有上传本地音乐文件，播放，暂停，拖拉进度条等功能的播放器。

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMediaPlayer>
#include <QFileDialog>
#include <QTime>
MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);player = new QMediaPlayer(this);// 当播放状态改变时，更新按钮的状态connect(player,&QMediaPlayer::stateChanged,this,&MainWindow::onStateChanged);// 当音乐文件的总时间改变时，更新滑块的范围connect(player, &QMediaPlayer::durationChanged, ui->slider, &QSlider::setMaximum);// 当播放位置改变时，更新滑块的值connect(player, &QMediaPlayer::positionChanged, ui->slider, &QSlider::setValue);// 当滑块的值改变时，设置播放位置connect(ui->slider, &QSlider::valueChanged, player, &QMediaPlayer::setPosition);connect(ui->slider, &QSlider::valueChanged, [this](int value) {// 将滑块的值转换为时间格式，并更新 timelabelQTime time(0, value / 60, value % 60);ui->timelabel->setText(time.toString("mm:ss"));});}MainWindow::~MainWindow()
{delete ui;
}void MainWindow::on_playButton_clicked()
{//if(player->state() == QMediaPlayer::PlayingState)//{//player->pause();//}else{//player->play();//}player->play();
}void MainWindow::onStateChanged(QMediaPlayer::State state)
{//if(state == QMediaPlayer::PlayingState)//{//ui->playButton->setText("Pause");//}//else//{//ui->playButton->setText("Play");//}
}void MainWindow::on_openAction_triggered()
{QString filename = QFileDialog::getOpenFileName(this, "Open a File", "", "Audio File(*.mp3)");player->setMedia(QUrl::fromLocalFile(filename));player->play();
}void MainWindow::on_pauseButton_clicked()
{player->pause();
}void MainWindow::on_OpenFileButton_clicked()
{on_openAction_triggered();
}void MainWindow::on_slider_actionTriggered(int action)
{}void MainWindow::on_timelabel_linkActivated(const QString &link)
{}

.h：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QMediaPlayer>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();private slots:void on_timelabel_linkActivated(const QString &link);void on_playButton_clicked();void on_slider_actionTriggered(int action);void on_pauseButton_clicked();void onStateChanged(QMediaPlayer::State state);void on_openAction_triggered();void on_OpenFileButton_clicked();private:Ui::MainWindow *ui;QMediaPlayer *player;
};
#endif // MAINWINDOW_H

.pro：

QT       += core gui
QT       += multimediagreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsCONFIG += c++11# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0SOURCES += \main.cpp \mainwindow.cppHEADERS += \mainwindow.hFORMS += \mainwindow.ui# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target