今天拷贝一个开源项目到本项目中，出现：
threadid=1: thread exiting with uncaught exception (group=0x417cce00)问题，原因是Manfest.xml中activity的Theme与Appliacation的Theme冲突，将activity设置android:theme="@android:style/Theme.Holo.Light"问题得到解决。
出现这样的问题如：
1 W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41863e00) 2 E/AndroidRuntime: FATAL EXCEPTION: main 3 Process: com.xmfcdz.jingjia, PID: 21319 4 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.xmfcdz.jingjia/com.xmfcdz.jingjia.MarkActivity}: java.lang.NullPointerException 5 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2151) 6 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2279) 7 at android.app.ActivityThread.access$800(ActivityThread.java:142) 8 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1213) 9 at android.os.Handler.dispatchMessage(Handler.java:102)10 at android.os.Looper.loop(Looper.java:136)11 at android.app.ActivityThread.main(ActivityThread.java:5241)12 at java.lang.reflect.Method.invokeNative(Native Method)13 at java.lang.reflect.Method.invoke(Method.java:515)14 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:818)15 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634)16 at dalvik.system.NativeStart.main(Native Method)17 Caused by: java.lang.NullPointerException18 at com.xmfcdz.jingjia.MarkActivity. (MarkActivity.java:20)19 at java.lang.Class.newInstanceImpl(Native Method)20 at java.lang.Class.newInstance(Class.java:1208)21 at android.app.Instrumentation.newActivity(Instrumentation.java:1062)22 at com.qihoo360.mobilesafe.loader.c.newActivity(SourceFile:241)23 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2142)24 at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2279) 25 at android.app.ActivityThread.access$800(ActivityThread.java:142) 26 at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1213) 27 at android.os.Handler.dispatchMessage(Handler.java:102) 28 at android.os.Looper.loop(Looper.java:136) 29 at android.app.ActivityThread.main(ActivityThread.java:5241) 30 at java.lang.reflect.Method.invokeNative(Native Method) 31 at java.lang.reflect.Method.invoke(Method.java:515) 32 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:818) 33 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:634) 34 at dalvik.system.NativeStart.main(Native Method) 此类问题大多跟mainfest.xml文件配置问题有关，比如主题设置错误、未设置activity等。