本文转载自:http://blog.csdn.net/morixinguan/article/details/56675914
frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java  +2519 \
 if (SystemProperties.getBoolean("ro.lockscreen.disable.default", false) == true) 
改为
 if (SystemProperties.getBoolean("ro.lockscreen.disable.default", true) == true) 
原文:http://www.cnblogs.com/zzb-Dream-90Time/p/7235087.html