求一种基于Linux的Qt图形化MP3播放器的设计方案

嵌入式课程设计总结（基于Linux的Qt版MP3播放器）

废话不多写直接上图上代码，其中有很多不规范的地方，希望大佬们指正。
1.课设题目

设计一个MP3播放器，要求：使用Linux下的madplay进行歌曲的播放，一共有三大项：

• Linux下字符界面实现Mp3播放器
  
• 将字符界面移植到ARM板上运行
  
• Qt图形化Mp3界面
  
  

在本次课程设计中我主要负责Qt图形化的设计开发。
2.设计思路

• 使用双向循环链表存放添加的歌曲
  
• 使用system("madplay xxx.mp3 &");进行歌曲的播放
  
• 调用的图片使用与.mp3文件同样的文件名，只是后缀不同，则操作字符串即可进行调用（这个思路有点low,验收时老师说应该用解析MP3文件的方法）
  
• 界面分为主界面和播放界面，每首歌的专辑图和播放背景都不同，在播放的时候切换图片，播放的同时展示歌词和正在播放的歌曲名
  
• 几个主要的按钮：播放，暂停，上一曲，下一曲，随机播放
  
• 添加歌曲后会在列表中展示，并计数
  
• 删除列表中的歌曲，若被删除的歌曲当前正在播放，则跳回主界面
  
• 错误操作弹窗提示错误，错误操作包括：重复添加歌曲，歌曲列表没有歌曲时点击播放歌曲
  
  

3.主界面展示

4.布局

• widget.ui
  
  

2. smallwidget.ui

5.控件的使用

• 按钮:QPushButton
  
• 歌词：TextEdit
  
• 歌词列表:ListWidget
  
• 正在播放：LineEdit
  
• 专辑图片：label
  
• 音量：SpinBox+horizontalSlider
  
• 小图标：label
  
• 标题文字：label
  
• 错误弹窗：QMessageBox
  
  

6.核心代码

• wiget.h
  
  

#ifndef WIDGET_H
#define WIDGET_H


#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include


QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE


class Widget : public QWidget
{
    Q_OBJECT


public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void on_pushbutton_click();
    QMainWindow *qmainwindow;


    bool AddNode(const char *songName,const char* path);
    void InitializeList();
    char *MoveNext();
    char *MovePrevious();
    void RemoveNode(QString s);




private slots:
    void on_pushButton_5_clicked();


    void on_listWidget_itemClicked(QListWidgetItem *item);


    //void on_pushButton_3_clicked();


    //void on_pushButton_4_clicked();


    void on_pushButton_2_clicked();
    //void keyPressEvent( QKeyEvent *k );


    void on_pushButton_6_clicked();


//    void on_mySlider_sliderReleased();


//    void on_mySlider_sliderMoved(int position);


private:
    Ui::Widget *ui;


};
#endif // WIDGET_H

• 双向列表
  
  

//Double director circle ListNode
struct Node
{
    char songName[512];
    struct Node *next;
    struct Node *prev;
    int flag;
    char path[1024];
};
typedef struct Node* List;
static List head ;
static List tail ;
static List current;


void Widget::InitializeList()
{
    head =(struct Node*)malloc(sizeof(struct Node));


    tail = head;


    head->next = tail;
    head->prev = tail;


    //current = head->next;
    songNum = 0;
}




bool Widget::AddNode(const char *songName, const char *path)
{


        List pnew;
        List scan = head;


        pnew = (struct Node*)malloc(sizeof(struct Node));//在堆上创建节点
        if(pnew == NULL)
        {
            printf("malloc create errorn");
            return false;
        }


        strcpy(pnew->path,path);
        strcpy(pnew->songName,songName);
        pnew->next = NULL;
        pnew->prev = NULL;
        pnew->flag = 0;


        //judge overlap
        while(scan->next != tail){
            if(!strcmp(pnew->songName,scan->next->songName))
            {
                qDebug() << "this song already exists" << endl;
                return false;
            }
            scan = scan->next;//找打链表尾
        }


        pnew->prev = scan;
        pnew->next = tail;
        scan->next = pnew;
        tail->prev = pnew;


        songNum++;


        if(songNum == 1)
            current = head->next;


        return true;


}




char* Widget::MoveNext()
{
    if(current->next != tail){
        current = current->next;
    }
    else
    {
        current = head->next;
    }
    printf("this song is playing   %s",current->songName);
    return current->path; //fullname
}




char* Widget:: MovePrevious()
{
    if(current->prev != head)
    {
        current = current->prev;


    }
    else
    {
        current = head->prev;


    }
     printf("this song is playing   %sn",current->songName);
     return current->path;
}


void Widget::RemoveNode(QString s)
{
    while(current->songName != s)
    {
        current = current->next;
    }
    List temp = current;
    temp->next->prev = temp->prev;
    current->prev->next = current->next;


//    current->next->prev = current->prev;
}

• 播放键
  
  

//播放 pushButton_2
    connect(ui->pushButton_2,&QPushButton::clicked,this,[=](){
        //judge songList whether NULL
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        //"madplay /home/itcast/Desktop/1.mp3 &"
        // -s 0:0:01:11 set action time
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);


        if(flag)
        {
            if(buf!=onbuf)
            {
                system("killall -9 madplay");
                system(strChar);
                ui->lineEdit->setText(RealfileName);
                onbuf = buf;
            }
            else
            {
                //system("killall -9 madplay");
                system(strChar);
                ui->lineEdit->setText(RealfileName);
            }




        }
        else
        {
            system("killall -CONT madplay &");
            flag = 1;
            return;
        }


        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);


        //change current
        while(current->path != buf)
        {
            current = current->next;
        }




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);


        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";




        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        //palette.setBrush(QPalette::Background,QBrush(pixmap));
        //this->setPalette(palette);


        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });

• 暂停键
  
  

//暂停 pushButton
    connect(ui->pushButton,&QPushButton::clicked,this,[=](){
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        system("killall -STOP madplay &");
        flag = 0;
    });

• 上一曲
  
  

//last一曲
    connect(ui->pushButton_3,&QPushButton::clicked,this,[=](){
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }


        buf = QString(MovePrevious());
        onbuf = buf;
        system("killall -9 madplay");
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();


        system(strChar);
        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });

• 
  
  

嵌入式课程设计总结（基于Linux的Qt版MP3播放器）

废话不多写直接上图上代码，其中有很多不规范的地方，希望大佬们指正。
1.课设题目

设计一个MP3播放器，要求：使用Linux下的madplay进行歌曲的播放，一共有三大项：

• Linux下字符界面实现Mp3播放器
  
• 将字符界面移植到ARM板上运行
  
• Qt图形化Mp3界面
  
  

在本次课程设计中我主要负责Qt图形化的设计开发。
2.设计思路

• 使用双向循环链表存放添加的歌曲
  
• 使用system("madplay xxx.mp3 &");进行歌曲的播放
  
• 调用的图片使用与.mp3文件同样的文件名，只是后缀不同，则操作字符串即可进行调用（这个思路有点low,验收时老师说应该用解析MP3文件的方法）
  
• 界面分为主界面和播放界面，每首歌的专辑图和播放背景都不同，在播放的时候切换图片，播放的同时展示歌词和正在播放的歌曲名
  
• 几个主要的按钮：播放，暂停，上一曲，下一曲，随机播放
  
• 添加歌曲后会在列表中展示，并计数
  
• 删除列表中的歌曲，若被删除的歌曲当前正在播放，则跳回主界面
  
• 错误操作弹窗提示错误，错误操作包括：重复添加歌曲，歌曲列表没有歌曲时点击播放歌曲
  
  

3.主界面展示

4.布局

• widget.ui
  
  

2. smallwidget.ui

5.控件的使用

• 按钮:QPushButton
  
• 歌词：TextEdit
  
• 歌词列表:ListWidget
  
• 正在播放：LineEdit
  
• 专辑图片：label
  
• 音量：SpinBox+horizontalSlider
  
• 小图标：label
  
• 标题文字：label
  
• 错误弹窗：QMessageBox
  
  

6.核心代码

• wiget.h
  
  

#ifndef WIDGET_H
#define WIDGET_H


#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include


QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE


class Widget : public QWidget
{
    Q_OBJECT


public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
    void on_pushbutton_click();
    QMainWindow *qmainwindow;


    bool AddNode(const char *songName,const char* path);
    void InitializeList();
    char *MoveNext();
    char *MovePrevious();
    void RemoveNode(QString s);




private slots:
    void on_pushButton_5_clicked();


    void on_listWidget_itemClicked(QListWidgetItem *item);


    //void on_pushButton_3_clicked();


    //void on_pushButton_4_clicked();


    void on_pushButton_2_clicked();
    //void keyPressEvent( QKeyEvent *k );


    void on_pushButton_6_clicked();


//    void on_mySlider_sliderReleased();


//    void on_mySlider_sliderMoved(int position);


private:
    Ui::Widget *ui;


};
#endif // WIDGET_H

• 双向列表
  
  

//Double director circle ListNode
struct Node
{
    char songName[512];
    struct Node *next;
    struct Node *prev;
    int flag;
    char path[1024];
};
typedef struct Node* List;
static List head ;
static List tail ;
static List current;


void Widget::InitializeList()
{
    head =(struct Node*)malloc(sizeof(struct Node));


    tail = head;


    head->next = tail;
    head->prev = tail;


    //current = head->next;
    songNum = 0;
}




bool Widget::AddNode(const char *songName, const char *path)
{


        List pnew;
        List scan = head;


        pnew = (struct Node*)malloc(sizeof(struct Node));//在堆上创建节点
        if(pnew == NULL)
        {
            printf("malloc create errorn");
            return false;
        }


        strcpy(pnew->path,path);
        strcpy(pnew->songName,songName);
        pnew->next = NULL;
        pnew->prev = NULL;
        pnew->flag = 0;


        //judge overlap
        while(scan->next != tail){
            if(!strcmp(pnew->songName,scan->next->songName))
            {
                qDebug() << "this song already exists" << endl;
                return false;
            }
            scan = scan->next;//找打链表尾
        }


        pnew->prev = scan;
        pnew->next = tail;
        scan->next = pnew;
        tail->prev = pnew;


        songNum++;


        if(songNum == 1)
            current = head->next;


        return true;


}




char* Widget::MoveNext()
{
    if(current->next != tail){
        current = current->next;
    }
    else
    {
        current = head->next;
    }
    printf("this song is playing   %s",current->songName);
    return current->path; //fullname
}




char* Widget:: MovePrevious()
{
    if(current->prev != head)
    {
        current = current->prev;


    }
    else
    {
        current = head->prev;


    }
     printf("this song is playing   %sn",current->songName);
     return current->path;
}


void Widget::RemoveNode(QString s)
{
    while(current->songName != s)
    {
        current = current->next;
    }
    List temp = current;
    temp->next->prev = temp->prev;
    current->prev->next = current->next;


//    current->next->prev = current->prev;
}

• 播放键
  
  

//播放 pushButton_2
    connect(ui->pushButton_2,&QPushButton::clicked,this,[=](){
        //judge songList whether NULL
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        //"madplay /home/itcast/Desktop/1.mp3 &"
        // -s 0:0:01:11 set action time
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);


        if(flag)
        {
            if(buf!=onbuf)
            {
                system("killall -9 madplay");
                system(strChar);
                ui->lineEdit->setText(RealfileName);
                onbuf = buf;
            }
            else
            {
                //system("killall -9 madplay");
                system(strChar);
                ui->lineEdit->setText(RealfileName);
            }




        }
        else
        {
            system("killall -CONT madplay &");
            flag = 1;
            return;
        }


        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);


        //change current
        while(current->path != buf)
        {
            current = current->next;
        }




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);


        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";




        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        //palette.setBrush(QPalette::Background,QBrush(pixmap));
        //this->setPalette(palette);


        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });

• 暂停键
  
  

//暂停 pushButton
    connect(ui->pushButton,&QPushButton::clicked,this,[=](){
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        system("killall -STOP madplay &");
        flag = 0;
    });

• 上一曲
  
  

//last一曲
    connect(ui->pushButton_3,&QPushButton::clicked,this,[=](){
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }


        buf = QString(MovePrevious());
        onbuf = buf;
        system("killall -9 madplay");
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();


        system(strChar);
        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });

• 
  
  

举报

• 下一曲
  
  

//next一曲
    //buf = QString(MoveNext());
    connect(ui->pushButton_4,&QPushButton::clicked,this,[=](){


        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }


        //get filename
        buf = QString(MoveNext());
        onbuf = buf;
        //kill singing song
        system("killall -9 madplay");
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";
        const char* strChar = str.toLatin1();


        system(strChar);
        //qDebug() << "bofangyinyue xiayishou" <         //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);


        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });
随机播放键



//set button_7 random play
    connect(ui->pushButton_7,&QPushButton::clicked,this,[=](){
        //judge error by songNum
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        system("killall -9 madplay");




        //set randInt
        int randInt = rand()%10+1;




        for(int i = 0 ;i         {
            current = current->next;
        }
        if(current == head)
            current = current->next;
        buf = current->path;


        onbuf = buf;


        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();


        system(strChar);
        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);


    });

• 添加歌曲文件
  
  

void Widget::on_pushButton_5_clicked()
{


    //select song
    QFileDialog *fdlg = nullptr;
    QString fileName = fdlg->getOpenFileName(this,"open File","/home/itcast/Desktop","(*.mp3)");
    if(fileName == NULL)
        return;
    QString RealfileName = fileName.mid(fileName.lastIndexOf('/')+1);
   
    buf = fileName;
   
    //song add to List
    const char* rfn = RealfileName.toLatin1();
    const char* fn = fileName.toLatin1();
    printf("%s %sn",rfn,fn);
    bool flag = AddNode(rfn,fn);


    if(flag)
    {
        //add to QListWigetItem
        QListWidgetItem *item = new QListWidgetItem(QIcon(":Image/To-like.png"),RealfileName);
        ui->listWidget->addItem(item);
        item->setTextAlignment(Qt::AlignLeft);


        QString number = QString::number(songNum);
        ui->lineEdit_2->setText(number);
    }else{
        QMessageBox::critical(this,"error","overlap exists");
    }


}

• 点击ListWidgetItem进行歌曲切换
  
  

void Widget::on_listWidget_itemClicked(QListWidgetItem *item)
{
    buf = item->text();
    buf = "/home/itcast/Desktop/"+buf;


    //change current
    while(current->path != buf)
    {
        current = current->next;
    }
}

• 删除歌曲键
  
  

void Widget::on_pushButton_6_clicked()
{
    if(songNum == 0)
    {
        QMessageBox::critical(this,"critical","no songs in songList");
        return ;
    }
    QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);


    //foreach to find song to delete
    for(int i=0 ;i     {
        if(ui->listWidget->item(i)->text() == RealfileName)
        {
            ui->listWidget->takeItem(i);
            songNum--;


            //updata songNum
            QString number = QString::number(songNum);
            ui->lineEdit_2->setText(number);


            RemoveNode(RealfileName);
            QString filename = "/home/itcast/Desktop/"+RealfileName;
            if(onbuf == filename)
            {
                system("killall -9 madplay");


                //reset picture in label_4
                QMovie *myMovie = new QMovie(":Image/CD.png");
                ui->label_4->setMovie(myMovie);
                ui->label_4->setScaledContents(true);
                myMovie->start();


                ui->lineEdit->setText("");
                ui->textEdit->setText("");
                //reset widget background
                QPalette palette;
                this->setAutoFillBackground(true);
                QPixmap pixmap;
                pixmap.load(":Image/default.jpg");
                palette.setBrush(QPalette::Background,QBrush(pixmap));
                this->setPalette(palette);


                //set opacity
                QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
                opacityEffect2->setOpacity(1);
                ui->label_6->setGraphicsEffect(opacityEffect2);


            }
        }
    }
}

• 音量条
  
  

smallwidget.h

#ifndef SMALLWIDGET_H
#define SMALLWIDGET_H


#include
#include
#include


namespace Ui {
class smallwidget;
}


class smallwidget : public QWidget
{
    Q_OBJECT


public:
    explicit smallwidget(QWidget *parent = nullptr);
    ~smallwidget();


private slots:
    //void on_spinBox_valueChanged(const QString &arg1);
    //void keyPressEvent( QKeyEvent *k );


private:
    Ui::smallwidget *ui;
};
smallwidget.cpp

#include "smallwidget.h"
#include "ui_smallwidget.h"


smallwidget::smallwidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::smallwidget)
{
    ui->setupUi(this);


    //set spinBox color
    QPalette pal(QColor(255,0,0));
    pal.setColor(QPalette::Background,QColor(255,255,255));
    ui->spinBox->setPalette(pal);


    QPalette pa;
    pa.setColor(QPalette::WindowText,Qt::red);
    ui->spinBox->setPalette(pa);


    //SpinBox connect QSlider
    void(QSpinBox:: * spinSignal)(int) = &QSpinBox::valueChanged;
    connect(ui->spinBox,spinSignal,ui->horizontalSlider,&QSlider::setValue);


    connect(ui->horizontalSlider,&QSlider::valueChanged,ui->spinBox,&QSpinBox::setValue);


    //set init value
    ui->spinBox->setValue(99);


    //click to change volumn
    connect(ui->spinBox,spinSignal,this,[=](){
        int val = ui->spinBox->value();
        QString str = QString::number(val);
        QString setVolume = "amixer set Master "+str+"%";
        qDebug() <         const char* strChar = setVolume.toLatin1();
        system(strChar);
    });
}


smallwidget::~smallwidget()
{
    delete ui;
}

• 
  
  

• 下一曲
  
  

//next一曲
    //buf = QString(MoveNext());
    connect(ui->pushButton_4,&QPushButton::clicked,this,[=](){


        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }


        //get filename
        buf = QString(MoveNext());
        onbuf = buf;
        //kill singing song
        system("killall -9 madplay");
        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";
        const char* strChar = str.toLatin1();


        system(strChar);
        //qDebug() << "bofangyinyue xiayishou" <         //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);


        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);




    });
随机播放键



//set button_7 random play
    connect(ui->pushButton_7,&QPushButton::clicked,this,[=](){
        //judge error by songNum
        if(songNum == 0)
        {
            QMessageBox::critical(this,"critical","no songs in songList");
            return ;
        }
        system("killall -9 madplay");




        //set randInt
        int randInt = rand()%10+1;




        for(int i = 0 ;i         {
            current = current->next;
        }
        if(current == head)
            current = current->next;
        buf = current->path;


        onbuf = buf;


        QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);
        ui->lineEdit->setText(RealfileName);
        QString str =  "madplay "+buf+" &";


        const char* strChar = str.toLatin1();


        system(strChar);
        //show lyric
        QString lyricfile = buf.mid(0,buf.lastIndexOf('.'));
        lyricfile = lyricfile+".txt";


        //open lyricfile and show lyric
        QFile file(lyricfile);
        file.open(QIODevice::ReadOnly);
        QByteArray arr;
        arr = file.readAll();
        ui->textEdit->setText(arr);




        //change label Image
        int num2 = buf.lastIndexOf('/');


        QString pictureName = buf.mid(num2,-1);
        pictureName = pictureName.mid(0,pictureName.lastIndexOf('.'));
        QString pictureName2 =":Image"+pictureName+ "1.jpg";
        pictureName =":Image"+pictureName+ ".jpg";






        //reset widget background
        QPalette palette;
        this->setAutoFillBackground(true);
        QPixmap pixmap;
        pixmap.load(pictureName);
        palette.setBrush(QPalette::Background,QBrush(pixmap));
        palette.setBrush(this->backgroundRole(),QBrush(pixmap.scaled(1118,615).scaled(1118,615,Qt::IgnoreAspectRatio,Qt::SmoothTransformation)));
        QPainter p3(&pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_Source);
        p3.drawPixmap(0, 0, pixmap);
        p3.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        this->setPalette(palette);


        //添加标签中的图片
        QMovie *myMovie6 = new QMovie(pictureName2);
        ui->label_4->setMovie(myMovie6);
        ui->label_4->setScaledContents(true);
        myMovie6->start();


        //set opacity
        QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
        opacityEffect2->setOpacity(0);
        ui->label_6->setGraphicsEffect(opacityEffect2);


    });

• 添加歌曲文件
  
  

void Widget::on_pushButton_5_clicked()
{


    //select song
    QFileDialog *fdlg = nullptr;
    QString fileName = fdlg->getOpenFileName(this,"open File","/home/itcast/Desktop","(*.mp3)");
    if(fileName == NULL)
        return;
    QString RealfileName = fileName.mid(fileName.lastIndexOf('/')+1);
   
    buf = fileName;
   
    //song add to List
    const char* rfn = RealfileName.toLatin1();
    const char* fn = fileName.toLatin1();
    printf("%s %sn",rfn,fn);
    bool flag = AddNode(rfn,fn);


    if(flag)
    {
        //add to QListWigetItem
        QListWidgetItem *item = new QListWidgetItem(QIcon(":Image/To-like.png"),RealfileName);
        ui->listWidget->addItem(item);
        item->setTextAlignment(Qt::AlignLeft);


        QString number = QString::number(songNum);
        ui->lineEdit_2->setText(number);
    }else{
        QMessageBox::critical(this,"error","overlap exists");
    }


}

• 点击ListWidgetItem进行歌曲切换
  
  

void Widget::on_listWidget_itemClicked(QListWidgetItem *item)
{
    buf = item->text();
    buf = "/home/itcast/Desktop/"+buf;


    //change current
    while(current->path != buf)
    {
        current = current->next;
    }
}

• 删除歌曲键
  
  

void Widget::on_pushButton_6_clicked()
{
    if(songNum == 0)
    {
        QMessageBox::critical(this,"critical","no songs in songList");
        return ;
    }
    QString RealfileName = buf.mid(buf.lastIndexOf('/')+1);


    //foreach to find song to delete
    for(int i=0 ;i     {
        if(ui->listWidget->item(i)->text() == RealfileName)
        {
            ui->listWidget->takeItem(i);
            songNum--;


            //updata songNum
            QString number = QString::number(songNum);
            ui->lineEdit_2->setText(number);


            RemoveNode(RealfileName);
            QString filename = "/home/itcast/Desktop/"+RealfileName;
            if(onbuf == filename)
            {
                system("killall -9 madplay");


                //reset picture in label_4
                QMovie *myMovie = new QMovie(":Image/CD.png");
                ui->label_4->setMovie(myMovie);
                ui->label_4->setScaledContents(true);
                myMovie->start();


                ui->lineEdit->setText("");
                ui->textEdit->setText("");
                //reset widget background
                QPalette palette;
                this->setAutoFillBackground(true);
                QPixmap pixmap;
                pixmap.load(":Image/default.jpg");
                palette.setBrush(QPalette::Background,QBrush(pixmap));
                this->setPalette(palette);


                //set opacity
                QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
                opacityEffect2->setOpacity(1);
                ui->label_6->setGraphicsEffect(opacityEffect2);


            }
        }
    }
}

• 音量条
  
  

smallwidget.h

#ifndef SMALLWIDGET_H
#define SMALLWIDGET_H


#include
#include
#include


namespace Ui {
class smallwidget;
}


class smallwidget : public QWidget
{
    Q_OBJECT


public:
    explicit smallwidget(QWidget *parent = nullptr);
    ~smallwidget();


private slots:
    //void on_spinBox_valueChanged(const QString &arg1);
    //void keyPressEvent( QKeyEvent *k );


private:
    Ui::smallwidget *ui;
};
smallwidget.cpp

#include "smallwidget.h"
#include "ui_smallwidget.h"


smallwidget::smallwidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::smallwidget)
{
    ui->setupUi(this);


    //set spinBox color
    QPalette pal(QColor(255,0,0));
    pal.setColor(QPalette::Background,QColor(255,255,255));
    ui->spinBox->setPalette(pal);


    QPalette pa;
    pa.setColor(QPalette::WindowText,Qt::red);
    ui->spinBox->setPalette(pa);


    //SpinBox connect QSlider
    void(QSpinBox:: * spinSignal)(int) = &QSpinBox::valueChanged;
    connect(ui->spinBox,spinSignal,ui->horizontalSlider,&QSlider::setValue);


    connect(ui->horizontalSlider,&QSlider::valueChanged,ui->spinBox,&QSpinBox::setValue);


    //set init value
    ui->spinBox->setValue(99);


    //click to change volumn
    connect(ui->spinBox,spinSignal,this,[=](){
        int val = ui->spinBox->value();
        QString str = QString::number(val);
        QString setVolume = "amixer set Master "+str+"%";
        qDebug() <         const char* strChar = setVolume.toLatin1();
        system(strChar);
    });
}


smallwidget::~smallwidget()
{
    delete ui;
}

• 
  
  

举报

• 设置背景图片、字体大小和颜色、透明度等
  
  

//set font style
    //set Size
    ui->label_2->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->label_5->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->label_6->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->label->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->label_3->setFont(QFont( "Timers" , 12 ,  QFont::Bold));




    //set Color
    QPalette pa;
    pa.setColor(QPalette::WindowText,Qt::red);
    QPalette pa1;
    pa1.setColor(QPalette::WindowText,Qt::yellow);
    ui->label_2->setPalette(pa);
    ui->label_5->setPalette(pa);
    ui->label_3->setPalette(pa);
    ui->label_6->setPalette(pa1);
    ui->label->setPalette(pa);
    ui->label_10->setPalette(pa);


    //set button
    QIcon icon(":/Image/pause2.png");
    ui->pushButton->setIcon(icon);
    ui->pushButton_2->setIcon(QIcon(":Image/play2.png"));
    ui->pushButton_3->setIcon(QIcon(":Image/pre2.png"));
    ui->pushButton_4->setIcon(QIcon(":Image/next2.png"));
    ui->pushButton_5->setIcon(QIcon(":Image/addFromLocal.png"));
    ui->pushButton_6->setIcon(QIcon(":Image/clear.png"));
    ui->pushButton_7->setIcon(QIcon(":Image/random2.png"));
    ui->pushButton->setFlat(true);
    ui->pushButton_2->setFlat(true);
    ui->pushButton_3->setFlat(true);
    ui->pushButton_4->setFlat(true);
    ui->pushButton_5->setFlat(true);
    ui->pushButton_6->setFlat(true);
    ui->pushButton_7->setFlat(true);


    //add filename
    QListWidgetItem *item = new QListWidgetItem(QIcon(":Image/music_list.png"),"music list:");
    ui->listWidget->addItem(item);
    item->setTextAlignment(Qt::AlignLeft);
    ui->listWidget->setStyleSheet("background-color:transparent");


//    QString path = "/home/itcast/Desktop/";
//    QString str1 = "1.mp3";
//    QListWidgetItem *item1 = new QListWidgetItem(str1);
//    ui->listWidget->addItem(item1);
//    item1->setTextAlignment(Qt::AlignLeft);


    //添加标签中的图片
    QMovie *myMovie = new QMovie(":Image/CD.png");
    ui->label_4->setMovie(myMovie);
    ui->label_4->setScaledContents(true);
    myMovie->start();


    //set transparency
    QGraphicsOpacityEffect* opacityEffect2 = new QGraphicsOpacityEffect;
    opacityEffect2->setOpacity(0.75);
    ui->label_4->setGraphicsEffect(opacityEffect2);
    //this->setAttribute(Qt::WA_TranslucentBackground);


    QMovie *myMovie2 = new QMovie(":Image/music-playing.png");
    ui->label_7->setMovie(myMovie2);
    ui->label_7->setScaledContents(true);
    myMovie2->start();


    QMovie *myMovie3 = new QMovie(":Image/systemTrayIcon.png");
    ui->label_8->setMovie(myMovie3);
    ui->label_8->setScaledContents(true);
    myMovie3->start();


//set lineEdit style
    ui->lineEdit->setStyleSheet("background-color:transparent");
    ui->lineEdit_2->setStyleSheet("background-color:transparent");
    QPalette palette;
    palette.setColor(QPalette::Text,Qt::red);
    ui->lineEdit->setPalette(palette);
    ui->lineEdit_2->setPalette(palette);
    ui->lineEdit->setFont(QFont( "Timers" , 12 ,  QFont::Bold) );
    ui->lineEdit_2->setFont(QFont( "Timers" , 12 ,  QFont::Bold));


    //set textEdit style
    ui->textEdit->setStyleSheet("background-color:transparent");


    //set Widget image
    this->setAutoFillBackground(true);
    QPixmap pixmap;
    pixmap.load(":Image/default.jpg");
    palette.setBrush(QPalette::Background,QBrush(pixmap));
    this->setPalette(palette);




    //set listWidget font
    ui->listWidget->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->listWidget->setPalette(palette);


    //set textEdit font
    ui->textEdit->setFont(QFont( "Timers" , 12 ,  QFont::Bold));
    ui->textEdit->setTextColor(Qt::yellow);


    //set textEdit center
    ui->textEdit->setAlignment( Qt::AlignCenter );
7.遇到的问题

• 使用在Widget.h的slot中添加的槽函数进行按键的功能书写时，一个函数中两个system无法运行，尝试了让程序睡1秒，也没有解决，最后使用在connect函数中使用lambda表达式书写匿名函数得以实现功能，但这种写法会使代码变得逻辑不清，虽然已成功实现但不推荐这么写
  
• 使用madplay的参数实现进度条功能，未能实现，madplay的参数没有折腾清楚，最后仅剩不到一天的时间才开始看manpage导致时间不够用，而且我现有的编码水平还有差距
  
• Qt环境搭建的问题，在Linux下安装Qt，去官网下载.run的安装包即可，安装过后运行空界面会报错，直接百度这个错误即可得到解决方案，Ubuntu下是需要apt-get install 两个东西，具体是什么有些忘了
  
• 控件设置透明度的问题，折腾了半天，现在还是不清楚，我的做法是不同的控件用的不同的方法，有Platte、QGraphicsOpacityEffect、setFlat(true)三种，具体有关透明度的设置还需要后面去尝试和学习
  
• 文件名加了空格会出错，有中文会出错，因为不知道如何解决，所以暂时规避了空格（这个问题应该是要迎面解决的！），听我的同学说是要在system函数中使用单引号即可，具体成功与否以后尝试
  
• 背景图片的选取，要和主widget的大小匹配，不匹配的话会很模糊，同时要注意让图片适应屏幕大小，具体如何设置我也是百度查到的，上面代码中有
  
  

8.总结

刚开始拿到这个题目，只自学了两天Qt的我是懵的，但是能怎么办呢，不闷头干就没有课设成绩，那就干呗！
有问题多思考，多百度，总会有很大的提升，祝看这篇文章的网友们也能写出漂亮的图形化！！！