QT实现预编译的浏览器插件 JS与QT对象进行交互

JS与QT对象进行交互，顾名思义，就是将QT对象和JS对象相关联，然后JS可以调用QT对象的方法并返回值，反之QT可以调用JS的方法（回调）。

1，把QT对象加入到JS中，并实现JS调用QT对象。

// 实现一个新类
class QFoo : public QObject
{
Q_OBJECT
public:
QFoo(QObject *parent) {}
void initialize(QWebView *wv);

public slots:
void print(const QString &msg);

private slots:
void addObject();

private:
QWebFrame *wf;
};

void QFoo::initialize(QWebView *wv)
{
wf = wv->page()->mainFrame();
// Add to the javascript window object
addObject();
// connect the signal for javascript window object cleared, which happened
// at page switching etc.
connect(wf, SIGNAL(javaScriptWindowObjectCleared()), this, SLOT(addObject()));
}

void QFoo::addObject()
{
wf->addToJavaScriptWindowObject(QString("QFoo"), this);
}

void QFoo::print(const QString &msg)
{
qDebug() << "Output the message " << msg;
}

测试主函数  

int main(int argc, char *argv[])
{
QApplication test(argc, argv);

QWebView *wv = new QWebView();

QFoo *foo = new QFoo(wv);
foo->initialize(wv);

wv->setUrl(QUrl("foo.html"));
wv->show();

return test.exec();
}

HTML测试代码：

<script>
QFoo.print("Hello world!");
</script>

/*****************************************************************/

2，通过将本地QT的信号和JS的槽连接起来的方式，实现QT对象调用JS（回调）

//定义QT对象
class WebApp : public QObject
{
Q_OBJECT
public:
WebApp(QObject *parent){}
void initialize(QWebView *wv);

signals: //定义QT信号
void launchSignal(QString obj);
void getAppListSignal(QString obj);

public slots:
void launch(const QString &appName);
void getAppList();

private slots:
void addObject();

private:
QWebFrame *wf;
};

//QT对象如何发射信号
void WebApp::launch(const QString &appName)
{
QString url = "";
if(appName == "EManual"){
url = "{\"ip\":\"192.168.42.129\",\"port\":\"12100\"}";
}else if(appName == "DBA"){
url = "{\"ip\":\"192.168.42.129\",\"port\":\"12102\"}";
}

/* send signal */
emit launchSignal(url);
}

HTML测试代码

<script>
webapp.launchSignal.connect(launchCallBack);
webapp.launch("EManual");

function launchCallBack(object)
{
var msg = JSON.parse(object);
var url = "http://" + msg.ip + "/" + msg.port;
window.location.href = url;
}
</script>

3，实现JS对象调用QT 返回的为JS对象而不是JSON串

//定义QT对象
class WebApp : public QObject
{
Q_OBJECT
public:
WebApp(QObject *parent){}
void initialize(QWebView *wv);

public slots:
//定义槽函数，其可以返回和接受JS对象
QMap<QString, QVariant> slotThatReturns(const QMap<QString,QVariant>& object);

private slots:
void addObject();

private:
QWebFrame *wf;
//返回的JS对象
QMap<QString, QVariant> m_returnObject;
};

//返回对象
QMap<QString, QVariant> WebApp::slotThatReturns(const QMap<QString,QVariant>& object)
{
qDebug() << "SampleQObject::slotThatReturns";
this->m_returnObject.clear();
this->m_returnObject.unite(object);
QString addedBonus = QString::number(object["intValue"].toInt(),
10).append(" added bonus.");
this->m_returnObject["stringValue"] = QVariant(addedBonus);
qDebug() << "SampleQObject::slotThatReturns" << this->m_returnObject;
return this->m_returnObject; // 返回m_returnObject包含有字符串 1 added bonus
}

HTML测试代码

<script>
var object = {intValue: 1};
var returnedObject = webapp.slotThatReturns(object);
alert(returnedObject.stringValue);
</script>

/*****************************************************************/

4，另一种方式实现QT对象调用JS对象（回调）

//定义QT对象
class WebApp : public QObject
{
Q_OBJECT
public:
WebApp(QObject *parent){}
void initialize(QWebView *wv);

public slots:
//定义槽函数，其可以返回和接受JS对象
void getAsynCallBack(const QString &type,const QString &success,const QString $error);

private slots:
void addObject();

private:
QWebFrame *wf;
};

//函数实现
void Vehicle::getAsynCallBack(const QString &type,const QString &success,const QString $error)
{
QString msg = "";
//此处省略n行

if(error)
{
qDebug() << "error! " << msg;
msg = "{\"status\":\"error\",\"errorid\":\"-1\"}";
wf->evaluateJavaScript("error('" + msg + "')");
}
else
{
qDebug() << "error! " << msg;
msg  = "{\"status\":\"ok\"}";
wf->evaluateJavaScript("success('" + msg + "')");
}
}

HTML测试代码

<script>
vehicle.getAsynCallBack("vehicle_info_fuel_type",success,error);

function success(data){
alert(data);
}

function error(data){
alert(data);
}
</script>

参考文档：
http://www.cnblogs.com/ziqiuqiandao/archive/2012/12/29/2838652.html http://blog.csdn.net/myaccella/article/details/6956534 http://software.intel.com/zh-cn/blogs/2010/06/09/qt-webkitqobjectjavascript/