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Qt5 读写共享内存,已验证,支持汉字的正确写入和读取

Qt5,读写共享内存,Windows下同一个进程下可测试;

通过查看控制台输出即可看到写入和读出的内容;

相比网上其他介绍的方法,大部分均不支持汉字的正常读取,下面方法已经做了汉字存储的支持,可以进行测试;

  #include <QSharedMemory> //头文件引入
  #include <QDateTime>

  //声明变量
  QSharedMemory wrire_sharedMemory;
  QSharedMemory read_sharedMemory;

内存:

void MainWindow::writeShareMemory(const QString _key ,const QString _value){
    qDebug() << __PRETTY_FUNCTION__ << ":_key" << _key << " ;_value:" << _value;

    wrire_sharedMemory.setKey(_key);
    if(wrire_sharedMemory.isAttached())
    {
        //将该进程与共享内存段分离
        wrire_sharedMemory.detach();
    }

    if (!wrire_sharedMemory.create(1024)) {
        qDebug() << __PRETTY_FUNCTION__ << "Cannot create shared memory.";
        return ;
    }

    QBuffer buffer;
    buffer.open(QBuffer::ReadWrite);
    QDataStream out(&buffer);
    out << _value;
    int size = buffer.size();

    wrire_sharedMemory.lock();

    char *to = (char*)wrire_sharedMemory.data();
    const char *from = buffer.data().data();
    memcpy(to,from, qMin(wrire_sharedMemory.size(), size));
    wrire_sharedMemory.unlock();
}

内存:

void MainWindow::readShareMemory(const QString _key ,QString &msg){
    qDebug() << __PRETTY_FUNCTION__ << ":_key:" << _key;
    read_sharedMemory.setKey(_key);

    // 尝试附加到共享内存
    if (!read_sharedMemory.attach(QSharedMemory::ReadOnly)) {
        qDebug() << __PRETTY_FUNCTION__ << "无法附加到共享内存区域。";
        return ;
    }

    QBuffer buffer;
    QDataStream in(&buffer);
    read_sharedMemory.lock();

    buffer.setData((char*)read_sharedMemory.constData(), read_sharedMemory.size());
    buffer.open(QBuffer::ReadOnly);
    in >> msg;
    
    qDebug() << __PRETTY_FUNCTION__ << " 方法内,从共享内存读取的数据:" << msg;

    read_sharedMemory.unlock(); // 锁定共享内存
    read_sharedMemory.detach();
}

测试代码:

下面方法通过添加按钮事件触发即可测试

//测试写
QDateTime currentTime = QDateTime::currentDateTime();
QString currentTimeString = currentTime.toString("测试代码,yyyy-MM-dd_hh:mm:ss");
writeShareMemory("key666" ,currentTimeString);
//测试读
QString msg = "";
readShareMemory("key666" ,msg);
qDebug() << "函数返回,从共享内存读取的数据msg:" << msg;

;