QT ui以绘制好界面实现视频播放，包含开始、暂停、停止按钮和进度条、总时长、播放进度.cpp

以下是一个简单的示例代码，演示如何使用QT UI绘制视频播放器界面，并实现视频播放、暂停、停止等功能：

首先，需要在QT Designer中设计一个界面，包含一个QMediaPlayer控件、开始、暂停、停止按钮、进度条、总时长和当前播放进度等控件。将该界面保存为一个.ui文件，然后使用uic工具将其转换为C++代码。

ui文件代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>VideoPlayer</class>
 <widget class="QWidget" name="VideoPlayer">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Video Player</string>
  </property>
  <layout class="QVBoxLayout" name="verticalLayout">
   <item>
    <widget class="QMediaPlayer" name="mediaPlayer"/>
   </item>
   <item>
    <widget class="QSlider" name="progressSlider">
     <property name="orientation">
      <enum>Qt::Horizontal</enum>
     </property>
    </widget>
   </item>
   <item>
    <layout class="QHBoxLayout" name="horizontalLayout">
     <item>
      <widget class="QPushButton" name="playButton">
       <property name="text">
        <string>Play</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QPushButton" name="pauseButton">
       <property name="text">
        <string>Pause</string>
       </property>
      </widget>
     </item>
     <item>
      <widget class="QPushButton" name="stopButton">
       <property name="text">
        <string>Stop</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
   <item>
    <layout class="QHBoxLayout" name="horizontalLayout_2">
     <item>
      <widget class="QLabel" name="durationLabel">
       <property name="text">
        <string>00:00:00 / 00:00:00</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <resources/>
 <connections/>
</ui>

转换后的C++代码如下：

#include "ui_VideoPlayer.h"
#include <QMediaPlayer>
#include <QFileDialog>
#include <QBoxLayout>
#include <QLabel>
#include <QSlider>
#include <QPushButton>
#include <QTime>

class VideoPlayer : public QWidget
{
    Q_OBJECT

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

private slots:
    void openFile();
    void play();
    void pause();
    void stop();
    void updateDuration(qint64 duration);
    void updatePosition(qint64 position);

private:
    Ui::VideoPlayer ui;
    QMediaPlayer *m_player;
    QLabel *m_durationLabel;
    QSlider *m_progressSlider;
};

VideoPlayer::VideoPlayer(QWidget *parent) :
    QWidget(parent),
    m_player(new QMediaPlayer(this)),
    m_durationLabel(new QLabel(this)),
    m_progressSlider(new QSlider(Qt::Horizontal, this))
{
    ui.setupUi(this);

    QVBoxLayout *layout = new QVBoxLayout;
    layout->addWidget(ui.mediaPlayer);
    layout->addWidget(m_progressSlider);

    QHBoxLayout *buttonLayout = new QHBoxLayout;
    QPushButton *openButton = new QPushButton(tr("Open"));
    QPushButton *playButton = new QPushButton(tr("Play"));
    QPushButton *pauseButton = new QPushButton(tr("Pause"));
    QPushButton *stopButton = new QPushButton(tr("Stop"));
    buttonLayout->addWidget(openButton);
    buttonLayout->addWidget(playButton);
    buttonLayout->addWidget(pauseButton);
    buttonLayout->addWidget(stopButton);

    layout->addLayout(buttonLayout);

    QHBoxLayout *labelLayout = new QHBoxLayout;
    labelLayout->addWidget(m_durationLabel);
    layout->addLayout(labelLayout);

    setLayout(layout);

    m_player->setVideoOutput(ui.mediaPlayer);

    connect(openButton, &QPushButton::clicked, this, &VideoPlayer::openFile);
    connect(playButton, &QPushButton::clicked, this, &VideoPlayer::play);
    connect(pauseButton, &QPushButton::clicked, this, &VideoPlayer::pause);
    connect(stopButton, &QPushButton::clicked, this, &VideoPlayer::stop);
    connect(m_progressSlider, &QSlider::sliderMoved, this, [this](int value) {
        m_player->setPosition(value * m_player->duration() / m_progressSlider->maximum());
    });
    connect(m_player, &QMediaPlayer::durationChanged, this, &VideoPlayer::updateDuration);
    connect(m_player, &QMediaPlayer::positionChanged, this, &VideoPlayer::updatePosition);
}

VideoPlayer::~VideoPlayer()
{
}

void VideoPlayer::openFile()
{
    QString fileName = QFileDialog::getOpenFileName(this, tr("Open Video"), ".", tr("Video Files (*.mp4 *.avi *.wmv)"));
    if (!fileName.isEmpty()) {
        m_player->setMedia(QUrl::fromLocalFile(fileName));
        m_player->play();
    }
}

void VideoPlayer::play()
{
    m_player->play();
}

void VideoPlayer::pause()
{
    m_player->pause();
}

void VideoPlayer::stop()
{
    m_player->stop();
}

void VideoPlayer::updateDuration(qint64 duration)
{
    QString durationText = QTime(0, 0).addMSecs(duration).toString("hh:mm:ss");
    m_durationLabel->setText(QString("00:00:00 / %1").arg(durationText));
    m_progressSlider->setMaximum(duration / 1000);
}

void VideoPlayer::updatePosition(qint64 position)
{
    QString positionText = QTime(0, 0).addMSecs(position).toString("hh:mm:ss");
    m_durationLabel->setText(QString("%1 / %2").arg(positionText).arg(m_durationLabel->text().split("/").last()));
    m_progressSlider->setValue(position / 1000);
}

在主函数中创建一个VideoPlayer对象，然后将其显示出来即可：

#include "VideoPlayer.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    VideoPlayer player;
    player.show();
    return a.exec();
}