
};
class IDataReader{
};
class IDBFactory{
public:
virtual IDBConnection* CreateDBConnection()=0;
virtual IDBCommand* CreateDBCommand()=0;
virtual IDataReader* CreateDataReader()=0;
};
//支持SQL Server
class SqlConnection: public IDBConnection{
};
class SqlCommand: public IDBCommand{
};
class SqlDataReader: public IDataReader{
};
class SqlDBFactory:public IDBFactory{
public:
virtual IDBConnection* CreateDBConnection();
virtual IDBCommand* CreateDBCommand();
virtual IDataReader* CreateDataReader();
};
//支持Oracle
class OracleConnection: public IDBConnection{
};
class OracleCommand: public IDBCommand{
};
class OracleDataReader: public IDataReader{
};
class EmployeeDAO{
IDBFactory* dbFactory;
public:
vector<EmployeeDO> GetEmployees(){
IDBConnection* connection =
dbFactory->CreateDBConnection();
connection->ConnectionString("...");
IDBCommand* command =
dbFactory->CreateDBCommand();
command->CommandText("...");
command->SetConnection(connection); //關聯性
IDBDataReader* reader = command->ExecuteReader(); //關聯性
while (reader->Read()){
}
}
};
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模型實現
/*文件分割程序*/
//抽象類
class ISplitter{
public:
virtual void split()=0;
virtual ISplitter* clone()=0; //通過克隆自己來創建對象
virtual ~ISplitter(){}
};
//具體類
class BinarySplitter : public ISplitter{
public:
virtual ISplitter* clone(){
return new BinarySplitter(*this);
}
};
class TxtSplitter: public ISplitter{
public:
virtual ISplitter* clone(){
return new TxtSplitter(*this);
}
};
class PictureSplitter: public ISplitter{
public:
virtual ISplitter* clone(){
return new PictureSplitter(*this);
}
};
class VideoSplitter: public ISplitter{
public:
virtual ISplitter* clone(){
return new VideoSplitter(*this);
}
};
//客戶端程序
class MainForm : public Form
{
ISplitter* prototype;//原型對象
public:
MainForm(ISplitter* prototype){ //通過向MainForm傳遞具體類來創建具體類
this->prototype=prototype;
}
void Button1_Click(){
ISplitter * splitter=
prototype->clone(); //克隆原型
splitter->split();
}
};
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模型實現
//類似模板模式
class House{
//....
};
class HouseBuilder {
public:
House* GetResult(){
return pHouse;
}
virtual ~HouseBuilder(){}
protected:
House* pHouse;
virtual void BuildPart1()=0;
virtual void BuildPart2()=0;
virtual void BuildPart3()=0;
virtual void BuildPart4()=0;
virtual void BuildPart5()=0;
};
class StoneHouse: public House{
};
class StoneHouseBuilder: public HouseBuilder{
protected:
virtual void BuildPart1(){
//pHouse->Part1 = ...;
}
virtual void BuildPart2(){
}
virtual void BuildPart3(){
}
virtual void BuildPart4(){
}
virtual void BuildPart5(){
}
};
class HouseDirector{
public:
HouseBuilder* pHouseBuilder;
HouseDirector(HouseBuilder* pHouseBuilder){
this->pHouseBuilder=pHouseBuilder;
}
House* Construct(){
pHouseBuilder->BuildPart1();
for (int i = 0; i < 4; i++){
pHouseBuilder->BuildPart2();
}
bool flag=pHouseBuilder->BuildPart3();
if(flag){
pHouseBuilder->BuildPart4();
}
pHouseBuilder->BuildPart5();
return pHouseBuilder->GetResult();
}
};
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Facade 門面模式
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Proxy 代理模式
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原始程序
class ISubject{
public:
virtual void process();
};
class RealSubject: public ISubject{
public:
virtual void process(){
//....
}
};
class ClientApp{
ISubject* subject;
public:
ClientApp(){
subject=new RealSubject();
}
void DoTask(){
//...
subject->process();
//....
}
};
重構程序
class ISubject{
public:
virtual void process();
};
//Proxy的設計
class SubjectProxy: public ISubject{
public:
virtual void process(){
//對RealSubject的一種間接訪問
//....
}
};
class ClientApp{
ISubject* subject;
public:
ClientApp(){
subject=new SubjectProxy();
}
void DoTask(){
//...
subject->process();
//....
}
};
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Adapter適配器
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模式實例
//目標接口（新接口）
class ITarget{
public:
virtual void process()=0;
};
//遺留接口（老接口）
class IAdaptee{
public:
virtual void foo(int data)=0;
virtual int bar()=0;
};
//遺留類型
class OldClass: public IAdaptee{
//....
};
//對象適配器
class Adapter: public ITarget{ //繼承
protected:
IAdaptee* pAdaptee;//組合
public:
Adapter(IAdaptee* pAdaptee){
this->pAdaptee=pAdaptee;
}
virtual void process(){
int data=pAdaptee->bar();
pAdaptee->foo(data);
}
};
//類適配器
class Adapter: public ITarget,
protected OldClass{ //多繼承
}
int main(){
IAdaptee* pAdaptee=new OldClass();
ITarget* pTarget=new Adapter(pAdaptee);
pTarget->process();
}
class stack{
deqeue container;
};
class queue{
deqeue container;
};
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Mediator 中介者
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