Android:以编程方式检测设备是否连接了硬件触摸屏

Question

我需要编写一个脚本来检测物理触摸屏是否在启动时连接到我的 Android 设备。我尝试通过 adb 列出文件夹 /dev/input 的内容，并获得以下输出:

root@q88:/dev/input # ls
event0
event1
event2
event3
event4
mice

如果我没记错的话，event0 标识了触摸屏，但无论是否连接触摸屏，它都是可见的。
有没有办法检测触摸屏是否连接到设备？

提前致谢。

Answer 1

您可以阅读 /proc/bus/input/devices 到 get details of your existing input devices .

根据您的硬件名称，您可以执行类似操作并检查是否有任何输出:

cat /proc/bus/input/devices | grep "Name=" | grep "Touch"

这是/proc/bus/input/devices的完整输出:

I: Bus=0011 Vendor=0002 Product=0008 Version=2222
N: Name="AlpsPS/2 ALPS DualPoint TouchPad"
P: Phys=isa0060/serio1/input0
S: Sysfs=/class/input/input2
H: Handlers=mouse1 event2 ts1
B: EV=f
B: KEY=420 0 70000 0 0 0 0 0 0 0 0
B: REL=3
B: ABS=1000003

[...] (blank line, next device)

The B in front stands for bitmap, N, P, S, U, H are simply first letter in corresponding name value and I is for ID. In ordered fashion:

• I → @id: id of the device (struct input_id)
  • Bus → id.bustype
  • Vendor → id.vendor
  • Product → id.product
  • Version → id.version
• N → name of the device
• P → physical path to the device in the system hierarchy
• S → sysfs path
• U → unique identification code for the device (if device has it)
• H → list of input handles associated with the device
• B → bitmaps
  • PROP → device properties and quirks
  • EV → types of events supported by the device
  • KEY → keys/buttons this device has
  • MSC → miscellaneous events supported by the device
  • LED → leds present on the device
  • REL → relative address
  • ABS → absolute address

要测试设备是否实际连接，您可以尝试模拟事件并查看是否出现错误:

input tap [x] [y]

Android comes with an input command-line tool that can simulate miscellaneous input events.

• input → The command line tool to send events
  • tap → the action
  • [x] → X coordinate on the screen
  • [y] → Y coordinate on the screen