iPhone front camera - tap to focus?

问题

I'm trying to figure out if tap-to-focus is possible via the front facing camera device. I've seen on the iPhone4 wikipedia that it supports focus, but not much more detail. When I call isFocusPointOfInterestSupported on the front facing camera it returns NO, so...I would assume that it isn't supported. However, the apple camera app seems to have some tap support on the front facing camera - is this focus or is it adjusting exposure at the tap point?

To what capacity is focus supported on the front facing camera?

Thanks in advance for any response.

回答1:

You can check on the Device Capture Settings of this page (documentation) that it doesn't support focus https://developer.apple.com/library/ios/#documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/04_MediaCapture.html#//apple_ref/doc/uid/TP40010188-CH5-SW2 and you can see it with your actual phone, even if you move it back and forth it wont change the focus unlike the back camera.

来源：https://stackoverflow.com/questions/9729898/iphone-front-camera-tap-to-focus