在android studio中运行应用程序时出错

我是新的Android开发者，在我的设备上运行我的应用程序时，我面临以下错误。有人能帮我解决以下错误吗。谢谢你的帮助

E/AndroidRuntime: FATAL EXCEPTION: main
                                                                 Process: test1.uitflashlight, PID: 28312
                                                                 java.lang.RuntimeException: Unable to start activity ComponentInfo{test1.uitflashlight/test1.uitflashlight.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
                                                                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2345)
                                                                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2405)
                                                                     at android.app.ActivityThread.access$800(ActivityThread.java:149)
                                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1324)
                                                                     at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                     at android.os.Looper.loop(Looper.java:211)
                                                                     at android.app.ActivityThread.main(ActivityThread.java:5319)
                                                                     at java.lang.reflect.Method.invoke(Native Method)
                                                                     at java.lang.reflect.Method.invoke(Method.java:372)
                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1016)
                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811)
                                                                  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:359)
                                                                     at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:328)
                                                                     at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:289)
                                                                     at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
                                                                     at test1.uitflashlight.MainActivity.onCreate(MainActivity.java:23)
                                                                     at android.app.Activity.performCreate(Activity.java:5933)
                                                                     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
                                                                     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
                                                                     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2405) 
                                                                     at android.app.ActivityThread.access$800(ActivityThread.java:149) 
                                                                     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1324) 
                                                                     at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                     at android.os.Looper.loop(Looper.java:211) 
                                                                     at android.app.ActivityThread.main(ActivityThread.java:5319) 
                                                                     at java.lang.reflect.Method.invoke(Native Method) 
                                                                     at java.lang.reflect.Method.invoke(Method.java:372) 
                                                                     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1016) 
                                                                     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:811) 

---

错误显示在日志上 原因：java.lang.IllegalStateException:您需要在此活动中使用Theme.AppCompat主题（或子代）

活动必须使用App.Theme或其子体 在AndroidManifest.xml上

android:theme="@style/Theme"

---

由于Theme是从Theme.AppCompat扩展而来的，你能给我一些更多的信息吗？比如说，我的英语有点差