我从开发者网站 http://developer.android.com/training/implementing-navigation/lateral.html下载了项目
it rais error in 2.2 device i had attchage v4jar file yet it throws error
08-27 05:20:35.352: E/AndroidRuntime(303): FATAL EXCEPTION: main
08-27 05:20:35.352: E/AndroidRuntime(303): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.android.effectivenavigation/com.example.android.effectivenavigation.MainActivity}: java.lang.ClassNotFoundException: com.example.android.effectivenavigation.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.example.android.effectivenavigation-1.apk]
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.os.Handler.dispatchMessage(Handler.java:99)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.os.Looper.loop(Looper.java:123)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread.main(ActivityThread.java:4627)
08-27 05:20:35.352: E/AndroidRuntime(303): at java.lang.reflect.Method.invokeNative(Native Method)
08-27 05:20:35.352: E/AndroidRuntime(303): at java.lang.reflect.Method.invoke(Method.java:521)
08-27 05:20:35.352: E/AndroidRuntime(303): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-27 05:20:35.352: E/AndroidRuntime(303): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-27 05:20:35.352: E/AndroidRuntime(303): at dalvik.system.NativeStart.main(Native Method)
08-27 05:20:35.352: E/AndroidRuntime(303): Caused by: java.lang.ClassNotFoundException: com.example.android.effectivenavigation.MainActivity in loader dalvik.system.PathClassLoader[/data/app/com.example.android.effectivenavigation-1.apk]
08-27 05:20:35.352: E/AndroidRuntime(303): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
08-27 05:20:35.352: E/AndroidRuntime(303): at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
08-27 05:20:35.352: E/AndroidRuntime(303): at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
08-27 05:20:35.352: E/AndroidRuntime(303): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)
08-27 05:20:35.352: E/AndroidRuntime(303): ... 11 more