问题
I was playing with the html5 geolocation api for a project I'm working on.
Latitude and longitude are reported correctly but altitude is always returned as 'null'.
Testing device is Nexus 4 and 5, has anybody else had similar problems with this api?
回答1:
Absolutely! it appears to be an issue that may be browser specific. Since I develop on both IPhones and Android I make sure to try my HTML5 apps on the default browsers (Safari and Android's webBrowser). My new IPhone 5S picks up the altitude just fine, but my Samsung Galaxy S4 continues to display "null". I built a native Android app version of my program to make sure it wasn't a device issue. It comes back with my altitude just fine. No answer, but still researching as altitude is important to us as well.
I also just verified using Chrome browser on same phone (S4); no altitude unless using my native app.
回答2:
The reason altitude is returned null is because, the device in question is **not** using GPS for location. Only when GPS is used, you'll get a value for altitude. If location provider is cell network, it won't be able to tell your altitude; that makes sense. Also, some OS might not report altitude accuracy, while reporting altitude.
来源：https://stackoverflow.com/questions/26264608/html5-geolocation-altitude