博客
关于我
Qt 进程通信QSharedMemory
阅读量:370 次
发布时间:2019-03-05

本文共 2352 字,大约阅读时间需要 7 分钟。

学习了Qt中进程通信的一种QSharedMemory

一下是测试代码,运行两个即可,一个load一个push

 
dialog.h#ifndef DIALOG_H#define DIALOG_H#include 
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace Ui {class Dialog;}class Dialog : public QDialog{ Q_OBJECTpublic: explicit Dialog(QWidget *parent = 0); ~Dialog();private slots: void loadFromFileSlots(); void loadFromMemorySlots();private:// void detach();private: Ui::Dialog *ui; QSharedMemory *shareMemory;};#endif // DIALOG_Hdialog.cpp#include "dialog.h"#include "ui_dialog.h"Dialog::Dialog(QWidget *parent): QDialog(parent), ui(new Ui::Dialog){ ui->setupUi(this); this->shareMemory = new QSharedMemory("shareMemoryExample"); this->setWindowTitle("sharedMemory Example"); connect(ui->loadImageButton,SIGNAL(clicked()),SLOT(loadFromFileSlots())); connect(ui->pushMemoryButton,SIGNAL(clicked()),SLOT(loadFromMemorySlots()));}Dialog::~Dialog(){ delete ui;}void Dialog::loadFromFileSlots(){ if(shareMemory->isAttached()) { if (!shareMemory->detach()) ui->label->setText(tr("Unable to detach from shared memory.")); } ui->label->setText("Select a Image File!"); QString fileName = QFileDialog::getOpenFileName(0,"Open a Image file",QDir::currentPath(),("Image (*.png *.bmp *.jpg)")); qDebug()<
label->setText("Select file is not an Image, please select another."); return; } // ui->label->setPixmap(QPixmap::fromImage(image)); QBuffer buffer; if(buffer.open(QIODevice::ReadWrite)) { QDataStream in(&buffer); in<
create(size)) { ui->label->setText("Unable to creat shared memory!"); return; } shareMemory->lock(); char *to = (char *)shareMemory->data(); const char *from = buffer.data().data(); memcpy(to,from,qMin(shareMemory->size(),size)); shareMemory->unlock(); }}void Dialog::loadFromMemorySlots(){ if(!shareMemory->attach()) { ui->label->setText("Unable to attach to shared memory segment.\n"); return; } QBuffer buffer; QDataStream in(&buffer); QImage image; shareMemory->lock(); buffer.setData((char*)shareMemory->constData(),shareMemory->size()); buffer.open(QBuffer::ReadOnly); in>>image; shareMemory->unlock(); shareMemory->detach(); ui->label->setPixmap(QPixmap::fromImage(image));}main.cpp#include "dialog.h"#include
int main(int argc, char *argv[]){ QApplication a(argc, argv); Dialog w; w.show(); return a.exec();}

转载地址:http://bzcg.baihongyu.com/

你可能感兴趣的文章
MySQL为Null会导致5个问题,个个致命!
查看>>
MySQL为什么不建议使用delete删除数据?
查看>>
MySQL主从、环境搭建、主从配制
查看>>
Mysql主从不同步
查看>>
mysql主从同步及清除信息
查看>>
MySQL主从同步相关-主从多久的延迟?
查看>>
mysql主从同步配置方法和原理
查看>>
mysql主从复制 master和slave配置的参数大全
查看>>
MySQL主从复制几个重要的启动选项
查看>>
MySQL主从复制及排错
查看>>
mysql主从复制及故障修复
查看>>
MySQL主从复制的原理和实践操作
查看>>
webpack loader配置全流程详解
查看>>
mysql主从复制,读写分离,半同步复制实现
查看>>
MySQL主从失败 错误Got fatal error 1236解决方法
查看>>
MySQL主从架构与读写分离实战
查看>>
MySQL主从篇:死磕主从复制中数据同步原理与优化
查看>>
mysql主从配置
查看>>
MySQL之2003-Can‘t connect to MySQL server on ‘localhost‘(10038)的解决办法
查看>>
MySQL之CRUD
查看>>