如何隐藏android应用程序的标题栏？

Question

有问题
我想从活动中隐藏标题栏（不编辑 xml），但总是出错

我尝试在几篇文章中使用建议：
Android title bar removal
How to hide app title in android
Make full screen activity

但这并没有使我达到预期的结果。我做错了什么？

IMG:http://i57.tinypic.com/wj6ud4.png

12-19 14:09:21.679      848-848/com.example.switchoff.test_app E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.switchoff.test_app/com.example.switchoff.test_app.MainActivity}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
            at android.app.ActivityThread.access$600(ActivityThread.java:130)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:137)
            at android.app.ActivityThread.main(ActivityThread.java:4745)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at android.support.v7.internal.app.WindowDecorActionBar.getDecorToolbar(WindowDecorActionBar.java:248)
            at android.support.v7.internal.app.WindowDecorActionBar.init(WindowDecorActionBar.java:201)
            at android.support.v7.internal.app.WindowDecorActionBar.<init>(WindowDecorActionBar.java:176)
            at android.support.v7.app.ActionBarActivityDelegateBase.createSupportActionBar(ActionBarActivityDelegateBase.java:156)
            at android.support.v7.app.ActionBarActivityDelegate.getSupportActionBar(ActionBarActivityDelegate.java:123)
            at android.support.v7.app.ActionBarActivityDelegateBase.onTitleChanged(ActionBarActivityDelegateBase.java:467)
            at android.support.v7.app.ActionBarActivity.onTitleChanged(ActionBarActivity.java:176)
            at android.app.Activity.onPostCreate(Activity.java:1000)
            at android.app.Instrumentation.callActivityOnPostCreate(Instrumentation.java:1142)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2042)
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
                at android.app.ActivityThread.access$600(ActivityThread.java:130)
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
                at android.os.Handler.dispatchMessage(Handler.java:99)
                at android.os.Looper.loop(Looper.java:137)
                at android.app.ActivityThread.main(ActivityThread.java:4745)
                at java.lang.reflect.Method.invokeNative(Native Method)
                at java.lang.reflect.Method.invoke(Method.java:511)
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
                at dalvik.system.NativeStart.main(Native Method)

Answer 1

在活动中使用this.requestWindowFeature(Window.FEATURE_NO_TITLE); 在setContentView(R.layout.yourlayout); 之前 或

 requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN); 

或对于ACTIONBAR 使用getActionBar().hide();

Answer 2

你不需要添加：

requestWindowFeature(Window.FEATURE_NO_TITLE);

我刚刚添加了：

  getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,                                
                                               WindowManager.LayoutParams.FLAG_FULLSCREEN);

然后在我的 style.xml 中，我有以下内容：

....
<style name="AppTheme" parent="android:Theme.Light">
    <!-- Customize your theme here. -->
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:screenOrientation">portrait</item>
    <item name="android:windowBackground">@drawable/logo</item>
</style>

这对我有用，希望这对你也有帮助......

Answer 3

你可以使用

getActionBar().hide();

或 getSupportActionBar().hide();

Answer 4

ActionBar actionBar = getActionBar();
actionBar.hide()