代码如下
//ui_mainwindow.h #ifndef UI_MAINWINDOW_H #define UI_MAINWINDOW_H #include #include #include #include #include #include #include #include #include #include #include #include QT_BEGIN_NAMESPACE class Ui_MainWindow { public: QWidget *centralWidget; QPushButton *writeButton; QPushButton *readButton; QPushButton *closeButton; QLabel *dis_label; QMenuBar *menuBar; QToolBar *mainToolBar; QStatusBar *statusBar; void setupUi(QMainWindow *MainWindow) { if (MainWindow->objectName().isEmpty()) MainWindow->setObjectName(QString::fromUtf8("MainWindow")); MainWindow->resize(600, 400); centralWidget = new QWidget(MainWindow); centralWidget->setObjectName(QString::fromUtf8("centralWidget")); writeButton = new QPushButton(centralWidget); writeButton->setObjectName(QString::fromUtf8("writeButton")); writeButton->setGeometry(QRect(100, 210, 75, 23)); readButton = new QPushButton(centralWidget); readButton->setObjectName(QString::fromUtf8("readButton")); readButton->setGeometry(QRect(240, 210, 75, 23)); closeButton = new QPushButton(centralWidget); closeButton->setObjectName(QString::fromUtf8("closeButton")); closeButton->setGeometry(QRect(390, 210, 75, 23)); dis_label = new QLabel(centralWidget); dis_label->setObjectName(QString::fromUtf8("dis_label")); dis_label->setGeometry(QRect(200, 90, 191, 16)); MainWindow->setCentralWidget(centralWidget); menuBar = new QMenuBar(MainWindow); menuBar->setObjectName(QString::fromUtf8("menuBar")); menuBar->setGeometry(QRect(0, 0, 600, 19)); MainWindow->setMenuBar(menuBar); mainToolBar = new QToolBar(MainWindow); mainToolBar->setObjectName(QString::fromUtf8("mainToolBar")); MainWindow->addToolBar(Qt::TopToolBarArea, mainToolBar); statusBar = new QStatusBar(MainWindow); statusBar->setObjectName(QString::fromUtf8("statusBar")); MainWindow->setStatusBar(statusBar); retranslateUi(MainWindow); QMetaObject::connectSlotsByName(MainWindow); } // setupUi void retranslateUi(QMainWindow *MainWindow) { MainWindow->setWindowTitle(QApplication::translate("MainWindow", "MainWindow", 0, QApplication::UnicodeUTF8)); writeButton->setText(QApplication::translate("MainWindow", "PushButton", 0, QApplication::UnicodeUTF8)); readButton->setText(QApplication::translate("MainWindow", "PushButton", 0, QApplication::UnicodeUTF8)); closeButton->setText(QApplication::translate("MainWindow", "PushButton", 0, QApplication::UnicodeUTF8)); dis_label->setText(QApplication::translate("MainWindow", "TextLabel", 0, QApplication::UnicodeUTF8)); } // retranslateUi }; namespace Ui { class MainWindow: public Ui_MainWindow {}; } // namespace Ui QT_END_NAMESPACE #endif // UI_MAINWINDOW_H //thread.h #ifndef THREAD_H #define THREAD_H #include class Thread:public QThread { Q_OBJECT public: Thread(); char buf[128]; volatile bool stopped; volatile bool write_rs; volatile bool read_rs; protected: virtual void run(); }; #endif //thread.cpp #include"thread.h" #include #include #include #include //串口用到的 #include #include #include #include #define BAUDRATE B9600 #define RS_DEVICE "/dev/ttyS0" //串口0 //#define RS_DEVICE "/dev/ttySAC1" //串口1 Thread::Thread() {} //析构 void Thread::run() //这就是线程的具体工作了 { int fd,c=0,res; struct termios oldtio,newtio; //termios结构是用来保存波特率、字符大小等 printf("start.../n"); fd=open(RS_DEVICE,O_RDWR|O_NOCTTY); //以读写方式打开串口。不控制TTY if(fd<0) { perror("error"); exit(1); //失败退出 } printf("Open.../n"); tcgetattr(fd,&oldtio); //保存当前设置到oldtio bzero(&newtio,sizeof(newtio)); //清除newtio结构，并重新对它的成员设置如下 newtio.c_cflag=BAUDRATE|CS8|CLOCAL|CREAD; //9600、8位、忽略DCD信号、启用接收装置 newtio.c_iflag|=IGNPAR; //忽略奇偶 newtio.c_oflag=0; newtio.c_lflag=0; newtio.c_cc[VMIN]=0; newtio.c_cc[VTIME]=100; //在规定时间(VTIME)内读取(VMIN)个字符; tcflush(fd,TCIFLUSH); //清除所有队列在串口的输入与输出； tcsetattr(fd,TCSANOW,&newtio); //把我们的设置写入termios while(stopped) //stopped为0时将退出线程 { if(write_rs) //write_rs为1时把字符串从串口中输出 { write_rs=0; write(fd,"QtEmbedded-4.5.1",16); //向串口中写入字符，通过串口调试助手可看到QtEmbedded-4.5.1这个字符 } if(read_rs) //read_rs为1时读取，并存在buf { read_rs=0; res=read(fd,buf,10); //读取串口的数据到buf buf[res]=0; emit finished(); //读完后发一个信号 } } printf("Close.../n"); tcsetattr(fd,TCSANOW,&oldtio); //重新设置回原来的 close(fd); quit(); } //mainwindow.h #ifndef MAINWINDOW_H #define MAINWINDOW_H #include #include"ui_mainwindow.h" //奇怪?这个头文件从哪里来的？呵呵,刚才用designer做的mainwindow.ui文件，经过make后会生成这个头文件， #include"thread.h" //把我们前面定义的线程包含进来 class MainWindow:public QMainWindow,public Ui::MainWindow //多继承 { Q_OBJECT public: MainWindow(QWidget *parent=0); public slots: void writeThread(); void readThread(); void closeThread(); void display(); private: Thread *yy; }; #endif //mainwindow.cpp #include"mainwindow.h" MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent) { setupUi(this); yy = new Thread; yy->start(); //启动线程 yy->stopped=1; //初始化变量 yy->write_rs=0; yy->read_rs=0; connect(writeButton,SIGNAL(clicked()),this,SLOT(writeThread())); //信号与槽 connect(readButton,SIGNAL(clicked()),this,SLOT(readThread())); connect(closeButton,SIGNAL(clicked()),this,SLOT(closeThread())); connect(yy,SIGNAL(finished()),this,SLOT(display())); //前面线程读完了不是发一个信号么，这个信号就是发到这个槽 } void MainWindow::display() { dis_label->setText(yy->buf); //读到的在dis_label显示，dis_label就是我们前面designer放的标签，显示buf中的内容 } void MainWindow::writeThread() //前面线程都是根据stopped、write_rs、read_rs的状态来工作的^_^ { yy->write_rs=1; } void MainWindow::readThread() { yy->read_rs=1; } void MainWindow::closeThread() { yy->stopped=0; } //main.cpp #include #include"mainwindow.h" int main(int argc,char *argv[]) { QApplication app(argc,argv); MainWindow mw; mw.show(); return app.exec(); }
本例中用到了线程，线程有一个好处就是可以单独的去扫描串行端口，当有数据发送到端口时，显示相应的字符到显示框中。
使用时注意波特率和串口的设置，这里用的波特率是9600，串口时ttyS0
