在nexus 7 4.3上，ecilpse下真机运行程序，在弹出的 android device chooser 窗口显示设备offline，
原因： 从4.2.2开始android有一个“安全的USB调试”功能。你
要明确授权给一台主机：
解决办法：需要更新adb. 我原先的 adb 版本 1.0.29. 升级为1.0.31后，运行adb devices后，在设备上弹出授权窗口，确认后，问题解决。
C:\Android\adt-bundle-windows-x86-20130729\adt-bundle-windows-x86-20130729\sdk\p
latform-tools>adb/?
Android Debug Bridge version 1.0.31
C:\Android\adt-bundle-windows-x86-20130729\adt-bundle-windows-x86-20130729\sdk\p
latform-tools>adb devices
adb server is out of date. killing...
* daemon started successfully *
List of devices attached
05f1a4e5 unauthorized
C:\Android\adt-bundle-windows-x86-20130729\adt-bundle-windows-x86-20130729\sdk\p
latform-tools>adb devices
List of devices attached
05f1a4e5 device
参考链接：http://grokbase.com/t/gg/android-developers/138kpghbw3/can-not-debug-galaxy-s4-mini
其它：
- Restart adb by issuing 'adb kill-server' followed by 'adb start-server' at a cmd prompt
- Disable and re-enable USB debugging on the phone
- Rebooting the phone if it still doesn't work.
99% of my issues have been resolved with these steps.