问题

在android中有时候我们需要对屏幕进行截屏操作，单一的截屏操作好解决可以通过activity的顶层view DecorView获取一个bitmap，得到就是当前activity上面的全部视图。

 View view = activity.getWindow().getDecorView();view.setDrawingCacheEnabled(true);view.buildDrawingCache();Bitmap bmp = view.getDrawingCache();DisplayMetrics dm = new DisplayMetrics();activity.getWindowManager().getDefaultDisplay().getMetrics(dm);Bitmap ret = Bitmap.createBitmap(bmp, 0, 0, dm.widthPixels, dm.heightPixels);view.destroyDrawingCache();

如果activity中包含一些视频播放器比如SurfaceView GLSurfaceView
TextureView，在调用截屏代码会发现播放视频的部分是黑屏的，原因是这几种视频渲染的view通过以上代码拿到的是缓冲区不是真正的图像。

解决办法

android5.0以上系统提供了一个 MediaProjectionManager
类来对手机进行录屏操作，也支持获取手机的Image图像的操作，知道了这些我们就可以通过提供的api来进行截屏操作了。

这里通过Service来操作截屏和录屏的api

1.绑定截屏的Service

 Intent intent = new Intent(this, ScreenService.class);bindService(intent, mServiceConnection, BIND_AUTO_CREATE);public void onServiceConnected(ComponentName className, IBinder service) {DisplayMetrics metrics = new DisplayMetrics();getWindowManager().getDefaultDisplay().getMetrics(metrics);ScreenService.RecordBinder binder = (ScreenService.RecordBinder) service;recordService = binder.getRecordService();recordService.setConfig(metrics.widthPixels, metrics.heightPixels, metrics.densityDpi);mButton.setEnabled(true);mButton.setText(recordService.isRunning() ? "结束" : "开始");}

2.请求权限 onActivityResult 方法中回调。

 Intent captureIntent = projectionManager.createScreenCaptureIntent();startActivityForResult(captureIntent, RECORD_REQUEST_CODE);

  成功后@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {if (requestCode == RECORD_REQUEST_CODE && resultCode == RESULT_OK) {//######## 截屏逻辑 ########mediaProjection = projectionManager.getMediaProjection(resultCode, data);recordService.setMediaProject(mediaProjection);recordService.initImageReader();}}

3. 获取截屏

  @Overridepublic void onClick(View view) {//########  截屏逻辑 ########Bitmap bitmap = recordService.getBitmap();mImageView.setImageBitmap(bitmap);}

录屏

录屏需要初始化一些录屏参数，输入麦克风类型视频类型，保存路径等

 private void initRecorder() {mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);mediaRecorder.setOutputFile(getSavePath() + System.currentTimeMillis() + ".mp4");mediaRecorder.setVideoSize(width, height);mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);mediaRecorder.setVideoEncodingBitRate(5 * 1024 * 1024);mediaRecorder.setVideoFrameRate(30);try {mediaRecorder.prepare();} catch (IOException e) {e.printStackTrace();}}

开始录屏

  mediaRecorder.start();

保存路径

完整Service代码

public class ScreenService extends Service {
private MediaRecorder mediaRecorder;
private VirtualDisplay virtualDisplay;
private boolean running;
private int width = 720;
private int height = 1080;
private int dpi;
private ImageReader mImageReader;
private MediaProjection mediaProjection;

 @Overridepublic IBinder onBind(Intent intent) {return new RecordBinder();}@Overridepublic void onCreate() {super.onCreate();running = false;mediaRecorder = new MediaRecorder();}@Overridepublic int onStartCommand(Intent intent, int flags, int startId) {return super.onStartCommand(intent, flags, startId);}@Overridepublic void onDestroy() {super.onDestroy();}public void setMediaProject(MediaProjection project) {mediaProjection = project;}public boolean isRunning() {return running;}public void setConfig(int width, int height, int dpi) {this.width = width;this.height = height;this.dpi = dpi;}/*** 开始录屏** @return true*/public boolean startRecord() {if (mediaProjection == null || running) {return false;}initRecorder();createVirtualDisplay();mediaRecorder.start();running = true;return true;}/*** 结束录屏** @return true*/public boolean stopRecord() {if (!running) {return false;}running = false;mediaRecorder.stop();mediaRecorder.reset();virtualDisplay.release();mediaProjection.stop();return true;}public void setMediaProjection(MediaProjection mediaProjection) {this.mediaProjection = mediaProjection;}/*** 初始化ImageRead参数*/public void initImageReader() {if (mImageReader == null) {int maxImages = 2;mImageReader = ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, maxImages);createImageVirtualDisplay();}}/*** 创建一个录屏 Virtual*/private void createVirtualDisplay() {virtualDisplay = mediaProjection.createVirtualDisplay("mediaprojection", width, height, dpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mediaRecorder.getSurface(), null, null);}/*** 创建一个ImageReader Virtual*/private void createImageVirtualDisplay() {virtualDisplay = mediaProjection.createVirtualDisplay("mediaprojection", width, height, dpi,DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mImageReader.getSurface(), null, null);}/*** 初始化保存屏幕录像的参数*/private void initRecorder() {mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);mediaRecorder.setOutputFile(getSavePath() + System.currentTimeMillis() + ".mp4");mediaRecorder.setVideoSize(width, height);mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);mediaRecorder.setVideoEncodingBitRate(5 * 1024 * 1024);mediaRecorder.setVideoFrameRate(30);try {mediaRecorder.prepare();} catch (IOException e) {e.printStackTrace();}}/*** 获取一个保存屏幕录像的路径** @return path*/public String getSavePath() {if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {String rootDir = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" +"ScreenRecord" + "/";File file = new File(rootDir);if (!file.exists()) {if (!file.mkdirs()) {return null;}}return rootDir;} else {return null;}}/*** 请求完权限后马上获取有可能为null，可以通过判断is null来重复获取。*/public Bitmap getBitmap() {Bitmap bitmap = cutoutFrame();if (bitmap == null) {getBitmap();}return bitmap;}/*** 通过底层来获取下一帧的图像** @return bitmap*/public Bitmap cutoutFrame() {Image image = mImageReader.acquireLatestImage();if (image == null) {return null;}int width = image.getWidth();int height = image.getHeight();final Image.Plane[] planes = image.getPlanes();final ByteBuffer buffer = planes[0].getBuffer();int pixelStride = planes[0].getPixelStride();int rowStride = planes[0].getRowStride();int rowPadding = rowStride - pixelStride * width;Bitmap bitmap = Bitmap.createBitmap(width +rowPadding / pixelStride, height, Bitmap.Config.ARGB_8888);bitmap.copyPixelsFromBuffer(buffer);return Bitmap.createBitmap(bitmap, 0, 0, width, height);}public class RecordBinder extends Binder {public ScreenService getRecordService() {return ScreenService.this;}}

demo下载

github