【Qt】基于QMediaPlayer的简易视频播放器

#include "mediaplayer.h" #include "ui_mediaplayer.h" #include <QMediaPlayer> #include <QVBoxLayout> #include <QVideoWidget> #include <QFileDialog> #include <QFile> #include <QMessageBox> #include <QTimer> #include "customslider.h" //播放视频的全局变量 QVBoxLayout* layout_video; QMediaPlayer* player; QVideoWidget* vWidget; //播放状态，true为播放，false为暂停 bool play_state; //与Slider有关的播放控制变量 QTimer * timer; int maxValue = 1000;//设置进度条的最大值 //音量控制slider CustomSlider * slider_volume; MediaPlayer::MediaPlayer(QWidget *parent) : QMainWindow(parent), ui(new Ui::MediaPlayer) { ui->setupUi(this); ui->pushButton_play_and_pause->setEnabled(false); ui->pushButton_volume->setEnabled(false); //禁用slider_progress，连接信号槽 ui->slider_progress->setEnabled(false); connect(ui->slider_progress,&CustomSlider::costomSliderClicked,this,&MediaPlayer::slider_progress_clicked); connect(ui->slider_progress,&CustomSlider::sliderMoved,this,&MediaPlayer::slider_progress_moved); connect(ui->slider_progress,&CustomSlider::sliderReleased,this,&MediaPlayer::slider_progress_released); slider_volume = new CustomSlider(this); slider_volume->setOrientation(Qt::Vertical); slider_volume->hide(); slider_volume->setEnabled(false); slider_volume->hide(); connect(slider_volume,&CustomSlider::costomSliderClicked,this,&MediaPlayer::slider_volume_changed); connect(slider_volume,&CustomSlider::sliderMoved,this,&MediaPlayer::slider_volume_changed); } //播放进度控制Slider的槽函数 void MediaPlayer::slider_progress_clicked() { player->setPosition(ui->slider_progress->value()*player->duration()/maxValue); } void MediaPlayer::slider_progress_moved() { //暂时停止计时器，在用户拖动过程中不修改slider的值 timer->stop(); player->setPosition(ui->slider_progress->value()*player->duration()/maxValue); } void MediaPlayer::slider_progress_released() { //用户释放滑块后，重启定时器 timer->start(); } //音量控制Slider的槽函数 void MediaPlayer::slider_volume_changed() { player->setVolume(slider_volume->value()); } MediaPlayer::~MediaPlayer() { delete ui; } void MediaPlayer::on_pushButton_open_file_clicked() { //实例化三个全局变量 layout_video = new QVBoxLayout; layout_video->setMargin(1); player = new QMediaPlayer; vWidget = new QVideoWidget; //根据label_player尺寸设置播放区域 vWidget->resize(ui->label_player->size()); layout_video->addWidget(vWidget); ui->label_player->setLayout(layout_video); player->setVideoOutput(vWidget); //选择视频文件 QString filename = QFileDialog::getOpenFileName(this,tr("选择视频文件"),".",tr("视频格式(*.avi *.mp4 *.flv *.mkv)")); QFile file(filename); if(!file.open(QIODevice::ReadOnly)) { QMessageBox::information(NULL, "Title", "Content", QMessageBox::Ok, QMessageBox::Ok); return; } //设置播放器 player->setMedia(QUrl::fromLocalFile(filename)); //play_state为true表示播放，false表示暂停 play_state = true; //启用播放/暂停按钮，并将其文本设置为“暂停” ui->pushButton_play_and_pause->setEnabled(true); ui->pushButton_play_and_pause->setText("暂停"); //播放器开启 player->play(); //启用slider并设置范围 ui->slider_progress->setEnabled(true); ui->slider_progress->setRange(0,maxValue); timer = new QTimer(); timer->setInterval(1000); timer->start(); //将timer连接至onTimerOut槽函数 connect(timer, SIGNAL(timeout()), this, SLOT(onTimerOut())); //启用音量控制slider slider_volume->setEnabled(true); slider_volume->setRange(0, 100); //启用音量按钮 ui->pushButton_volume->setEnabled(true); } void MediaPlayer::on_pushButton_play_and_pause_clicked() { //反转播放状态 if(play_state) { player->pause(); ui->pushButton_play_and_pause->setText("播放"); } else { player->play(); ui->pushButton_play_and_pause->setText("暂停"); } play_state = !play_state; } void MediaPlayer::onTimerOut() { ui->slider_progress->setValue(player->position()*maxValue/player->duration()); } bool state_slider_volume = false; void MediaPlayer::on_pushButton_volume_clicked() { if(state_slider_volume) { slider_volume->hide(); } else { slider_volume->setValue(player->volume()); slider_volume->setGeometry(QRect(ui->pushButton_volume->pos().rx()+0.5*ui->pushButton_volume->width()-15, ui->pushButton_volume->y()-100 , 30, 102)); slider_volume->show(); } state_slider_volume = !state_slider_volume; }