测试C#调用Aplayer播放视频（3：编写简易播放器）

  学习了参考文献1中的示例代码，也找出了前一篇文章中自己测试控件但无法播放视频的问题（没有将解码库文件复制到可执行程序所在的codecs文件夹内），本文基于APlayer组件编写简单的视频播放器，主要实现以下功能：

序号	功能	说明
1	自定义logo	调用SetCustomLogo函数设置未播放视频时的显示图片，图片来自参考文献2
2	打开文件	调用Open函数打开并播放视频文件
3	定时刷新播放信息	参照参考文献1中的demo，使用定时器定时刷新当前播放进度，调用GetDuration获取视频总时长，调用GetPosition获取当前播放时间，同时在OnOpenSucceeded中启动定时器，在OnStateChanged事件中停止定时器
4	暂停/播放/停止	调用Pause/Play/Close函数暂停/播放/停止视频
5	设置音量	调用SetVolume设置音量，尽在0-100范围内调节音量，并未使用APlayer的10倍放大
6	拖拽时间条	调用SetPosition函数在Trackbar的Scroll事件中重新设置播放时间
7	快进/快退	调用SetPosition函数快进/快退10秒

  最后是程序界面、播放视频截图及主要代码：

public Form1()
{
   this.axPlayer1.SetCustomLogo(((Bitmap)Bitmap.FromFile("gundam.jpg")).GetHbitmap().ToInt32());
   axPlayer1.OnOpenSucceeded += new EventHandler(OnOpenSucceeded);
   axPlayer1.OnStateChanged += new _IPlayerEvents_OnStateChangedEventHandler(OnStateChanged);
}

string TimeToString(TimeSpan span)
{
   return span.Hours.ToString("00") + ":" +
   span.Minutes.ToString("00") + ":" +
   span.Seconds.ToString("00");
}

void OnOpenSucceeded(object sender, EventArgs e)
{
   lblProgress.Text= "00:00:00/"+TimeToString(TimeSpan.FromMilliseconds(axPlayer1.GetDuration()));            
   tbTimeline.Maximum = axPlayer1.GetDuration();
   timer1.Start();
}

private void UpdatePlayInfo(object sender, EventArgs e)
{
   lblProgress.Text = TimeToString(TimeSpan.FromMilliseconds(axPlayer1.GetPosition()))+"/" + TimeToString(TimeSpan.FromMilliseconds(axPlayer1.GetDuration()));
   tbTimeline.Value = axPlayer1.GetPosition() < 0 ? 0 : axPlayer1.GetPosition();
}

private void tbVolumn_ValueChanged(object sender, EventArgs e)
{
   axPlayer1.SetVolume(tbVolumn.Value);
}

private void btnForward_Click(object sender, EventArgs e)
{
   axPlayer1.SetPosition(axPlayer1.GetPosition() + 10000);
}

private void btnBack_Click(object sender, EventArgs e)
{
   int timeLine = axPlayer1.GetPosition() - 10000;
   axPlayer1.SetPosition(timeLine < 0 ? 0 : timeLine);
}

private void btnClose_Click(object sender, EventArgs e)
{
   axPlayer1.Close();
}

private void btnPlay_Click(object sender, EventArgs e)
{
   axPlayer1.Play();
}

private void btnPause_Click(object sender, EventArgs e)
{
   axPlayer1.Pause();
}

void OnStateChanged(object sender, _IPlayerEvents_OnStateChangedEvent e)
{
   switch (e.nNewState)
   {
       case 0:
           tbTimeline.Value = 0;
           lblProgress.Text = "00:00:00/00:00:00" ;   
           timer1.Stop();
           break;                
   }
}

private void btnOpen_Click(object sender, EventArgs e)
{
   using (OpenFileDialog ofd = new OpenFileDialog())
   {
       ofd.Filter = "mp4|*.mp4|avi|*.avi|rm|*.rm|rmvb|*.rmvb|flv|*.flv|xr|*.xr|所有文件|*.*";
       ofd.Multiselect = false;
       if (ofd.ShowDialog() == DialogResult.OK)
       {
           axPlayer1.Open(ofd.FileName);
       }
   }
}

private void tbTimeline_Scroll(object sender, EventArgs e)
{
   axPlayer1.SetPosition(tbTimeline.Value);
   lblProgress.Text = TimeToString(TimeSpan.FromMilliseconds(axPlayer1.GetPosition())) + "/" + TimeToString(TimeSpan.FromMilliseconds(axPlayer1.GetDuration()));
}

参考文献：
[1]https://blog.csdn.net/qq_45533937/article/details/115800927
[2]https://www.hpoi.net/hobby/10836