Cannot setText() QLabel with QMediaPlayer on the Mainwindow

mosleim

QT       += core gui multimedia multimediawidgets
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = DisplayAntrianSQ
TEMPLATE = app
DEFINES += QT_DEPRECATED_WARNINGS

SOURCES += \
        main.cpp \
        mainwindow_1366x768.cpp

HEADERS += \
    mainwindow_1366x768.h

FORMS += \
    mainwindow_1366x768.ui

RESOURCES += \
    resources.qrc

my main.cpp

#include "mainwindow_1366x768.h"
#include <QApplication>


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    MainWindow_1366x768 * mainwindow;

    mainwindow = new MainWindow_1366x768;
    mainwindow->showFullScreen();

    return a.exec();
}

my MainWindow

#ifndef MAINWINDOW_1366x768_H
#define MAINWINDOW_1366x768_H

#include <QMainWindow>
#include <QTimer>
#include <QDateTime>
#include <QMediaPlayer>
#include <QVideoWidget>
#include <QVBoxLayout>
#include <QKeyEvent>
namespace Ui {
class MainWindow_1366x768;
}


class MainWindow_1366x768 : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow_1366x768(QWidget *parent = 0);
    ~MainWindow_1366x768();
protected:
    void keyPressEvent(QKeyEvent *event);
private:
    Ui::MainWindow_1366x768 *ui;

    QTimer * timer;
    QDateTime * dt;

    QMediaPlayer * player;
    QVideoWidget * videoWidget;
    QVBoxLayout * ly;

    void buatVideoPlayer();
    bool first;

public slots:
    void updateJamHariTanggal();
};

#endif // MAINWINDOW_H

And

#include "mainwindow_1366x768.h"
#include "ui_mainwindow_1366x768.h"
#include <QFile>
#include <QDebug>
#include <QDir>
MainWindow_1366x768::MainWindow_1366x768(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow_1366x768),
    first(true)
{
    ui->setupUi(this);
    timer = new QTimer(this);
    dt = new QDateTime();
    timer->start(1000);

    connect(timer, SIGNAL(timeout()), this, SLOT(updateJamHariTanggal()));
    buatVideoPlayer();
}

MainWindow_1366x768::~MainWindow_1366x768()
{
    delete ui;
    delete dt;
    delete ly;
}
void MainWindow_1366x768::updateJamHariTanggal()
{
    ui->lblJam->setText(dt->currentDateTime().time().toString("  HH:mm:ss"));
    ui->lblHariTanggal->setText(dt->currentDateTime().date().toString("dddd, dd MMMM yyyy"));
    qDebug()<<"Time must update, but not. why?";
}

void MainWindow_1366x768::buatVideoPlayer()
{
        player = new QMediaPlayer(this);
        videoWidget = new QVideoWidget(this);
        // when i comment this line below, i can update mu QLable ui->lblJam
        player->setVideoOutput(videoWidget);

        ly = new QVBoxLayout;
        ly->addWidget(videoWidget);
        videoWidget->setAspectRatioMode(Qt::IgnoreAspectRatio);
        ly->setMargin(0);
        ui->widVideo->setLayout(ly);
        player->setMedia(QUrl::fromLocalFile(QDir::currentPath()+"/media/tt.mp4"));
        player->play();
}
void MainWindow_1366x768::keyPressEvent(QKeyEvent *event)
{
    if(event->key()==Qt::Key_Escape)
        close();
}

this code is working in linux(Ubuntu 16.04). but, when i use in windows 7 and 10, my QLabel cannot updated.
i can update when i comment this line:

// when i comment this line below, i can update mu QLable ui->lblJam
player->setVideoOutput(videoWidget);

how to solve this my problem?

koahnig

@mosleim said in Cannot setText() QLabel with QMediaPlayer on the Mainwindow:

this code is working in linux(Ubuntu 6.04). but, when i use in windows 7 and 10, my QLabel cannot updated.

Most likely you have a typing error in Ubuntu version. I guess you mean 16.04.

More important might be the Qt versions you are using on different platforms.

Unfortunately I have no experience with QMediapLayer. I could not see an obvious problem.

You can check also on JIRA for eventual bug reports.

SGaist

Hi,

To add to @koahnig, what version of Qt are you using ?

Did you check the errors of video widget to see how thing are going around ?

mosleim

My Qt version is Qt5.10. No warning or error triggerred.

SGaist

Silly question but, what happens if you don't start the video playing rather than not set the video output on Windows ?

mosleim

@SGaist the text still not updated.

I have clear and rebuild. But still not updated.

I create new project and copy paste the source, the label text can updated. 😭😭😭

koahnig

@mosleim

May be a stupid question or comment. But did you rerun qmake in creator too?

SGaist

Where's your QLabel located ?

mosleim

@SGaist in mainwindow form.

@koahnig i have rerun qmake. But, still problem. I have copypaste the project and cross compile from linux for windows. Same problem.

? Offline

It would be helpful if you post the content of the 'ui_mainwindow_1366x768.h' file.

atruin

Has anyone solved this problem? I encountered this problem too. If a QMediaPlayer is showup in a window, all control in that window won't show the updated UI. So if a QLabel has changed it's text content, you would 't see it. I suspect it has something to do with Media paint event. One (maybe) stupid way to workaround is use QMediaPlayer's unbind method to disconnect QVideoWidget with QMediaPlayer.