Differentiate between finger touch and hand/palm rest

问题

Is there any technique to differentiate between finger touch and palm rest on surface while drawing on touch surface in iOS touch based os?

Edit : Added android tag as question is relevant for any touch based os.

Thanks

回答1:

I can't speak for Android systems, but on iOS I do not believe there is any definitive distinction as all touches, regardless of surface area' are resolved to individual points.

That said, there are ways you could determine whether a specific touch is a palm or finger. If you are making a hand-writing App for instance, if you ask the user whether they are left or right handed then you could ignore all touches to the right/left of the touch that would logically be the finger/stylus. Your method for eliminating the "palm touches" would be specific to the App you are writing.

Something else I have noticed (although I hasten to add this is not particularly reliable!) is that a palm touch will often result in many small touches around the palm area rather than a single touch due to the shape of the palm, small palm movement/rolling, etc. If you know you only ever need to receive and use one touch, this may be something you can manipulate.

In the end, any technique you use to differentiate a palm touch from a finger touch will probably be logical, rather than API/hardware-available. Again, this is iOS specific I am not at all familiar with Android's touch system.

来源：https://stackoverflow.com/questions/11792510/differentiate-between-finger-touch-and-hand-palm-rest