boolean android.graphics.Bitmap.isRecycled() null object reference error

i had to Refactoring Androidx

actually, it's work before convert

first, Bitmap.createBitmap( .. ) in onDraw occured width, height > 0 error

so i had to fix code
if(mBitmap != null && !mBitmap.isRecycled()){
mBitmap.recycle();
...}

i can avoid this error but mPointerBitmap, mIconBitmap, mTitlesBitmap also occured same error

so i fixed it too

then new error come to me :(
boolean android.graphics.Bitmap.isRecycled() null object reference

mCanvas.drawBitmap(mPointerBitmap, 0.0F, 0.0F, mPointerPaint); << this code.

how can i fix it? plz help