When the android program cannot run (stopped unexpectedly)

As a cainiao, I just learned Android for a few days and felt it was necessary to record my problems ......

Before writingProgramWhen,CodeIt was compiled on Eclipse, but it could not run on the virtual machine. It took a long time to find out that an activity was registered on androidmanifest. Therefore, the <activity Android: Name = ". menudemoactivity"
Android: Label = "@ string/app_name">
<Intent-filter>
<Action Android: Name = "android. Intent. Action. Main"/>
<Category Android: Name = "android. Intent. Category. launcher"/>
</Intent-filter>
</Activity>

in Android: Name = ". menudemoactivity", remove the code, compile the code, and add it to the original location. The program can run on the VM !! The reason is unknown. The privilege is recorded.