Make superlayer not visible

Question

I have added sublayers to my UIView's layer. However, the root layer(UIView's layer) is visible at background as white rectangle. How can I effeciently hide superlayer so there will be no resourses spent on compositing with sublayers?

Answer 1

Set the UIView's backgroundColor to [UIColor clearColor] and the opaque property to NO.

Answer 2

If you just want to hide the white rectangle, you can set the superlayer's opaque property to NO, its background color to a clear color (zero alpha), or you can set its frame to CGRectZero (if it's a UIView layer, that's not a good idea). However, note that there's always something behind your view, so making the background layer transparent/invisible doesn't exclude layer compositing. The only things that affect layer compositing speed are sublayer opaqueness and masks.

I would just set the UIView's background color to [UIColor clearColor] and its opaque property to false, and measure the effect in Instruments.