How to create Bitmap form inflating FrameLayout (.. or other layout)

I got into a bit of trouble when I tried to create a dynamic layout and generate a Bitmap without displaying it on the screen, so I'll leave this as a note.

    fun createLayoutBitmap() {
        val frameLayout = createMeasuredFrameLayout()
        val bitmap = createBitmap(frameLayout)
        // save bitmap or set Views ...
    }

    fun createMeasuredFrameLayout(): FrameLayout {
        // inflate or new your layout
        return FrameLayout(context).apply {
            setBackgroundColor(Color.YELLOW)
            val tv = TextView(context).apply {
                text = "test"
            }
            // apply pixel size to TextView
            addView(tv, Rect(0, 0, 100, 200).toLayoutParams())
            // important: you need call measure() after build layout. do not add after measure(). my mistaken  point.
            measure(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        }
    }

    fun createBitmap(view: View): Bitmap {
        // apply drawing bitmap size in pixel.
        val rect = Rect(0, 0, 500, 500)
        return Bitmap.createBitmap(rect.width(), rect.height(), Bitmap.Config.ARGB_8888).also {
            view.layout(rect.left, rect.top, rect.width(), rect.height())
            view.draw(Canvas(it))
        }
    }
    // rect is intuitive.
    fun Rect.toLayoutParams(): ViewGroup.LayoutParams {
        return FrameLayout.LayoutParams(width(), height()).apply {
            leftMargin = left
            topMargin = top
        }
    }

this is a very easy sample code.