Android 从URL向图像添加水印并共享

在共享之前，我想从我的绘图设备中添加一个水印图像（我的徽标），以便共享的图像具有半透明水印

到目前为止，我只能使用以下代码共享URL中的图像：

    public void shareItem(String url) {
        Picasso.with(getApplicationContext()).load(url).into(new Target() {
            @Override
            public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {

                shareIntent = new Intent(android.content.Intent.ACTION_SEND);
                shareIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                shareIntent.putExtra(Intent.EXTRA_STREAM, getLocalBitmapUri(bitmap));
                shareIntent.setType("image/png");
                startActivity(Intent.createChooser(shareIntent, "Share with"));
            }

            @Override
            public void onBitmapFailed(Drawable errorDrawable) {
            }

            @Override
            public void onPrepareLoad(Drawable placeHolderDrawable) {
            }
        });
    }
  public Uri getLocalBitmapUri(Bitmap bmp) {
        Uri bmpUri = null;
        try {
            File file = new File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "share_image_" + System.currentTimeMillis() + ".png");
            FileOutputStream out = new FileOutputStream(file);
            bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
            out.close();
            bmpUri = Uri.fromFile(file);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return bmpUri;
    }  

---

您可以在我的代码中将您的uri用作源代码，并为输出文件（带水印）创建新的uri，以便通过intent共享

这是电话号码

 String address = Environment.getExternalStorageDirectory().getAbsolutePath();

            Bitmap source = BitmapFactory.decodeResource(getResources(), R.drawable.birds); // the original file is cuty.jpg i added in resources
            Bitmap dest = addWatermark(source);
            try {
                dest.compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(new File(address + "/output.jpg")));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }

这种方法将完成相当的工作

public  Bitmap addWatermark( Bitmap source) {
        int width, height;
        Canvas canvas;
        Paint paint;
        Bitmap bitmap, watermark;
        Matrix matrix;
        float scale;
        RectF rectF;
        width = source.getWidth();
        height = source.getHeight();

        // Create a new bitmap file and draw it on the canvas
        bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG | Paint.FILTER_BITMAP_FLAG);
        canvas = new Canvas(bitmap);
        canvas.drawBitmap(source, 0, 0, paint);


        // now ready your  watermark from the resources
        watermark = BitmapFactory.decodeResource(getResources(), R.drawable.apple);


        // scale / adjust height of your logo/watermark
        // i am scaling it down to 30%
        scale = (float) (((float) height * 0.30) / (float) watermark.getHeight());
        // now create the matrix
        matrix = new Matrix();
        matrix.postScale(scale, scale);
        // Determine the post-scaled size of the watermark
        rectF = new RectF(0, 0, watermark.getWidth(), watermark.getHeight());
        matrix.mapRect(rectF);

        // below method will decide the position of the logo on the image
        //for right bottom corner use below line

       // matrix.postTranslate(width - rectF.width(), height - rectF.height());

        // i am going to add it my logo at the top left corner
        matrix.postTranslate(15,15);


        // set alpha/opacity of paint which is going to draw watermark
        paint.setAlpha(60);
        // now draw the watermark on the canvas
        canvas.drawBitmap(watermark, matrix, paint);

        //cleaning up the memory
        watermark.recycle();

        // now return the watermarked image to the calling location
        return bitmap;
    }

下面是之前的示例图像

左上角应用60%alpha水印后的图像