android 古怪问题解决集合

Unknown error: java.lang.NullPointerExceptionbox UnknownAndroid Packaging Problem

原因：Google官方给出了解决办法：
To fix this problem, simply delete the debug.keystore file. The default storage location for AVDs is in ~/.android/avd on OS X and Linux, in C:\Documents and Settings\\.android\ on Windows XP, and in C:\Users\\.android\ on Windows Vista.
The next time you build, the build tools will regenerate a new keystore and debug key
也就是删掉C:\Documents and Settings\Administrator\.android文件夹下的debug.keystore文件，然后重新build一下获取新的debug.keystore。这样新建项目时就正常了。

关于如何build 。
Eclipse能够自己build ，但是删除上面的.debug.keystore文件后，
需要强行build：
有两种实现：
1、Close Project  然后重新 Open Project
2、project  》 clean project

                                                                                                                                                                                      

 

Error generating final archive: Debug certificate expired on

删除C:\Documents and Settings\Administrator\.android\目录下的debug.keystore及ddms.cfg，