iPad: Measure/detect covered area by a finger touch on screen (NOT only touch coordinates)

问题

I would like to get access to the area covered by a finger for each touch event on an IPad.

Every touch event will result in a coordinate pair X and Y independent of how big the finger and consequently the touch area is that triggered the event.

I was wondering if there is a way to get the area data which triggered the touch event e.g. size or coordinates NOT

Any help is much appreciated.

Thanks in advance for you answer or redirects,

Christian

回答1:

There is no public API for this. A private API exists in UITouch:

@property(assign, nonatomic, setter=_setPathMajorRadius:) CGFloat _pathMajorRadius;

but using this on AppStore will cause your app be rejected. See my answer in Is there any way at all that I can tell how hard the screen is being pressed for the usage of this property.

来源：https://stackoverflow.com/questions/3316358/ipad-measure-detect-covered-area-by-a-finger-touch-on-screen-not-only-touch-co