Question

我正在撰写一个节目,在QSettings物体中储存所有环境。现在我要让用户选择改变其数据储存地点。申请资格并不能改变其范围,将其全部数据复制到一个新的地点,从登记处到档案中所占百分比是APPDATA%。

我知道:

QSettings::setPath() is used before construction and doesn t affect existing objects.
The copy operator is private. I could subclass QSettings but I am afraid of settings being lost during the copy operation because of other threads writing simultaneously.

我如何把我的节目环境移至一个新的地点? 如果有可能,我真的希望能以重新安置的方式做到这一点。

Answer 1

read-安全单带包装类别是否是一种选择?

class Settings {

public:
    static Settings& instance() 
    { 
        static Settings* inst = 0;
        if (!inst)
            inst = new Settings();
        return *inst; 
    }
    QSettings& getSettings { QMutexLocker(&m_mutex); return *m_settings; }
    bool migrateLocation(...) 
    { 
        QMutexLocker(&m_mutex); 
        QSettings* newSettings = new QSettings(...new parameters...);
        //... copy over the stuff
        delete m_settings;
        m_settings = newSettings;
    }
private:
    Settings() { m_settings = new QSettings(...); }

    static QMutex m_mutex;
    QSettings* m_settings;
}

友情链接