QT共享内存QSharedMemory读写例子

#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); this->setWindowTitle(QStringLiteral("QT共享内存")); } MainWindow::~MainWindow() { delete ui; } void MainWindow::readmemdata() { QSharedMemory sha; sha.setNativeKey(mapNmae); if (!sha.attach()) { ui->textBrowser->setText(tr("Unable to attach to shared memory segment.\n" \ "Load an image first.")); return; } QByteArray ba; sha.lock(); ba=(char*)sha.constData(); ui->textBrowser->setText(QString(ba.data())); sha.unlock(); sha.detach(); } void MainWindow::writememdata(QByteArray ba) { sharedMemory.setNativeKey(mapNmae); int size = ba.size(); //6.判断sharedMemory是否已经创建 if(!sharedMemory.create(4*1024)){ qDebug()<<(tr("Unable to create memory segment."))<< sharedMemory.errorString(); }else{ sharedMemory.lock(); char *to = (char*)sharedMemory.data(); const char *from = ba.data(); memcpy(to, from, qMin(sharedMemory.size(), size)); sharedMemory.unlock(); qDebug()<<"shared memory has created"; } } void MainWindow::on_read_button_clicked() { readmemdata(); } void MainWindow::on_pushButton_2_clicked() { QByteArray ba = ui->textEdit->toPlainText().toLocal8Bit(); writememdata(ba); }