用单体类型注册单体对象到qml中

一个单体对象不需要用户手动构造实例就可以将属性，信号，方法在命名空间里暴露。QObject
单体类型是非常有效和安全的方式提供函数和全局属性值。单体对象不能和QQmlContext联合访问引擎的内容。单体对象有QQmlEngine构造，随着QQmlEngine销毁而随之销毁。

1、QJSValue 注册一个Value属性

static QJSValue getCountStatic(QQmlEngine* engine,QJSEngine* scriptEngine){
Q_UNUSED(engine);
static int seedValue = 5;
QJSValue example = scriptEngine->newObject();
example.setProperty("someProperty",++seedValue);
return example;
}

注册：

qmlRegisterSingletonType("Qt.example.signle",1,0,"MyApi",getCountStatic);

//脚本中使用

property var somebee:ExampleSingle.MyApi.someProperty

2、QObject*

class SingleObject : public QObject
{
Q_OBJECT
Q_PROPERTY(int someindex READ someindex WRITE setSomeIndex NOTIFY indexChange)
public:
SingleObject(QObject* parent = 0);
~SingleObject();
int someindex() const;
void setSomeIndex(int index);

Q_INVOKABLE int doSomething();

signals:
void indexChange(int index);
protected:

private:
int m_someindex;
};

使用Q_INVOKABLE注册

static QObject* getQtObject(QQmlEngine* engine,QJSEngine* scriptEngine){
Q_UNUSED(engine);
Q_UNUSED(scriptEngine);
SingleObject* obj = new SingleObject;
return obj;
}

注册：qmlRegisterSingletonType<SingleObject>("Qt.example.signle",1,0,"MyQtApi",getQtObject);

脚本调用：

import MessagePerson 1.0
import Qt.example.signle 1.0 as ExampleSingle
Message{
author:"王bull"
authorDate:new Date()
property var somebee:ExampleSingle.MyApi.somePropertyproperty var qtbee:ExampleSingle.MyQtApi.doSomething()
}

直接上代码了，会使用即可，C++单体在脚本中的调用介绍到这里了。