Qsettings 只能存储一次值吗？

Question

我正在使用 Qsetting 来存储上次使用的值。我的代码只适用于一个领域。这意味着当我在第二轮应用相同的逻辑时它只工作一次它不会那样做。

fileio.cpp

#include "fileio.h"
#include <QSettings>
#include <QStandardPaths>
#include <QtAndroid>
#include <QtAndroidExtras/QAndroidJniObject>
#include <QAndroidJniEnvironment>
#include <QtGui>
#include <QDebug>

FileIo::FileIo(QObject *parent)
    : QObject(parent)
{
    connect(this, SIGNAL(maxrpmChanged()), this, SLOT(writeSettings()));
    connect(this, SIGNAL(rampupChanged()), this, SLOT(writeSettings()));
}
//for Maxrpm
void FileIo::setMaxrpm(const QString &a) {
    if (a != m_maxrpm) {
        m_maxrpm = a;
        emit maxrpmChanged();
    }
}
QString FileIo::getMaxrpm() const {return m_maxrpm;}

//for Filename
void FileIo::setFilename(const QString &a) {

    if (a != m_filename) {
        m_filename = a;
        emit filenameChanged();
    }
}
QString FileIo::getFilename() const {return m_filename;}

//for Rampup
void FileIo::setRampup(const QString &a) {
    if (a != m_rampup) {
        m_rampup = a;
        emit rampupChanged();
    }
}
QString FileIo::getRampup() const {return m_rampup;}



void FileIo::readSettings(const QString &temp)
{
    QString m_path ;
    QString m_filename;
    QSettings * p_settings;
    QSettings settings("BlueSparq","motorapp");
    m_path = QStandardPaths::writableLocation(QStandardPaths::ConfigLocation) ;
    m_filename = temp ;
    p_settings = new QSettings(m_path + "/"+ m_filename,QSettings::IniFormat) ;
    setMaxrpm(p_settings->value("target_RPM",QString("900")).toString());
    qDebug() <<m_maxrpm;
    //for Rampup
    setRampup(p_settings->value("rampup","250").toString());
    qDebug() <<m_rampup;
}

void FileIo::writeSettings()
{
    QString m_path ;
    QSettings * p_settings;
    QSettings settings("BlueSparq","motorapp");
    m_path = QStandardPaths::writableLocation(QStandardPaths::ConfigLocation) ;
    p_settings = new QSettings(m_path + "/"+ m_filename,QSettings::IniFormat) ;
    p_settings->setValue("target_RPM",m_maxrpm);
    qDebug() << m_rampup;
    p_settings->setValue("rampup",m_rampup);
    qDebug() << m_rampup;
    p_settings->sync();
}

fileio.h

#ifndef FILEIO_H
#define FILEIO_H
#include <QObject>

class FileIo : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString maxrpm READ getMaxrpm WRITE setMaxrpm NOTIFY maxrpmChanged)
    Q_PROPERTY(QString filename READ getFilename WRITE setFilename NOTIFY filenameChanged)
    Q_PROPERTY(QString rampup READ getRampup WRITE setRampup NOTIFY rampupChanged)
public:
    explicit FileIo(QObject *parent = 0);

    //For MaxRPM
    void setMaxrpm(const QString &a);
    QString getMaxrpm() const;

    //For Filename
    void setFilename(const QString &a);
    QString getFilename() const;

    //For Ramup
    void setRampup(const QString &a);
    QString getRampup() const;

    Q_INVOKABLE void writeSettings();
    Q_INVOKABLE void readSettings(const QString &temp);

signals:
    void maxrpmChanged();
    void filenameChanged();
    void rampupChanged();



public slots:


private slots:


private:
    QString m_maxrpm;
    QString m_filename;
    QString m_rampup;

};


#endif // FILEIO_H

main.cpp

#include <QtGui>
#include <QtQuick>
#include "sertransclient.h"
#include "fileio.h"
QObject *object;

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    //added now
    QQuickView view;

    QObject::connect((QObject*)view.engine(), SIGNAL(quit()), &app, SLOT(quit()));

    qRegisterMetaType<SerTransClient::BaudRate>("SerTransClient::BaudRate");
    qRegisterMetaType<SerTransClient::DataBits>("SerTransClient::DataBits");
    qRegisterMetaType<SerTransClient::Parity>("SerTransClient::Parity");
    qRegisterMetaType<SerTransClient::StopBits>("SerTransClient::StopBits");
    qRegisterMetaType<SerTransClient::FlowControl>("SerTransClient::FlowControl");
    qmlRegisterType<SerTransClient>("sertransclient", 1, 0, "SerTransClient");
    qmlRegisterType<FileIo>("fileIo", 1, 0, "FileIo");
    view.setResizeMode(QQuickView::SizeRootObjectToView);
    view.setSource(QUrl(QStringLiteral("qrc:/main.qml")));
    view.show();
    object = view.rootObject();
    //



    return app.exec();
}

Answer 1

很可能是因为您在函数中泄漏了 QSettings' 内存 和资源 ，所以第一次调用导致后面的调用失败，因为占用了文件句柄, 或东西。

Qsettings 只能存储一次值吗？

Qsettings able to store value only once?

c++

qml

qsettings