問題

在android中有時候我們需要對螢幕進行截圖操作，單一的截圖操作好解決可以通過activity的頂層view DecorView獲取一個bitmap，得到就是當前activity上面的全部檢視。

 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中包含一些視訊播放器比如SurfaceView GLSurfaceView
TextureView，在呼叫截圖程式碼會發現播放視訊的部分是黑屏的，原因是這幾種視訊渲染的view通過以上程式碼拿到的是緩衝區不是真正的影象。

解決辦法

android5.0以上系統提供了一個 MediaProjectionManager
類來對手機進行錄屏操作，也支援獲取手機的Image影象的操作，知道了這些我們就可以通過提供的api來進行截圖操作了。

這裡通過Service來操作截圖和錄屏的api

1.繫結截圖的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() ? "結束" : "開始");
  }
 

2.請求許可權 onActivityResult 方法中回撥。

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

  成功後
  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         if (requestCode == RECORD_REQUEST_CODE && resultCode == RESULT_OK) {

             //######## 截圖邏輯 ########
             mediaProjection = projectionManager.getMediaProjection(resultCode, data);
             recordService.setMediaProject(mediaProjection);
             recordService.initImageReader();

         }
  }
 

3. 獲取截圖

  @Override
  public void onClick(View view) {

    //########  截圖邏輯 ########
     Bitmap bitmap = recordService.getBitmap();
     mImageView.setImageBitmap(bitmap);
  }

錄屏

錄屏需要初始化一些錄屏引數，輸入麥克風型別視訊型別，儲存路徑等

 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();
         }
 }

開始錄屏

  mediaRecorder.start();

儲存路徑

完整Service程式碼

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;

 @Override
 public IBinder onBind(Intent intent) {
     return new RecordBinder();
 }


 @Override
 public void onCreate() {
     super.onCreate();
     running = false;
     mediaRecorder = new MediaRecorder();
 }


 @Override
 public int onStartCommand(Intent intent, int flags, int startId) {
     return super.onStartCommand(intent, flags, startId);
 }


 @Override
 public 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;
 }


 /**
  * 開始錄屏
  *
  * @return true
  */
 public boolean startRecord() {
     if (mediaProjection == null || running) {
         return false;
     }
     initRecorder();
     createVirtualDisplay();
     mediaRecorder.start();
     running = true;
     return true;
 }


 /**
  * 結束錄屏
  *
  * @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引數
  */
 public void initImageReader() {
     if (mImageReader == null) {
         int maxImages = 2;
         mImageReader = ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, maxImages);
         createImageVirtualDisplay();
     }
 }


 /**
  * 建立一個錄屏 Virtual
  */

 private void createVirtualDisplay() {
     virtualDisplay = mediaProjection
             .createVirtualDisplay("mediaprojection", width, height, dpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mediaRecorder
                     .getSurface(), null, null);
 }


 /**
  * 建立一個ImageReader Virtual
  */
 private void createImageVirtualDisplay() {
     virtualDisplay = mediaProjection
             .createVirtualDisplay("mediaprojection", width, height, dpi,
                     DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mImageReader
                     .getSurface(), null, null);
 }


 /**
  * 初始化儲存螢幕錄影的引數
  */
 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();
     }
 }


 /**
  * 獲取一個儲存螢幕錄影的路徑
  *
  * @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;
     }
 }


 /**
  * 請求完許可權後馬上獲取有可能為null，可以通過判斷is null來重複獲取。
  */
 public Bitmap getBitmap() {
     Bitmap bitmap = cutoutFrame();
     if (bitmap == null) {
         getBitmap();
     }
     return bitmap;
 }


 /**
  * 通過底層來獲取下一幀的影象
  *
  * @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下載