Android播放视频之VideoView

目前很多app都会有短视频内容，这里就来讲一下android中播放视频的几种方式。

Android播放视频有三种方式：

1，调用系统已有的播放软件播放视频。

2，使用android提供的VideoView控件定制自己的视频播放器。

3，使用MediaPlayer和SurfaceView定制自己的视频播放器。

第一种方式最简单了：

 //调用系统自带的播放器        Uri uri = Uri.parse("/storage/emulated/0/DCIM/Camera/VID_20161103_105921.mp4");        Intent intent = new Intent(Intent.ACTION_VIEW);        intent.setDataAndType(uri, "video/mp4");        startActivity(intent);

就android4.2.2的源码来看，系统自带的播放器程序是Gallery2

/packages/apps/Gallery2

通过清单文件，可以知道处理该intent的activity：

看一下这个MovieActivity.java

 @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);      。。        setContentView(R.layout.movie_view);        View rootView = findViewById(R.id.movie_view_root);        setSystemUiVisibility(rootView);        Intent intent = getIntent();      。。。        mPlayer = new MoviePlayer(rootView, this, intent.getData(), savedInstanceState,                !mFinishOnCompletion) {            @Override            public void onCompletion() {                if (mFinishOnCompletion) {                    finish();                }            }        };

主要用到MoviePlayer，看一下这个MoviePlayer类做了啥

 public MoviePlayer(View rootView, final MovieActivity movieActivity,            Uri videoUri, Bundle savedInstance, boolean canReplay) {        mContext = movieActivity.getApplicationContext();        mRootView = rootView;        mVideoView = (VideoView) rootView.findViewById(R.id.surface_view);        mBookmarker = new Bookmarker(movieActivity);        mUri = videoUri;        mController = new MovieControllerOverlay(mContext);        ((ViewGroup)rootView).addView(mController.getView());        mController.setListener(this);        mController.setCanReplay(canReplay);        mVideoView.setOnErrorListener(this);        mVideoView.setOnCompletionListener(this);        mVideoView.setVideoURI(mUri);        mVideoView.setOnTouchListener(new View.OnTouchListener() {            @Override            public boolean onTouch(View v, MotionEvent event) {                mController.show();                return true;            }        });        // The SurfaceView is transparent before drawing the first frame.        // This makes the UI flashing when open a video. (black -> old screen        // -> video) However, we have no way to know the timing of the first        // frame. So, we hide the VideoView for a while to make sure the        // video has been drawn on it.        mVideoView.postDelayed(new Runnable() {            @Override            public void run() {                mVideoView.setVisibility(View.VISIBLE);

这个mVideoView是VideoView类型

所以通过上面代码可以知道，android自带的播放器也是使用VideoView这个控件来实现的。

那么接着就讲一下第二种方式，使用VideoView定制自己的视频播放器

VideoView看名字应该是View的子类

VideoView的直接父类是SurfaceView .关于SurfaceView前面Android视图SurfaceView的使用一文已做简单介绍。

SurfaceView可以用来显示相机的预览界面，也可以用来显示视频的数据。

下面就来看一下如何使用VideoView。

使用VideoView播放视频也有两种方式：

一种是只使用VideoView进行播放视频，自己自定义播放进度，播放状态的布局，然后自己控制播放

另一种就是VideoView结合MediaController播放视频，这种方式不需要自己写布局去控制播放。

下面先看第一方式：

结合代码和效果图一起分析下是如何实现播放视频的：

用手机拍摄了一段视频，然后用写的应用程序来播放这段视频（真机测试的）

启动应用看到界面如上：

看一下布局文件：

<?xml version="1.0" encoding="utf-8"?>

MyVideoView是用来播放视频的，ImageView是用来显示视频的缩略图的（还未开始播放，先显示缩略图，覆盖VideoView那块区域，因为一开始VideoView那块区域是黑色的），cover （FrameLayout）是用来控制 CheckBox 和 LinearLayout 隐藏与显示，CheckBox是控制播放与停止，LinearLayout就是显示播放进度的布局，两个TextView分别是显示当前播放的时间和总时间，SeekBar就是显示进度，可以拖曳到任意位置播放。

下面的代码片段就是设置视频预览图片

 private void initVideoView() {        Log.d(TAG,"initVideoView ");        Bitmap bitmap = ThumbnailUtils.createVideoThumbnail(PATH, MINI_KIND);        if(bitmap != null){            preview.setImageBitmap(bitmap);        }        videoView.setVideoURI(Uri.parse(PATH));    }

这里用到了ThumbnailUtils这个工具，参考官方文档：https://developer.android.com/reference/android/media/ThumbnailUtils.html

VideoView播放视频，需要传入视频资源，传入方式有以下几种：

关于VideoView官方文档：https://developer.android.com/reference/android/widget/VideoView.html

我这里播放本地视频，当然也可以播放网络视频。

点击CheckBox进行播放，看一下播放效果：

看一下代码：

 playOrPause.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {                Log.d(TAG,"onCheckedChanged  isChecked="+isChecked);                if(isChecked){//暂停                    videoView.pause();                    positon = videoView.getCurrentPosition();                }else{//播放                    videoView.seekTo(positon);                    videoView.start();                    playOrPause.setVisibility(View.GONE);                    preview.setVisibility(View.GONE);                }            }        });

播放视频的话直接调用VideoView 的start()函数即可，seekTo（）函数设置从哪个位置开始播放。

pasue（）暂停播放，getCurrentPosition（）获取播放到哪个位置了时间毫秒。

看一下控制播放进度消息的代码：

@Override    public void onClick(View v) {        switch (v.getId()){            case R.id.cover:                Log.d(TAG,"click cover ");                int currentPosition = videoView.getCurrentPosition();                int duration = videoView.getDuration();                Log.d(TAG,"currentPosition = "+currentPosition+"duration = "+duration);                if(currentPosition>0){//说明已经播放了，不管现在是暂停还是播放中                    if(playOrPause.getVisibility() == View.VISIBLE){                        playOrPause.setVisibility(View.GONE);                    }else {                        playOrPause.setVisibility(View.VISIBLE);                    }                    if(progressLayout.getVisibility() == View.VISIBLE){                        myHandler.removeCallbacks(runnable);                        progressLayout.setVisibility(View.GONE);                    }else {                        progressLayout.setVisibility(View.VISIBLE);                        currentTime.setText((currentPosition/1000)/60%60/10+""+(currentPosition/1000)/60%60%10+":"                                +(currentPosition/1000)%60/10+""+(currentPosition/1000)%60%10);                        sumTime.setText((duration/1000)/60%60/10+""+(duration/1000)/60%60%10+":"                                +(duration/1000)%60/10+""+(duration/1000)%60%10);                        progressBar.setMax(duration);                        progressBar.setProgress(currentPosition);                        new Thread(new Runnable() {                            @Override                            public void run() {                                while(progressLayout.getVisibility()==View.VISIBLE){                                    myHandler.sendEmptyMessage(0);                                    try {                                        Thread.sleep(1000);                                    } catch (InterruptedException e) {                                        e.printStackTrace();                                    }                                }                            }                        }).start();                        myHandler.postDelayed(runnable,3000);                    }                }                break;            default:                break;        }    }    private Runnable runnable = new Runnable() {        @Override        public void run() {            playOrPause.setVisibility(View.GONE);            progressLayout.setVisibility(View.GONE);        }    };

下载该demo源码点击这里

接着看一下VideoView结合MediaController来播放视频，就简单几句代码就可以了：

  videoView = (MyVideoView) findViewById(R.id.video_view);        videoView.setVideoURI(Uri.parse(PATH));        MediaController mediaController = new MediaController(this);        videoView.setMediaController(mediaController);

布局文件

<?xml version="1.0" encoding="utf-8"?>

效果图如下：

可以直接控制视频的播放了。

这里来简单看一下VideoView的源码。

源码位置：frameworks/base/core/java/android/widget/VideoView.java

public VideoView(Context context, AttributeSet attrs) {        this(context, attrs, 0);        initVideoView();    }

private void initVideoView() {        mVideoWidth = 0;        mVideoHeight = 0;        getHolder().addCallback(mSHCallback);        getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);        setFocusable(true);        setFocusableInTouchMode(true);        requestFocus();        mCurrentState = STATE_IDLE;        mTargetState  = STATE_IDLE;    }

  public void setVideoURI(Uri uri) {        setVideoURI(uri, null);    }

 public void setVideoURI(Uri uri, Map headers) {        mUri = uri;        mHeaders = headers;        mSeekWhenPrepared = 0;        openVideo();        requestLayout();        invalidate();    }

private void openVideo() {        if (mUri == null || mSurfaceHolder == null) {            // not ready for playback just yet, will try again later            return;        }        // Tell the music playback service to pause        // TODO: these constants need to be published somewhere in the framework.        Intent i = new Intent("com.android.music.musicservicecommand");        i.putExtra("command", "pause");        mContext.sendBroadcast(i);        // we shouldn't clear the target state, because somebody might have        // called start() previously        release(false);        try {            mMediaPlayer = new MediaPlayer();            mMediaPlayer.setOnPreparedListener(mPreparedListener);            mMediaPlayer.setOnVideoSizeChangedListener(mSizeChangedListener);            mMediaPlayer.setOnCompletionListener(mCompletionListener);            mMediaPlayer.setOnErrorListener(mErrorListener);            mMediaPlayer.setOnInfoListener(mOnInfoListener);            mMediaPlayer.setOnBufferingUpdateListener(mBufferingUpdateListener);            mCurrentBufferPercentage = 0;            mMediaPlayer.setDataSource(mContext, mUri, mHeaders);            mMediaPlayer.setDisplay(mSurfaceHolder);            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);            mMediaPlayer.setScreenOnWhilePlaying(true);            mMediaPlayer.prepareAsync();            // we don't set the target state here either, but preserve the            // target state that was there before.            mCurrentState = STATE_PREPARING;            attachMediaController();        } catch (IOException ex) {            Log.w(TAG, "Unable to open content: " + mUri, ex);            mCurrentState = STATE_ERROR;            mTargetState = STATE_ERROR;            mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);            return;        } catch (IllegalArgumentException ex) {            Log.w(TAG, "Unable to open content: " + mUri, ex);            mCurrentState = STATE_ERROR;            mTargetState = STATE_ERROR;            mErrorListener.onError(mMediaPlayer, MediaPlayer.MEDIA_ERROR_UNKNOWN, 0);            return;        }    }

public void start() {        if (isInPlaybackState()) {            mMediaPlayer.start();            mCurrentState = STATE_PLAYING;        }        mTargetState = STATE_PLAYING;    }

通过上面几个关键的函数可以看出，VideoView播放播放视频是通过SurfaceView(VideoView本身就是SurfaceView)加上MediaPlayer（VideoView封装该类）这个类来实现的。这也是后面要讲的第三种播放视频的方式------------使用MediaPlayer和SurfaceView定制自己的视频播放器。

看一下MediaController这个类

它是一个视图，VideoView通过setMediaController(MediaController controller)函数添加MediaController其实就是添加一个视图，该视图容器里有控件来控制视频的播放

public void setMediaController(MediaController controller) {        if (mMediaController != null) {            mMediaController.hide();        }        mMediaController = controller;        attachMediaController();    }    private void attachMediaController() {        if (mMediaPlayer != null && mMediaController != null) {            mMediaController.setMediaPlayer(this);            View anchorView = this.getParent() instanceof View ?                    (View)this.getParent() : this;            mMediaController.setAnchorView(anchorView);            mMediaController.setEnabled(isInPlaybackState());        }    }

看一下Mediacontroller的源码，路径在frameworks/base/core/java/android/widget/MediaController.java

 public void setAnchorView(View view) {        if (mAnchor != null) {            mAnchor.removeOnLayoutChangeListener(mLayoutChangeListener);        }        mAnchor = view;        if (mAnchor != null) {            mAnchor.addOnLayoutChangeListener(mLayoutChangeListener);        }        FrameLayout.LayoutParams frameParams = new FrameLayout.LayoutParams(                ViewGroup.LayoutParams.MATCH_PARENT,                ViewGroup.LayoutParams.MATCH_PARENT        );        removeAllViews();        View v = makeControllerView();        addView(v, frameParams);    }    /**     * Create the view that holds the widgets that control playback.     * Derived classes can override this to create their own.     * @return The controller view.     * @hide This doesn't work as advertised     */    protected View makeControllerView() {        LayoutInflater inflate = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);        mRoot = inflate.inflate(com.android.internal.R.layout.media_controller, null);        initControllerView(mRoot);        return mRoot;    }

看一下它的布局结构

frameworks/base/core/res/res/layout/media_controller.xml

<?xml version="1.0" encoding="utf-8"?>

上面两个类的源码就没有详细分析了。

关于VideoView播放视频就讲这些了，demo是运行在真机上的。

后面文章讲一下使用MediaPlayer和SurfaceView来播放视频。

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