求助吧里的大神，本人被一个问题困扰了半天。 求救啊T T

12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: FATAL EXCEPTION: main
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: Process: com.qqsystem.qq, PID: 3399
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.qqsystem.qq/com.qqsystem.qq.MainActivity}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.-wrap11(ActivityThread.java)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5417)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: Caused by: android.util.AndroidRuntimeException: requestFeature() must be called before adding content
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.android.internal.policy.PhoneWindow.requestFeature(PhoneWindow.java:317)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.Activity.requestWindowFeature(Activity.java:3650)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.qqsystem.qq.MainActivity.onCreate(MainActivity.java:13)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:6237)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.-wrap11(ActivityThread.java)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:102)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.os.Looper.loop(Looper.java:148)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5417)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at java.lang.reflect.Method.invoke(Native Method)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
12-17 06:30:22.460 3399-3399/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
写一个去掉标题栏一直报错 ,程序总是停止工作。 我的主函数顺序也没错啊。
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
}
}
求前辈指导。