android实现在照片上绘制涂鸦的方法

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>

  switch (model){
   case "MI 4LTE":
    scale = 1.1f;
    break;
   case "HUAWEI NXT-AL10":
    scale = 1.5f;
    break;
  }

 @Override
 public boolean onTouch(View view, MotionEvent motionEvent) {
  int action = motionEvent.getAction();
  switch (action) {
   case MotionEvent.ACTION_CANCEL:
    break;
   case MotionEvent.ACTION_DOWN:
    downX = motionEvent.getX() * scale;
    downY = motionEvent.getY() * scale;
    break;
   case MotionEvent.ACTION_UP:
    upX = motionEvent.getX() * scale;
    upY = motionEvent.getY() * scale;
    canvas.drawLine(downX, downY, upX, upY, paint);
    iv_drawpicture.invalidate();
    break;
   case MotionEvent.ACTION_MOVE:
    upX = motionEvent.getX() * scale;
    upY = motionEvent.getY() * scale;
    canvas.drawLine(downX, downY, upX, upY, paint);
    iv_drawpicture.invalidate();
    downX = upX;
    downY = upY;
    break;
   default:
    break;
  }
  return true;
 }

try {

  Uri imageUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, new ContentValues());
  OutputStream os = getContentResolver().openOutputStream(imageUri);

  //compress方法将图片转换成JPG或者PNG格式
  drawBitmap.compress(Bitmap.CompressFormat.JPEG, 90, os);
  Toast.makeText(this, "Saved：" + imageUri.toString(), Toast.LENGTH_LONG).show();
 } catch (FileNotFoundException e) {
  e.printStackTrace();
 }

 drawBitmap = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());
 canvas = createCanvas(drawBitmap);
 paint = createPaint();
 canvas.drawBitmap(bmp, 0, 0, paint);
 iv_drawpicture.setImageBitmap(drawBitmap);
 iv_drawpicture.setOnTouchListener(this);