我做了一件显而易见的事——USB驱动程序是从最新的Android SDK安装的，USB调试在平板电脑中开启.
When the Nexus 7 is connected, the device shows up in the Windows Device Manager as "Android Phone" / "Android Composite ADB Device", with the properties showing driver version 6.0.0.0, so the correct driver is installed and working.
这也证明了该设备处于USB调试模式，因为如果不是这样，它会在Windows中的"便携设备"/"Nexus7"下显示.
问题是adb devices没有显示任何设备，而Eclipse也(毫不奇怪)没有提供Nexus 7作为硬件设备来运行应用程序.
我已重新启动两台设备，但均未生效.
我唯一能想到的调试是enable ADB_TRACE=all，但这并不能告诉我什么:
mkh@MULE ~/AppData/Local/Android/android-sdk/platform-tools
$ export ADB_TRACE=all
mkh@MULE ~/AppData/Local/Android/android-sdk/platform-tools
$ adb devices
system/core/adb/adb.c::main():Handling commandline()
system/core/adb/adb_client.c::adb_query():adb_query: host:devices
system/core/adb/adb_client.c::_adb_connect():_adb_connect: host:version
system/core/adb/sysdeps_win32.c::socket_loopback_client():socket_loopback_client: port 5037 type tcp => fd 100
system/core/adb/transport.c::writex():writex: fd=100 len=4: 30303063 000c
system/core/adb/transport.c::writex():writex: fd=100 len=12: 686f73743a76657273696f6e host:version
system/core/adb/transport.c::readx():readx: fd=100 wanted=4
system/core/adb/transport.c::readx():readx: fd=100 wanted=4 got=4
4f4b4159 OKAY
system/core/adb/adb_client.c::_adb_connect():_adb_connect: return fd 100
system/core/adb/adb_client.c::adb_connect():adb_connect: service host:devices
system/core/adb/transport.c::readx():readx: fd=100 wanted=4
system/core/adb/transport.c::readx():readx: fd=100 wanted=4 got=4
30303034 0004
system/core/adb/transport.c::readx():readx: fd=100 wanted=4
system/core/adb/transport.c::readx():readx: fd=100 wanted=4 got=4
30303164 001d
system/core/adb/sysdeps_win32.c::adb_close():adb_close: 100(lo-client:5037)
system/core/adb/adb_client.c::_adb_connect():_adb_connect: host:devices
system/core/adb/sysdeps_win32.c::socket_loopback_client():socket_loopback_client: port 5037 type tcp => fd 101
system/core/adb/transport.c::writex():writex: fd=101 len=4: 30303063 000c
system/core/adb/transport.c::writex():writex: fd=101 len=12: 686f73743a64657669636573 host:devices
system/core/adb/transport.c::readx():readx: fd=101 wanted=4
system/core/adb/transport.c::readx():readx: fd=101 wanted=4 got=4
4f4b4159 OKAY
system/core/adb/adb_client.c::_adb_connect():_adb_connect: return fd 101
system/core/adb/adb_client.c::adb_connect():adb_connect: return fd 101
system/core/adb/transport.c::readx():readx: fd=101 wanted=4
system/core/adb/transport.c::readx():readx: fd=101 wanted=4 got=4
30303030 0000
system/core/adb/transport.c::readx():readx: fd=101 wanted=0
system/core/adb/transport.c::readx():readx: fd=101 wanted=0 got=0
system/core/adb/sysdeps_win32.c::adb_close():adb_close: 101(lo-client:5037)
List of devices attached
***NOTHING SHOWN*****
我做错了什么？