Android rectf warning

I drew an ellipse on the canvas:

RectF f = new RectF(-r, -r, r, r);
canvas.drawOval(f , mPaint);  

Why do I see a warning on rectf?

resolvent:

This is what it says: executing a new rectf in OnDraw will create an object every time you draw anything. This may be many objects. Just use one rectf:

RectF mRect = new RectF();

protected void onDraw(Canvas canvas) {
    mRect.set(-r, -r, r, r);
    canvas.drawOval(mRect, mPaint);
}

It should be clear that your original code is logically correct. This is only a performance improvement (although very important)