问题
It seems like it would be super useful if an app existed for iPhone/Android that emulated a Bluetooth keyboard or mouse. e.g., you turn on the app, and suddenly you can type on your iPhone keyboard and your PC/PS3/etc. pairs with it as if it were a Bluetooth keyboard and receives the typed letters.
This idea seems so intuitive to me that I am thinking the only reason it doesn't exist is that it is not possible, but I don't understand why it wouldn't be possible.
Is there a limitation of Bluetooth which prevents a device from emulating a different type of device? Or, perhaps, a limitation in the APIs exposed by iOS or Android which would inhibit this?
EDIT: it looks like the iPhone Bluetooth APIs are fairly limited as you can only communicate with Apple-licensed accessories: Is it possible to develop an iOS app with bluetooth capabilities? This would presumably rule out anything along the lines of emulation of another type of device. The question is still open for Android though.
回答1:
I'm surprised nobody has answered pointing out BlueputDroid as an Android solution for that. At the link you can find further information about device compatibilities.
I know this thread is rather old but I think it's worth to let it documented so others would end up here as me and will find an answer, at least for the Android half of the question.
EDIT: if you have problems to get your device connected to your ps3 like I did, try this out: http://forum.xda-developers.com/showthread.php?p=19881739#post19881739
回答2:
The public iOS APIs do not currently appear to expose any functionality that would allow an app to make the iOS device to appear as a generic keyboard HID on Bluetooth.
However, iOS apps (iOS 4.2 and later?) can use external Bluetooth keyboards for input.
回答3:
This is possible on Blackberry 10 devices. Use the app called: bluetooth keyboard-mouse. I have been looking but I don't think Android or IOS have capability to appear as a bluetooth hid device
来源：https://stackoverflow.com/questions/8483246/can-a-phone-pretend-to-be-a-bluetooth-keyboard