《Android第一行代码》2.4.3 Activitylifecylcetest代码运行时错误错误形式：点击按钮start dialog时程序停止运行
控制台输出：
08-30 20:44:57.532 1542-1542/com.example.sf.activitylifecycletest E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.sf.activitylifecycletest, PID: 1542 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sf.activitylifecycletest/com.example.sf.activitylifecycletest.DialogActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2368) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2420) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) at android.os.Handler.dispatchMessage(Handler.java:110) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:5324) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:829) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:645) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:356) at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:325) at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:286) at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139) at com.example.sf.activitylifecycletest.DialogActivity.onCreate(DialogActivity.java:11) at android.app.Activity.performCreate(Activity.java:5343) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2332) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2420) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342) at android.os.Handler.dispatchMessage(Handler.java:110) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:5324) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:829) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:645) at dalvik.system.NativeStart.main(Native Method)关键句：
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sf.activitylifecycletest/com.example.sf.activitylifecycletest.DialogActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.错误原因： 出现错误的原因是你试图加载的活动继承了ActionBarActivity或者AppCompatActivity类，而这两个类要求必须使用AppCompat主题 解决方法： 将继承的类由上述两个类改为Activity类即可，其它部分不用做更改。 更过信息可以参考： https://stackoverflow.com/questions/21814825
