Qsettings只能存储一次？

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字段。这意味着只有当我在第二轮中应用相同的逻辑时它才起作用。

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 

的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

最有可能是因为你LEA国王QSettings'内存和资源在你的函数，所以第一次调用使后来的失败，因为占用的文件句柄，或什么东西。