QtQuick一分钟技巧:使用C++保存全局数据

#ifndef QMLGLOBALDATA_H
#define QMLGLOBALDATA_H

#include <QObject>
#include<map>
#include<QVariant>
using namespace  std;
class QmlGlobalData : public QObject
{
Q_OBJECT
public:

explicit QmlGlobalData(QObject *parent = 0);
Q_INVOKABLE  void _set(QString name,QVariant  d)
{
datas[name] = d;
}

Q_INVOKABLE  QVariant _get(QString name)
{
if(datas[name]!=NULL)
{
return datas[name];
}
//如果不存在字段 返回 undefined
return QVariant("");
}

signals:

public slots:
private:
std::map<QString,QVariant>  datas;
};

#endif // QMLGLOBALDATA_H

Component.onCompleted: {
Global._set("width",100)
Global._set("height",80)
Global._set("title","Hello")
console.log(Global._get("width"))
console.log(Global._get("height"))
console.log(Global._get("title"))
console.log(Global._get("xxx"))//尝试获取一个不存在的数据
}

打印
qml: 100
qml: 80
qml: Hello
qml: undefined