KeyLayout文件是一个将Linux上报键值映射为android键值的映射文件
可以有多个KeyLayout文件,但是有如下优先级
/system/usr/keylayout/Vendor_XXXX_Product_XXXX_Version_XXXX.kl
/system/usr/keylayout/Vendor_XXXX_Product_XXXX.kl
/system/usr/keylayout/DEVICE_NAME.kl
/data/system/devices/keylayout/Vendor_XXXX_Product_XXXX_Version_XXXX.kl
/data/system/devices/keylayout/Vendor_XXXX_Product_XXXX.kl
/data/system/devices/keylayout/DEVICE_NAME.kl
/system/usr/keylayout/Generic.kl
/data/system/devices/keylayout/Generic.kl
例如KeyLayout文件中有如下内容
key 59 MENU
key 102 HOME
key 114 VOLUME_DOWN
key 115 VOLUME_UP
key 116 POWER
key 143 WAKEUP
key 158 BACK
key 212 CAMERA
key 217 SEARCH
第二列的数字是include/uapi/linux/input.h中定义的,kernel上报的键值就是这个
第三列表示linux上报后映射为android的键
获取vendor号和input name
cat /proc/bus/input/devices
getevent -p
在文件frameworks/native/include/input/InputEventLabels.h如下
DEFINE_KEYCODE(VOLUME_DOWN),
而真正的键值是定义在frameworks/native/include/android/keycodes.h中
AKEYCODE_VOLUME_DOWN = 25,