使用 qsettings 保存和加载修改

Question

我有 2 windows ( window 1 ) & ( window 2 ) : 看图片。 -在 window 1 上有一个 "edit" 按钮应该打开 window 2（并加载保存在 window 2 上的修改） -On window 2，我有 96 个按钮，最初是绿色的，如果我点击其中一个按钮，它就会变成红色。我的 "OK" 按钮应该关闭 window 2 并保存修改（红色按钮）。如果我通过单击 window 1 的 "edit" 按钮重新打开 window 2，最后一步的红色按钮应该保持红色并且变得不可选中。我如何使用 QSettings 做到这一点？这是我的 savesettings 方法代码：（我不知道它是否正确但我认为是的！）

void Vessels::SaveSettings()
{
        QSettings setting("My_vessels","My_selected_vessels");
        setting.beginGroup("Vessels");
        if (ui->pushButton_4->isChecked()){
        ui->pushButton_4->setCheckable(false);}
        setting.setValue("selected",ui->pushButton_4->isCheckable());
        setting.endGroup();
}

我面临两个问题： 1) 保存和加载按钮（在本例中分别为 "OK" 和 "Edit"）不是来自同一个 window。 2) 我不知道如何实现应该附加到 "Edit" 按钮的 loadSettings 方法。

Answer 1

首先，尝试检查您的注册表以检查您是否正确保存了这些值。

关于load函数，你可以这样用：

QSettings settings("My_vessels","My_selected_vessels");
settings.beginGroup("Vessels");
checked = settings.value("selected").toBool();
settings.endGroup();

对不起，我不知道你所有的变量名。但是，这与我从 QSettings 加载内容的函数的格式相同。

希望对您有所帮助。

Answer 2

这是你的解决方案，正如我想出的，请在你这边测试，它对我有用：

文件：QSettings2.pro

#-------------------------------------------------
#
# Project created by QtCreator 2020-01-23T19:21:17
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QSettings2
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += \
        dialog.cpp \
        main.cpp \
        mainwindow.cpp

HEADERS += \
        dialog.h \
        mainwindow.h

FORMS += \
        dialog.ui \
        mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

文件：dialog.h

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

class QLabel;
class QSettings;
namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    Dialog(QSettings *settings, QWidget *parent = nullptr);
    ~Dialog();

private slots:
    void on_pushButtonOK_clicked();
    void on_pushButtonCancel_clicked();

private:
    QLabel* CreateNewLabel(QString text, QWidget* parent);
    void saveSettings();
    void loadSettings();
    Ui::Dialog *ui;
    QSettings *m_settings;
    const int ROWS = 8, COLS = 12;
};

#endif // DIALOG_H

文件：mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class QSettings;
namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_pushButton_clicked();

private:
    Ui::MainWindow *ui;
    QSettings* m_settings;
};

#endif // MAINWINDOW_H

文件：dialog.cpp

#include "dialog.h"
#include "ui_dialog.h"
#include <QGridLayout>
#include <QDebug>
#include <QSettings>

Dialog::Dialog(QSettings *settings, QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog),
    m_settings(settings)
{
    ui->setupUi(this);
    ui->frame->setStyleSheet(QString());//we did draw border just for design time view
    ui->pushButton_Circular->hide();

    QGridLayout *gridLayout = new QGridLayout();

    //gridLayout->setColumnStretch(0, 1);
    //gridLayout->setRowStretch(0, 1);

    for(int i = 1; i <= COLS; i++)
    {
        //gridLayout->setColumnStretch(i, 1);
        QLabel *label = CreateNewLabel(QString::number(i), this);
        gridLayout->addWidget(label, 0, i);
    }

    for(int i = 1; i <= ROWS; i++)
    {
        //gridLayout->setRowStretch(i, 1);
        QLabel *label = CreateNewLabel(QString("%1").arg(static_cast<char>('A' + i -1)), this);
        gridLayout->addWidget(label, i, 0);
    }

    QString buttonIdText;
    for(int i = 1; i <= ROWS; i++)
    {
        for(int j = 1; j<= COLS; j++)
        {
            QPushButton *button = new QPushButton(this);
            button->setMaximumSize(40, 40);
            button->setMinimumSize(40, 40);
            button->setStyleSheet(ui->pushButton_Circular->styleSheet());
            button->setCheckable(true);

            buttonIdText = QString::number((i-1)*COLS + j);
            button->setText(buttonIdText);
            button->setObjectName("GridButton_" + buttonIdText);

            gridLayout->addWidget(button, i, j);
        }
    }

    ui->frame->setLayout(gridLayout);
    loadSettings();
}

Dialog::~Dialog()
{
    delete ui;
}

QLabel *Dialog::CreateNewLabel(QString text, QWidget *parent)
{
    QLabel *label = new QLabel(text, parent);
    label->setFont(QFont(label->font().family(), 10, 500));
    label->setAlignment(Qt::AlignCenter);
    label->setStyleSheet("background-color: rgb(170, 0, 0);");
    label->setMaximumSize(40, 40);
    label->setMinimumSize(40, 40);
    return label;
}

void Dialog::saveSettings()
{
    QString key;
    QVariant value;
    m_settings->beginGroup("GridButtonsStatus");
    foreach(QObject *childObject, ui->frame->children())
    {
        if(QPushButton *button = qobject_cast<QPushButton*>(childObject))
        {
            key = button->objectName();
            value = button->isChecked();
            m_settings->setValue(key, value);
        }
    }
    m_settings->endGroup();
    m_settings->sync();
}

void Dialog::loadSettings()
{
    QString key;
    m_settings->beginGroup("GridButtonsStatus");
    for(int i = 1; i <= ROWS * COLS; i++)
    {
        key = QString("GridButton_%1").arg(i);
        qDebug() << "--- key = " << key <<", value = " <<  m_settings->value(key) << endl;
        QPushButton *button = ui->frame->findChild<QPushButton*>(key); //key was push button object name
        if(button)
        {
            bool is_Checked = m_settings->value(key, false).toBool();
            button->setChecked(is_Checked);
            button->setEnabled(!is_Checked);
        }
    }
    m_settings->endGroup();
}

void Dialog::on_pushButtonOK_clicked()
{
    saveSettings();
    close();
}

void Dialog::on_pushButtonCancel_clicked()
{
    close();
}

文件：main.cpp

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

文件：mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "dialog.h"

#include <QSettings>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow), m_settings(new QSettings(qAppName() + ".ini", QSettings::IniFormat))
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}
#include <QDebug>
void MainWindow::on_pushButton_clicked()
{
    Dialog dialog(m_settings);
    dialog.exec();
}

文件：dialog.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Dialog</class>
 <widget class="QDialog" name="Dialog">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>730</width>
    <height>501</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Dialog</string>
  </property>
  <widget class="QLabel" name="label">
   <property name="geometry">
    <rect>
     <x>50</x>
     <y>10</y>
     <width>331</width>
     <height>31</height>
    </rect>
   </property>
   <property name="font">
    <font>
     <pointsize>14</pointsize>
     <weight>75</weight>
     <bold>true</bold>
    </font>
   </property>
   <property name="text">
    <string>Choose your vessels:</string>
   </property>
  </widget>
  <widget class="QPushButton" name="pushButtonOK">
   <property name="geometry">
    <rect>
     <x>560</x>
     <y>440</y>
     <width>160</width>
     <height>41</height>
    </rect>
   </property>
   <property name="text">
    <string>OK</string>
   </property>
  </widget>
  <widget class="QPushButton" name="pushButton_Circular">
   <property name="geometry">
    <rect>
     <x>20</x>
     <y>440</y>
     <width>40</width>
     <height>40</height>
    </rect>
   </property>
   <property name="styleSheet">
    <string notr="true">QPushButton {
    border-radius: 20px;
    border-style: outset;
    background: qradialgradient(
        cx: 0.3, cy: -0.4, fx: 0.3, fy: -0.4,
        radius: 1.35, stop: 0 green, stop: 1 #009900
        );
    padding: 5px;
    }

QPushButton:hover {
    background: qradialgradient(
        cx: 0.3, cy: -0.4, fx: 0.3, fy: -0.4,
         radius: 1.35, stop: 0 red, stop: 1 #004400
        );
    }

QPushButton:checked {
    border-style: inset;
    background: qradialgradient(
        cx: 0.4, cy: -0.1, fx: 0.4, fy: -0.1,
        radius: 1.35, stop: 0 red, stop: 1 #990000
        );
    }
</string>
   </property>
   <property name="text">
    <string/>
   </property>
   <property name="checkable">
    <bool>true</bool>
   </property>
   <property name="checked">
    <bool>false</bool>
   </property>
  </widget>
  <widget class="QFrame" name="frame">
   <property name="geometry">
    <rect>
     <x>20</x>
     <y>50</y>
     <width>520</width>
     <height>360</height>
    </rect>
   </property>
   <property name="sizePolicy">
    <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
     <horstretch>0</horstretch>
     <verstretch>0</verstretch>
    </sizepolicy>
   </property>
   <property name="minimumSize">
    <size>
     <width>520</width>
     <height>360</height>
    </size>
   </property>
   <property name="maximumSize">
    <size>
     <width>520</width>
     <height>360</height>
    </size>
   </property>
   <property name="styleSheet">
    <string notr="true">border:1px solid red</string>
   </property>
   <property name="frameShape">
    <enum>QFrame::StyledPanel</enum>
   </property>
   <property name="frameShadow">
    <enum>QFrame::Raised</enum>
   </property>
  </widget>
  <widget class="QPushButton" name="pushButtonCancel">
   <property name="geometry">
    <rect>
     <x>370</x>
     <y>440</y>
     <width>160</width>
     <height>41</height>
    </rect>
   </property>
   <property name="text">
    <string>CANCEL</string>
   </property>
  </widget>
  <zorder>frame</zorder>
  <zorder>label</zorder>
  <zorder>pushButtonOK</zorder>
  <zorder>pushButton_Circular</zorder>
  <zorder>pushButtonCancel</zorder>
 </widget>
 <resources/>
 <connections/>
</ui>

文件：mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>573</width>
    <height>374</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QLabel" name="label">
    <property name="geometry">
     <rect>
      <x>40</x>
      <y>20</y>
      <width>271</width>
      <height>81</height>
     </rect>
    </property>
    <property name="font">
     <font>
      <pointsize>14</pointsize>
      <weight>75</weight>
      <bold>true</bold>
     </font>
    </property>
    <property name="text">
     <string>Prepare YourSolutions</string>
    </property>
   </widget>
   <widget class="QLabel" name="label_2">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>150</y>
      <width>91</width>
      <height>31</height>
     </rect>
    </property>
    <property name="font">
     <font>
      <pointsize>9</pointsize>
     </font>
    </property>
    <property name="text">
     <string>Solution 1</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>154</x>
      <y>152</y>
      <width>101</width>
      <height>31</height>
     </rect>
    </property>
    <property name="text">
     <string>Edit</string>
    </property>
   </widget>
  </widget>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>

使用 qsettings 保存和加载修改

save and load modifications with qsettings

c++

qt

qsettings

c++11

qpushbutton