我正在制作一个 Android 应用程序，当我构建并运行它时，应用程序停止并显示以下错误，我该怎么办？

Question

当我构建和运行我的代码时，我得到了 RunTimeExpection。这里是堆栈跟踪：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.besecure/com.example.besecure.MainActivity}: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2895)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1616)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:176)
    at android.app.ActivityThread.main(ActivityThread.java:6651)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)
Caused by: java.lang.IllegalStateException: This Activity already has an action bar supplied by the window decor. Do not request Window.FEATURE_SUPPORT_ACTION_BAR and set windowActionBar to false in your theme to use a Toolbar instead.
    at androidx.appcompat.app.AppCompatDelegateImpl.setSupportActionBar(AppCompatDelegateImpl.java:421)
    at androidx.appcompat.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:150)
    at com.example.besecure.MainActivity.onCreate(MainActivity.java:29)
    at android.app.Activity.performCreate(Activity.java:7088)
    at android.app.Activity.performCreate(Activity.java:7079)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
    ... 9 more

请帮帮我。谢谢

Answer 1

根据Nadir Belhaj的回答和MMG cmets，

在styles.xml试试这个代码：

<item name="windowActionBar">false</item> 
<item name="windowNoTitle">true</item>

Answer 2

您应该使用工具栏而不是操作栏。因此，在您的 styles.xml 中定义一个如下所示的主题并将其分配给清单中的应用程序或活动：

styles.xml：

<style name="AppTheme" parent="Theme.AppCompat.Light">
    <item name="windowActionBar">false</item>
</style>

或者：

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
</style>

清单：

<application
   ....
    android:icon="@drawable/xxx"
    android:theme="@style/AppTheme">
</application>

或

<activity android:name="xxx"  android:theme="@style/AppTheme"/>