QMediaPlayer and QMediaPlaylist - problem with next

maniek1310

Crashes, I just click on the "Next"

SGaist

What does a run with the debugger tell you ?

maniek1310

http://imageshack.com/a/img199/3483/1ljx.png

Console : Rozpoczęto debugowanie
QEventLoop: Cannot be used without QApplication
QObject::connect: Cannot connect (null)::aboutToQuit() to QNativeWifiEngine::closeHandle()

SGaist

How does your main.cpp look like ?

Also, why make player and playlist static ?

maniek1310

main.cpp
@#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();

return a.exec&#40;&#41;;

}
@

mainwindow.h
@#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private slots:
void on_pushButton_clicked();

void on_pushButton_2_clicked();

void on_horizontalSlider_sliderMoved(int position);

void aktualna_pozycja(qint64 position);

void on_pushButton_3_clicked();

void run_file&#40;QString file&#41;;

void on_pause_clicked();

void on_next_file_clicked();

void on_pushButton_4_clicked();

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H
@

test_sound.pro
@#-------------------------------------------------

Project created by QtCreator 2014-02-04T19:08:13

#-------------------------------------------------

QT += core gui
QT += widgets multimedia
QT += multimedia
QT += core gui multimedia

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = test_sound
TEMPLATE = app

SOURCES += main.cpp
mainwindow.cpp

HEADERS += mainwindow.h

FORMS += mainwindow.ui
@

SGaist

Looks right.

Please move both player and playlist has non static member variable of MainWindow and try again

maniek1310

I do not understand. I could explain it somehow differently?

SGaist

@QMediaPlayer *player = new QMediaPlayer();
QMediaPlaylist *playlist = new QMediaPlaylist;@

These are static, remove them. And add two member variable in MainWindow to replace them.

@mainwindow.h
class MainWindow : public QMainWindow {
…

private:
QMediaPlayer *_player;
QMediaPlaylist *_playlist;

}

mainwindow.cpp

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow),
_player(new QMediaPlayer),
_playlist(new QMediaPlayList)
{
ui->setupUi(this);

QObject::connect(_player, SIGNAL(positionChanged(qint64)), this, SLOT(aktualna_pozycja(qint64)));

}
@

Something like that

maniek1310

@mainwindow.h
...
private:
Ui::MainWindow *ui;
QMediaPlayer *player;
QMediaPlayer *playlist;
};@

@mainwindow.cpp
...
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow),
player(new QMediaPlayer),
playlist(new QMediaPlaylist)
{
ui->setupUi(this);

QObject::connect(player, SIGNAL(positionChanged(qint64)), this, SLOT(aktualna_pozycja(qint64)));

}
...
@

błąd: cannot convert 'QMediaPlaylist*' to 'QMediaPlayer*' in initialization
playlist(new QMediaPlaylist)

błąd: 'class QMediaPlayer' has no member named 'addMedia' playlist->addMedia(QUrl::fromLocalFile(file));

SGaist

The error is pretty clear, you declared playlist list as a QMediaPlayer and not QMediaPlayList.

maniek1310

Okay, thank you. Now the program compiles correctly, but it is still the same problem.

After pressing the "Next" button shows up is:

http://imageshack.com/a/img577/9630/0p87.png

SGaist

Run your program using the debugger, that should catch the problem

maniek1310

http://imageshack.com/a/img199/3483/1ljx.png