适配了Android5.0以上的截图方法，实现了后台连续截图；使用该方法请求授权同意后开始截图：

private MediaProjectionManager mMediaProjectionManager;
  public void getMediaProjectionManger() {
        mMediaProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
        if (mMediaProjectionManager != null) {
            startActivityForResult(mMediaProjectionManager.createScreenCaptureIntent(), RECORD_REQUEST_CODE);
        }
    }

由于targetSdkVersion 29及以上要求getMediaProjection需要再前台服务执行，所以在onActivityResult里面启动服务：

 @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RECORD_REQUEST_CODE && resultCode == RESULT_OK) {
            Intent intent = new Intent(ZkScreenshotActivity.this, ZkA5AboveScreenshotService.class);
            intent.putExtra("code",resultCode);
            intent.putExtra("data",data);
            ZkUtlis.startService(ZkScreenshotActivity.this,intent);
        }
    }

Service方法如下：

 public class ZkA5AboveScreenshotService extends Service {

    private String mTag = "ZkA5AboveScreenshotService";

    private int mResultCode;

    private Intent mResultData;

    private MediaProjection mMediaProjection;

    private MediaProjectionManager mMediaProjectionManager;

    private int mWidth;

    private int mHeight;

    private int mDensity;

    private ImageReader mImageReader;

    private int mImagesProduced;

    private int mCount = 0;

    @Override
    public void onCreate() {
        super.onCreate();
        mMediaProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        createNotificationChannel();
        mResultCode = intent.getIntExtra("code", -1);
        mResultData = intent.getParcelableExtra("data");
        mMediaProjection = mMediaProjectionManager.getMediaProjection(mResultCode, Objects.requireNonNull(mResultData));
        Log.d(mTag, "mMediaProjection created: " + mMediaProjection);
        startCaptureReader();
        return super.onStartCommand(intent, flags, startId);
    }

    /**
     * startCaptureReader
     */
    @SuppressLint("WrongConstant")
    private void startCaptureReader() {
        WindowManager wm = (WindowManager) getBaseContext().getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        Point size = new Point();
        display.getSize(size);
        mWidth = size.x;
        mHeight = size.y;
        Log.d(mTag,"width:" + mWidth + "   height：" + mHeight);
        DisplayMetrics metrics = getResources().getDisplayMetrics();
        mDensity = metrics.densityDpi;
        // start capture reader
        mImageReader = ImageReader.newInstance(mWidth, mHeight, 0x01, 2);
        mMediaProjection.createVirtualDisplay("screencap", mWidth, mHeight, mDensity, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mImageReader.getSurface(), null, null);
        mImageReader.setOnImageAvailableListener(new ImageAvailableListener(), null);
    }

    /**
     * ImageAvailableListener
     */
    private class ImageAvailableListener implements ImageReader.OnImageAvailableListener {
        @Override
        public void onImageAvailable(ImageReader reader) {
            try (Image image = reader.acquireLatestImage()) {
                if (image != null) {
                      /**
                       * 截图结果，会在内容更新自动回调，该方法可以实现连续截图，无需重复启用截图方法
                       */

                    }
                    image.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Create Notification Channel
     */
    private void createNotificationChannel() {
        //获取一个Notification构造器
        Notification.Builder builder = new Notification.Builder(this.getApplicationContext());
        //点击后跳转的界面，可以设置跳转数据
        Intent nfIntent = new Intent(this, ZkScreenshotActivity.class);
        // 设置PendingIntent
        builder.setContentIntent(PendingIntent.getActivity(this, 0, nfIntent, 0))
                // 设置下拉列表中的图标(大图标)
                .setLargeIcon(BitmapFactory.decodeResource(this.getResources(), R.mipmap.ic_launcher))
                // 设置下拉列表里的标题
                //.setContentTitle("SMI InstantView")
                // 设置状态栏内的小图标
                .setSmallIcon(R.mipmap.ic_launcher)
                // 设置上下文内容
                .setContentText("is running......")
                // 设置该通知发生的时间
                .setWhen(System.currentTimeMillis());

        /*以下是对Android 8.0的适配*/
        //普通notification适配
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            builder.setChannelId("notification_id");
        }
        //前台服务notification适配
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationManager notificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
            NotificationChannel channel = new NotificationChannel("notification_id", "notification_name", NotificationManager.IMPORTANCE_LOW);
            notificationManager.createNotificationChannel(channel);
        }
        // 获取构建好的Notification
        Notification notification = builder.build();
        //设置为默认的声音
        notification.defaults = Notification.DEFAULT_SOUND;
        startForeground(110, notification);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d(mTag, "Service onDestroy");
        if (mImageReader != null) {
            mImageReader.setOnImageAvailableListener(null,null);
            mImageReader.close();
            mImageReader = null;
        }
        if (mMediaProjection != null) {
            mMediaProjection.stop();
            mMediaProjection = null;
        }
        mMediaProjectionManager = null;
    }

下面是将Image转Bitmap

 /**
     * Image 转 Bitmap
     * @param image
     */
    private Bitmap imageToBitmap(Image image) {
        Image.Plane[] planes = image.getPlanes();
        ByteBuffer buffer = planes[0].getBuffer();
        int pixelStride = planes[0].getPixelStride();
        int rowStride = planes[0].getRowStride();
        int rowPadding = rowStride - pixelStride * mWidth;

        Bitmap bitmap = Bitmap.createBitmap(mWidth + rowPadding / pixelStride, mHeight, Bitmap.Config.ARGB_8888);
        bitmap.copyPixelsFromBuffer(buffer);
        return bitmap; 
    }