【背景】
之前用ADT去调试某个android的app时，出现问题：
无法调试了。
console中log是：
[2013-11-26 15:58:49 - xxxxxx] Android Launch! [2013-11-26 15:58:49 - xxxxxx] adb is running normally. [2013-11-26 15:58:49 - xxxxxx] Performing com.yyy.xxxxxx.activities.MainActivity activity launch [2013-11-26 15:58:49 - xxxxxx] Refreshing resource folders. [2013-11-26 15:58:49 - xxxxxx] Starting incremental Pre Compiler: Checking resource changes. [2013-11-26 15:58:49 - xxxxxx] Nothing to pre compile! [2013-11-26 15:58:49 - xxxxxx] Starting incremental Package build: Checking resource changes. [2013-11-26 15:58:49 - xxxxxx] Skipping over Post Compiler. [2013-11-26 15:58:49 - OpenFile] Refreshing resource folders. [2013-11-26 15:58:49 - USBDemoTest] Refreshing resource folders. [2013-11-26 15:58:49 - USBDemoTest] Starting incremental Pre Compiler: Checking resource changes. [2013-11-26 15:58:49 - USBDemoTest] Nothing to pre compile! [2013-11-26 15:58:49 - UsbSerialExamples] Refreshing resource folders. [2013-11-26 15:58:49 - UsbSerialExamples] Starting incremental Pre Compiler: Checking resource changes. [2013-11-26 15:58:49 - UsbSerialExamples] Nothing to pre compile! [2013-11-26 15:59:05 - xxxxxx] Uploading xxxxxx.apk onto device 'c080846d3761911' [2013-11-26 15:59:05 - xxxxxx] Installing xxxxxx.apk... [2013-11-26 15:59:08 - xxxxxx] Re-installation failed due to different application signatures. [2013-11-26 15:59:08 - xxxxxx] You must perform a full uninstall of the application. WARNING: This will remove the application data! [2013-11-26 15:59:08 - xxxxxx] Please execute 'adb uninstall com.yyy.xxxxxx' in a shell. [2013-11-26 15:59:08 - xxxxxx] Launch canceled!
如图：
对应的原因是：
之前android的pad上面的此app是之前的某个版本，和当前新编译的版本不匹配。
所以需要去：
到android的pad中卸载此app
然后重新调试，就可以了：
[2013-11-26 16:01:44 - xxxxxx] Android Launch!
[2013-11-26 16:01:44 - xxxxxx] adb is running normally.
[2013-11-26 16:01:44 - xxxxxx] Performing com.yyy.xxxxxx.activities.MainActivity activity launch
[2013-11-26 16:01:47 - xxxxxx] Uploading xxxxxx.apk onto device 'c080846d3761911'
[2013-11-26 16:01:47 - xxxxxx] Installing xxxxxx.apk...
[2013-11-26 16:01:55 - xxxxxx] Success!
[2013-11-26 16:01:55 - xxxxxx] Starting activity com.yyy.xxxxxx.activities.MainActivity on device c080846d3761911
[2013-11-26 16:01:56 - xxxxxx] ActivityManager: Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.yyy.xxxxxx/.activities.MainActivity }
[2013-11-26 16:01:56 - xxxxxx] Attempting to connect debugger to 'com.yyy.xxxxxx' on port 8600如图：
所以：
如果以后遇到类似的，无法调试，看看是不是由于signature不匹配，如果是，则卸载旧的，重新调试（会自动安装新的），就可以正常调试了。