ios - What is the best practice for creating custom UIView's? -

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for creating custom views have 3 options.

  1. override

    func drawrect(_ rect: cgrect)

  2. add sub-layers view's layer.

  3. do both.

what best practice? why override drawrect if can draw in sub-layer (with easier api)?

thanks

rendering in drawrect means using cpu draw view using core graphics.

if can use composition of calayer sub-layers, better option heavy lifting done gpu.

on top of that, drawrect called on main thread, , if drawing code isn't fast app less responsive (of course can use background thread solve problem, still using cpu draw bitmap).


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