Qt实现全局观察者模式（多层窗体之间直接传递消息）-支持传参
主要参考文章为：Qt实现全局观察者模式（多层窗体之间直接传递消息）-支持传参
内容为：
globalObserver.h
#ifndef GLOBALOBSERVER_H
#define GLOBALOBSERVER_H
#include <QObject>
#include "obesrverApater.h"
struct relationData
{
QString type;
QObject *reciver;
obesrverApater *obesrverApater;
};
class globalObserver : public QObject
{
Q_OBJECT
public:
//因为是全局只有一个，所以直接单例模式
static globalObserver* getGlobalObserver();
static void release();
static globalObserver *m_pInst;
//绑定
void attach(const QString type, QObject *reciver, const char *method);
//解绑
void detach(const QString type, const QObject* reciver);
//触发
void notify(const QString type);
private:
explicit globalObserver(QObject *parent = 0);
~globalObserver();
private:
QList<relationData*> m_oRelationList;
};
#endif // GLOBALOBSERVER_H
relationData：结构体，保存对应关系； relationData::type：字符串类型，就相当于信号的唯一标识符 relationData::reciver：信号接收者，保存这个变量主要实在detach的时候去使用。 relationData::obesrverApater;这个类的作用就很重要了，具体看该类的详解。
obesrverApater.h
#ifndef OBESRVERAPATER_H
#define OBESRVERAPATER_H
#include <QObject>
class obesrverApater;
//工厂，方便构造对象
class obesrverApaterFactory
{
public:
static obesrverApaterFactory *getInst();
static void realese();
static obesrverApaterFactory* inst;
obesrverApater* createObesrverApater();
private:
obesrverApaterFactory()
{}
};
//中间层，用来连接信号槽
class obesrverApater : public QObject
{
Q_OBJECT
public:
explicit obesrverApater(QObject *parent = 0);
signals:
void notify();
};
#endif // OBESRVERAPATER_H
obesrverApater：该类的主要目的是attach的时候，将传进来的槽函数直接绑定到改类的notify信号，因为传进来的槽函数，要想在触发时去掉用拿不到函数名称，所以借助中间层直接绑定，在触发的时候直接去触发中间层的信号，就可达到目的。
obesrverApaterFactory：创建中间层的工厂，方便类创建。
接下来就主要看看具体函数的实现了：
工厂类去创建中间层对象实体 obesrverApater *obesrverApaterFactory::createObesrverApater() { return new obesrverApater(); }
观察者绑定函数实现
void globalObserver::attach(const QString type, QObject *reciver, const char *method)
{
obesrverApater *oA = obesrverApaterFactory::getInst()->createObesrverApater();
connect(oA, SIGNAL(notify()), reciver, method);
relationData *data = new relationData();
data->type = type;
data->reciver = reciver;
data->obesrverApater = oA;
m_oRelationList.append(data);
}
观察者解绑函数实现
void globalObserver::detach(const QString type, const QObject *reciver)
{
QList<relationData*>::iterator iter = m_oRelationList.begin();
while (iter != m_oRelationList.end())
{
if ((*iter)->type.compare(type) == 0 && (*iter)->reciver == reciver)
{
relationData *data = *iter;
m_oRelationList.removeOne((*iter));
delete data->obesrverApater;
delete data;
return;
}
iter++;
}
}
观察者触发函数实现
void globalObserver::notify(const QString type)
{
QList<relationData*>::iterator iter = m_oRelationList.begin();
while (iter != m_oRelationList.end())
{
if ((*iter)->type.compare(type) == 0)
{
emit (*iter)->obesrverApater->notify();
}
iter++;
}
}
程序结束时别忘了销毁
globalObserver::~globalObserver()
{
//释放列表数据
QList<relationData*>::iterator iter = m_oRelationList.begin();
while (iter != m_oRelationList.end())
{
delete (*iter)->obesrverApater;
delete *iter;
iter++;
}
}
测试：
测试代码
Widget::Widget(QWidget *parent)
: QWidget(parent)
{
globalObserver::getGlobalObserver()->attach("haha", this, SLOT(haha()));
globalObserver::getGlobalObserver()->attach("hehe", this, SLOT(hehe()));
QPushButton *p = new QPushButton("haha", this);
connect(p, SIGNAL(clicked()), this, SLOT(onHaha()));
p->setGeometry(10, 10, 200, 40);
}
Widget::~Widget()
{
globalObserver::getGlobalObserver()->detach("haha", this);
globalObserver::getGlobalObserver()->detach("hehe", this);
}
void Widget::haha()
{
QMessageBox::about(this, "", "haha");
}
void Widget::hehe()
{
QMessageBox::about(this, "", "hehe");
}
void Widget::onHaha()
{
globalObserver::getGlobalObserver()->notify("haha");
}