Efficient 2D drawing in Android

Question

I have searched for quite a few hours and have not been able to find a concise definite andswer to my question. I have an application where I need to draw a sports field (includ

Answer 1

You should definitely be caching any canvas drawing which will not change to a bitmap at initialization time and then draw that bitmap in onDraw(). That will help render times a lot. Something like:

Bitmap mField = null;

void init()
{
  mField = new Bitmap(...dimensions...);
  Canvas c = new Canvas(mField);
  c.drawRect(...);
  ...
}

void onDraw(Canvas c)
{
  c.drawBitmap(mField);
}