Android截图方式

本文总结了安卓实现截图的几种方式。

View.getDrawingCache()

可以实现所有View的截图及全屏幕的截图，但是WebView无法截图。

    @Deprecated
    public static Bitmap createBitmapFromView(View view) {
        Bitmap bitmap;
        view.setDrawingCacheEnabled(true);
        view.buildDrawingCache();
        Bitmap src = view.getDrawingCache();
        bitmap = Bitmap.createBitmap(src, 0, src.getWidth(), src.getHeight());
        view.destroyDrawingCache();
        view.setDrawingCacheEnabled(false);
        src.recycle();
        src = null;
        return bitmap;
    }

View绘制

创建画布传给View进行绘制。

    public static Bitmap createBitmapFromView(View view) {
        if (view == null) {
            return null;
        }
        Bitmap screenshot;
        screenshot = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(screenshot);
        canvas.translate(-view.getScrollX(), -view.getScrollY());
        view.draw(canvas);
        return screenshot;
    }

WebView.capturePicture

针对WebView截图的实现方式

    public static Bitmap captureFromWebView(WebView webView) {
        Picture snapShot = webView.capturePicture();
        Bitmap bmp = Bitmap.createBitmap(snapShot.getWidth(),
                snapShot.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bmp);
        snapShot.draw(canvas);
        return bmp;
    }

SurfaceControl.screenshot

SurfaceControl.screenshot()的低版本是Surface.screenshot()方法，这两种方法都是系统内部提供的截屏函数，但是这个函数是@hide的，所以无法直接调用，需要反射调用。

    public static Bitmap screenshot(Context context) {
        Display display = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
        DisplayMetrics displayMetrics = new DisplayMetrics();
        display.getRealMetrics(displayMetrics);

        String surfaceClassName;
        if (Build.VERSION.SDK_INT <= 17) {
            surfaceClassName = "android.view.Surface";
        } else {
            surfaceClassName = "android.view.SurfaceControl";
        }
        Class<?> classname;
        Bitmap bm = null;
        try {
            classname = Class.forName(surfaceClassName);
            Method method = classname.getDeclaredMethod("screenshot",
                    new Class[]{int.class, int.class});
            bm = (Bitmap) method.invoke(
                    null,
                    new Object[]{Integer.valueOf(displayMetrics.widthPixels),//分辨率
                            Integer.valueOf(displayMetrics.heightPixels)});
        } catch (Exception e) {
            e.printStackTrace();
        }

        return bm;
    }

MediaProjection + ImageReader

Android5.0以上提供了MediaProjection，方便截屏录屏等功能。局限是必须进行申请会话授权。

 public void screenshot(int resultCode, Intent data) {
        final MediaProjection mediaProjection = mManager.getMediaProjection(resultCode, data);
        if (mediaProjection == null) {
            return;
        }

        mVirtualDisplay = mediaProjection.createVirtualDisplay("snap",
                screenWidth, screenHeight, densityDpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC,
                mSurface, null, null);
        Handler handler = new Handler(getMainLooper());
        handler.postDelayed(new Runnable() {
            public void run() {
                //capture the screen
                mImage = mImageReader.acquireLatestImage();
                if (mImage == null) {
                    return;
                }
                int width = mImage.getWidth();
                int height = mImage.getHeight();
                final Image.Plane[] planes = mImage.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);
                bitmap = Bitmap.createBitmap(bitmap, width, height);
                mImage.close();
                
                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy_MM_dd_hh_mm_ss");
                String strDate = dateFormat.format(new java.util.Date());
                String pathImage = Environment.getExternalStorageDirectory().getPath() + "/DCIM/";
                String nameImage = pathImage + strDate + ".png";

                if (bitmap != null) {
                    try {
                        File dir = new File(pathImage);
                        if (!dir.exists() && !dir.mkdirs()) {
                            dir.mkdirs();

                        }
                        File fileImage = new File(nameImage);
                        if (!fileImage.exists() && !fileImage.createNewFile()) {
                            fileImage.createNewFile();
                        }
                        FileOutputStream out = new FileOutputStream(fileImage);
                        if (out != null) {
                            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
                            out.flush();
                            out.close();
                            Intent media = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
                            Uri contentUri = Uri.fromFile(fileImage);
                            media.setData(contentUri);
                            sendBroadcast(media);
                            mediaProjection.stop();
                            finish();
                        }
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        finish();
                    }
                }
            }
        }, 50);
    }

PixelCopy.request

提供发出PixelCopy请求的机制，允许将Surface中的内容复制到Bitmap中。需要API 24（Android 7.0以上）支持。

    @RequiresApi(api = Build.VERSION_CODES.N)
    public static void getBitmapFormView(View view, Activity activity, Callback callback) {
        Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), Bitmap.Config.ARGB_8888);

        int[] locations = new int[2];
        view.getLocationInWindow(locations);
        Rect rect = new Rect(locations[0], locations[1], locations[0] + view.getWidth(), locations[1] + view.getHeight());

        PixelCopy.request(activity.getWindow(), rect, bitmap, copyResult -> {
            if (copyResult == PixelCopy.SUCCESS) {
                callback.onResult(bitmap);
            }
        }, new Handler(Looper.getMainLooper()));
    }

感谢大家的支持，如有错误请指正，如需转载请标明原文出处！

原文地址：https://blog.csdn.net/szhupeng