UI设计流程图

UI设计界面

• 主界面
  

• 控制条
  

• 播放列表
  

• 画面显示
  

• 标题栏
  

• 设置界面
  

• 提示框
  

点击播放功能实现

槽函数实现：
connect(ui->ctrlBarWind, &CtrlBar::SigPlayOrPause, this, &MainWind::OnPlayOrPause);

ctrbar.h

class CtrlBar : public QWidget
{Q_OBJECTpublic:explicit CtrlBar(QWidget *parent = 0);~CtrlBar();
signals:void SigPlayOrPause();      // 先实现这个private slots:void on_playOrPauseBtn_clicked();void on_stopBtn_clicked();private:Ui::CtrlBar *ui;
};

ctrbar.cpp

CtrlBar::CtrlBar(QWidget *parent) :QWidget(parent),ui(new Ui::CtrlBar)
{ui->setupUi(this);
}CtrlBar::~CtrlBar()
{delete ui;
}void CtrlBar::on_playOrPauseBtn_clicked()
{qDebug() << "on_playOrPauseBtn_clicked";emit SigPlayOrPause();      // 发送信号
}

mainwid.h

class MainWind : public QMainWindow
{Q_OBJECTpublic:explicit MainWind(QWidget *parent = 0);~MainWind();int InitSignalsAndSlots();void OnPlayOrPause();
private:Ui::MainWind *ui;IjkMediaPlayer *mp_ = NULL;
};

mainwind.cpp

MainWind::MainWind(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWind)
{ui->setupUi(this);// 初始化信号槽相关的InitSignalsAndSlots();
}MainWind::~MainWind()
{delete ui;
}int MainWind::InitSignalsAndSlots()
{connect(ui->ctrlBarWind, &CtrlBar::SigPlayOrPause, this, &MainWind::OnPlayOrPause);
}int MainWind::message_loop(void *arg)
{IjkMediaPlayer *mp = (IjkMediaPlayer *)arg;while (1) {AVMessage msg;int retval = mp->ijkmp_get_msg(&msg, 1);    if (retval < 0)break;switch (msg.what) {case FFP_MSG_PREPARED:mp->ijkmp_start();break;default:break;}msg_free_res(&msg);
}void MainWind::OnPlayOrPause()
{int ret = 0;// 1. 先检测mp是否已经创建if(!mp_) {mp_ = new IjkMediaPlayer();//1.1 创建ret = mp_->ijkmp_create(std::bind(&MainWind::message_loop, this, std::placeholders::_1));if(ret <0) {delete mp_;mp_ = NULL;return;}// 1.2 设置urlmp_->ijkmp_set_data_source("m1.mp3");// 1.3 准备工作ret = mp_->ijkmp_prepare_async();if(ret <0) {delete mp_;mp_ = NULL;return;}} else {// 已经准备好了，则暂停或者恢复播放}
}