Qt实战-------音乐播放器

本是古典何须时尚 2022-12-22 08:48 188阅读 0赞

### 文章目录 ###

*  开发工具
 *  效果展示
 *  思路方法
 *  源代码

# 开发工具 #

Qt Creator

# 效果展示 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1ODkzOTk5_size_16_color_FFFFFF_t_70_pic_center]

# 思路方法 #

首先加入multimedia和multimediawidgets模块  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1ODkzOTk5_size_16_color_FFFFFF_t_70_pic_center 1]  
定义一个播放器，和播放列表，  
![在这里插入图片描述][20201118185949774.png_pic_center]![在这里插入图片描述][20201118185825814.png_pic_center]

# 源代码 #

widget.h头文件

#ifndef WIDGET_H
    #define WIDGET_H
    
    #include <QWidget>
    #include<QMediaPlayer>
    #include<QMediaPlaylist>
    #include<QFile>
    #include<QFileDialog>
    namespace Ui {
        
    class Widget;
    }
    
    class Widget : public QWidget
    {
        
        Q_OBJECT
    
    public:
        explicit Widget(QWidget *parent = nullptr);
        ~Widget();
    private slots:
        void on_btnAdd_clicked();
    
        void on_btnMove_clicked();
    
        void on_btnRemove_clicked();
    
        void on_btnPlay_clicked();
    
        void on_btnPause_clicked();
    
        void on_btnStop_clicked();
    
        void on_btnPrevious_clicked();
    
        void on_btnNext_clicked();
    
        void on_SliderVoice_valueChanged(int value);
    
        void on_SliderTime_valueChanged(int value);
    
        void on_listView_doubleClicked(const QModelIndex &index);
    private slots:
        void onStateChanged(QMediaPlayer::State state);   //接受当前播放改变状态的
        void onPlaylistChanged(int position);            //当前文件播放列表变化
        void onDurationChanged(qint64 duration);         //当前总时长发生变化
        void onPositionChanged(qint64 position);          //每个文件发生变化，播放进度
    private:
        QMediaPlayer* player;//播放器
        QMediaPlaylist* playlist;//播放列表
        QString durationTime;     //音频文件总时长
        QString positionTime;//当前播放到位置
    
    private:
        Ui::Widget *ui;
    };
    
    #endif // WIDGET_H

widget.cpp文件

#include "widget.h"
    #include "ui_widget.h"
    
    Widget::Widget(QWidget *parent) :
        QWidget(parent),
        ui(new Ui::Widget)
    {
        
        ui->setupUi(this);
        this->setWindowTitle(tr("音乐播放器"));
        player = new QMediaPlayer(this);
        playlist = new QMediaPlaylist(this);
        playlist->setPlaybackMode(QMediaPlaylist::Loop);//设置循环播放
        player->setPlaylist(playlist);
        connect(player, SIGNAL(stateChanged(QMediaPlayer::State)), this, SLOT(onStateChanged(QMediaPlayer::State)));
        connect(player, SIGNAL(positionChanged(qint64)), this, SLOT(onPositionChanged(qint64)));
        connect(player, SIGNAL(durationChanged(qint64)), this, SLOT(onDurationChanged(qint64)));
        connect(playlist,SIGNAL(currentIndexChanged(int)),this,SLOT(onPlaylistChanged(int)));
    }
    
    Widget::~Widget()
    {
        
        delete ui;
    }
    //添加文件
    void Widget::on_btnAdd_clicked()
    {
        
        QString strPath = QDir::homePath();
        QString strTitle = "请选择文件";
        //过滤器
        QString file = "音频文件(*.mp3 *.wav *.wma);;mp3文件(*.mp3);;wav文件(*.wav);;所有文件(*.*)";
        QStringList fileList = QFileDialog::getOpenFileNames(this,strTitle,strPath,file);
       if(fileList.count()<1)
       {
        
           return;
       }
       for(int i = 0;i < fileList.count();i++)
       {
        
           QString aFile = fileList.at(i);
           playlist->addMedia(QUrl::fromLocalFile(aFile));//添加本地文件
           QFileInfo fileInfo(aFile);
           ui->listWidget->addItem(fileInfo.fileName());//将文件添加到列表中
       }
       if(player->state() == QMediaPlayer::PlayingState)//正在播放
       {
        
           playlist->setCurrentIndex(0);//从第一个开始播放
       }
       player->play();
    }
    
    void Widget::on_btnMove_clicked()
    {
        
        int pos = ui->listWidget->currentRow();
        QListWidgetItem* item = ui->listWidget->takeItem(pos);
        delete item;//从listWidget列表中华删除
        if (playlist->currentIndex() == pos)
        {
        
            int npos = 0;
            if (pos > 1)
                npos = pos - 1;
            playlist->removeMedia(pos);
            if (ui->listWidget->count() > 0)
            {
        
                playlist->setCurrentIndex(npos);
                onPlaylistChanged(npos);
            }
            else
            {
        
                player->stop();
                ui->labName->setText("无曲目");
            }
        }
        else
            playlist->removeMedia(pos);
    }
    
    void Widget::on_btnRemove_clicked()
    {
        
        playlist->clear();
        ui->listWidget->clear();
        player->stop();
    }
    //播放
    void Widget::on_btnPlay_clicked()
    {
        
        if(playlist->currentIndex()<0)
        {
        
            playlist->setCurrentIndex(0);
        }
        player->play();
    }
    //暂停
    void Widget::on_btnPause_clicked()
    {
        
        player->pause();
    }
    //停止
    void Widget::on_btnStop_clicked()
    {
        
        player->stop();
    }
    
    void Widget::on_btnPrevious_clicked()
    {
        
        playlist->previous();
    }
    
    void Widget::on_btnNext_clicked()
    {
        
        playlist->next();
    }
    
    void Widget::on_SliderVoice_valueChanged(int value)
    {
        
        player->setVolume(value);
    }
    
    void Widget::on_SliderTime_valueChanged(int value)
    {
        
        player->setPosition(value);
    }
    //双击列表
    void Widget::on_listView_doubleClicked(const QModelIndex &index)
    {
        
        int nRow = index.row();//需要播放的文件索引
        playlist->setCurrentIndex(nRow);
        player->play();//播放
    }
    //播放器状态变化，更新按钮状态
    void Widget::onStateChanged(QMediaPlayer::State state)
    {
        
        ui->btnPlay->setEnabled(!(state == QMediaPlayer::PlayingState));//开始按钮
        ui->btnPause->setEnabled(state == QMediaPlayer::PlayingState);//暂停按钮禁用
        ui->btnStop->setEnabled(state ==QMediaPlayer::PlayingState);//停止按钮禁用
    }
    //播放列表变化,更新当前播放文件名显示
    void Widget::onPlaylistChanged(int position)
    {
        
        ui->listWidget->setCurrentRow(position);
        QListWidgetItem *item = ui->listWidget->currentItem();
        if(item)
        {
        
            ui->labName->setText(item->text());
        }
    }
    //文件时长变化，更新进度显示
    void Widget::onDurationChanged(qint64 duration)
    {
        
        ui->SliderTime->setMaximum(duration);//总共时长
        int secs = duration/1000;
        int mins = secs /60;//分钟
        secs = secs % 60;//秒
        durationTime = QString::asprintf("%d:%d",mins,secs);
        ui->labTime->setText(positionTime+ "/"+duration);
    }
    //当前文件播放位置变化，更新进度显示
    void Widget::onPositionChanged(qint64 position)
    {
        
        //如果正在拖动
        if(ui->SliderTime->isSliderDown())
        {
        
            return;
        }
        ui->SliderTime->setSliderPosition(position);
        int secs = position/1000;
        int mins = secs /60;//分钟
        secs = secs % 60;//秒
        positionTime = QString::asprintf("%d:%d",mins,secs);
        ui->labTime->setText(positionTime+ "/"+durationTime);
    }

main.cpp

#include "widget.h"
    #include <QApplication>
    
    int main(int argc, char *argv[])
    {
        
        QApplication a(argc, argv);
        Widget w;
        w.show();
    
        return a.exec();
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1ODkzOTk5_size_16_color_FFFFFF_t_70_pic_center]: /images/20221120/e3366c572829447e909be10e80404f74.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1ODkzOTk5_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221120/e3a5a951653143c2a7b33d7b79ee3c63.png
[20201118185949774.png_pic_center]: https://img-blog.csdnimg.cn/20201118185949774.png#pic_center
[20201118185825814.png_pic_center]: /images/20221120/ae83f59dbfce4d0f93b9a576c1884254.png