android程序出现Unfortunately ...stopped 怎么进行调试啊，在网上也没有找到很合适的答案，这是一个程序出现的错误，求大神指点

[wx19940416]

04-13 05:55:47.857: E/AndroidRuntime(939): FATAL EXCEPTION: main
04-13 05:55:47.857: E/AndroidRuntime(939): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.textswitchertest/com.example.textswitchertest.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.textswitchertest.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.textswitchertest-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.textswitchertest-1, /system/lib]]
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.os.Handler.dispatchMessage(Handler.java:99)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.os.Looper.loop(Looper.java:137)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread.main(ActivityThread.java:5103)
04-13 05:55:47.857: E/AndroidRuntime(939): at java.lang.reflect.Method.invokeNative(Native Method)
04-13 05:55:47.857: E/AndroidRuntime(939): at java.lang.reflect.Method.invoke(Method.java:525)
04-13 05:55:47.857: E/AndroidRuntime(939): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
04-13 05:55:47.857: E/AndroidRuntime(939): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
04-13 05:55:47.857: E/AndroidRuntime(939): at dalvik.system.NativeStart.main(Native Method)
04-13 05:55:47.857: E/AndroidRuntime(939): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.textswitchertest.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.textswitchertest-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.textswitchertest-1, /system/lib]]
04-13 05:55:47.857: E/AndroidRuntime(939): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
04-13 05:55:47.857: E/AndroidRuntime(939): at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-13 05:55:47.857: E/AndroidRuntime(939): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
04-13 05:55:47.857: E/AndroidRuntime(939): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
04-13 05:55:47.857: E/AndroidRuntime(939): ... 11 more