Bitmap from TextView (getDrawingCache) always null

Do this before getting drawing cache it will solve the problem

view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), 
            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight()); 

and then getDrawingCache() will return a bitmap and draw that bitmap on your canvas.

and if you are using bitmaps in your app prefer to clear them from memory by calling recycle() method on them so that bitmap get cleared from the memory for your safe side to avoid outOfMemoryException

Android has a maximum drawing cache size. If the drawing cache would be bigger than that, getDrawingCache() returns null. See the answer to this question.

You can find a workaround in the answer to this question.