qt更新ui通过线程 [英] qt-updating ui by thread

问题描述

hi我有一个线程更新ui的问题。
代码工作正常，但问题是当我想移动我的窗口，因为你知道在那一刻ui线程将停止更新。和我的线程发送值到停止的线程，导致错误。
我不知道如何解决这个问题。

hi I have a problem with updating ui by a thread. code works correctly but the problem is when I want to move my window as you know in that moment ui thread will stop updating. and my thread sends values to stopped thread that causes error. I don't know how to fix this.

这里是我的线程代码标题：

here is my thread code header:

#ifndef READERTHREAD_H
#define READERTHREAD_H
#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>
#include <QThread>

class readerThread : public QThread
{
    Q_OBJECT
public:
    explicit readerThread(QObject *parent = 0);
    void run();
    bool stop = false;
    QByteArray port_input;
    QByteArray payload;
    quint8 starter_symbol = 0;
    quint8 message_length = 0;
    quint8 message_ID = 0;
    readerThread *thread;
signals:
    void updated(QByteArray , quint8);

private:
    QSerialPort *serial;

};

#endif // READERTHREAD_H

我的主题.cpp：

#include "readerthread.h"
#include <QtCore>

readerThread::readerThread(QObject *parent) :
    QThread(parent)
{

    serial = new QSerialPort(this);

    foreach (const QSerialPortInfo &serialPortInfo, QSerialPortInfo::availablePorts())
    serial->setPortName(serialPortInfo.portName());

    serial->setBaudRate(QSerialPort::Baud115200);

    serial->setDataBits(QSerialPort::Data8);

    serial->setParity(QSerialPort::NoParity);

    serial->setFlowControl(QSerialPort::NoFlowControl);

    serial->setStopBits(QSerialPort::OneStop);

//    serial->setReadBufferSize(8192);

    serial->open(QIODevice::ReadOnly);

    serial->errorString();

}

void readerThread::run()
{
    while(serial->isOpen())
    {
        port_input.append(serial->readAll());
        if(port_input.count() >= 150)
        {
           starter_symbol = port_input.indexOf(254);
           if((port_input.at(starter_symbol + 3) == 01) && (port_input.at(starter_symbol + 4) == 01))
           {
              message_length = port_input.at(starter_symbol + 1);
              message_ID = port_input.at(starter_symbol + 5);
              payload = port_input.mid(starter_symbol + 6 , message_length);
              port_input.remove(starter_symbol , message_length + 8);
              emit updated(payload , message_ID);
           }
           port_input.remove(0 , starter_symbol);
        }
    }
}

这里我的mainwindow.cpp

and here my mainwindow.cpp in short :

   struct mavlink_attitude_t
        {
            /// <summary> Timestamp (milliseconds since system boot) </summary>
              quint32 time_boot_ms;
                /// <summary> Roll angle (rad, -pi..+pi) </summary>
              float roll;
                /// <summary> Pitch angle (rad, -pi..+pi) </summary>
              float pitch;
                /// <summary> Yaw angle (rad, -pi..+pi) </summary>
              float yaw;
                /// <summary> Roll angular speed (rad/s) </summary>
              float rollspeed;
                /// <summary> Pitch angular speed (rad/s) </summary>
              float pitchspeed;
                /// <summary> Yaw angular speed (rad/s) </summary>
              float yawspeed;

        };

    MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
        thread = new readerThread(this);
        connect(thread , SIGNAL(updated(QByteArray,quint8)) , this , SLOT(onUpdate(QByteArray,quint8)));
        thread->start();

    }

        void MainWindow::onUpdate(QByteArray payload , quint8 ID)
        {
               mavlink_attitude_t data;
               memcpy(&data,payload.data(),sizeof(mavlink_attitude_t));
               ui->timebootms->setText(QString::number(data.time_boot_ms));
               ui->roll->setText(QString::number(data.roll));
               ui->pitch->setText(QString::number(data.pitch));
               ui->yaw->setText(QString::number(data.yaw));
               ui->rollspeed->setText(QString::number(data.rollspeed));
               ui->pitchspeed->setText(QString::number(data.pitchspeed));
               ui->yawspeed->setText(QString::number(data.yawspeed));
        }

推荐答案

我们在前面修正了5.5版本：

You are likely hitting this issue that we fixed a while ago for the 5.5 release:

窗口正在调整大小或移动时停止流式传输

如果您愿意，可以撤消更改。

You can backport the change if you wish.

更重要的是，当库设计为具有异步API时，使用自己的线程是相对奇怪的。我写了一个简单的例子，然后演示了正确的异步使用库的读取目的。您可以在这里找到它：

More importantly, it is relatively strange to use threading on your own when the library is designed to have an async API. I wrote a simple example back then that demonstrates the proper async use of the library for reading purposes. Here can you find it:

命令行读取器异步示例

这篇关于qt更新ui通过线程的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！