Android Development: Post Screencap Image to Facebook wall

Android Development: Post Screencap Image to Facebook wall

i have been looking everywhere to find the correct way to post a image + text to facebook using android and facebook sdk. i can get this code to post just a message but when i try to post the screenshot i made it ends up with a null pointer exception. i have tried many different code snippets from other threads but none seem to work for me. the best i can do is this code which will post a message to my wall but not the photo. please tell me what im doing wrong here. much appreciated.
View content = findViewById(R.id.row1);
        Log.d("captureScreen", content.getId()+"");
        byte[] byteArray=null;
        Bitmap screenshot=null;
        try {
            if (content != null) {
                int width = content.getWidth();
                int height = content.getHeight();

                screenshot = Bitmap.createBitmap(width, height,
                        Bitmap.Config.RGB_565);
                content.draw(new Canvas(screenshot));
                Log.d("captureScreen", "success");
            }
        } catch (Exception e) {
            Log.d("captureScreen", "Failed");
        }

        try{


            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            screenshot.compress(Bitmap.CompressFormat.PNG, 100, stream);
            byteArray = stream.toByteArray();
            Log.d("byte array", "sucesss");
            } catch(Exception e){
                Log.d("byte array", "failed");
            }




        Request.Callback callback = new Request.Callback() {

            public void onCompleted(Response response) {


                JSONObject graphResponse = response.getGraphObject()
                .getInnerJSONObject();
                Log.d("onCompleted", "2 sucess");
                String postId = null;
                try {
                    postId = graphResponse.getString("id");
                    Log.d("onCompleted", "3 sucess");
                } catch (JSONException e) {
                    Log.d("json failed", "failed");
                    Log.i(TAG, "JSON error " + e.getMessage());
                }

                FacebookRequestError error = response.getError();
                if (error != null) {

                } else {

                    CreateDialog("your post was a sucess", "posted");
                }
            }

        };



      Bundle params = new Bundle();
      params.putString("message","tester");
    //params.putString("method", "photos.upload");
    //params.putByteArray("source", byteArray);
    // params.putString("caption", "test Caption");

        Request request = new Request(session, "me/photos", params,
                HttpMethod.POST, callback);

        RequestAsyncTask task = new RequestAsyncTask(request);
        task.execute();