getActionBar返回null [英] getActionBar returns null

问题描述

调用 getActionBar 返回空。这已被经常报道，所以我做了一定要包括他人已经使用的解决方案：我的的minSdkVersion = 11 ，我有一个标题栏，和我打电话 getActionBar 在的setContentView 。另外，我的活动是不是一个子活动。

Calling getActionBar returns null. This has been frequently reported so I've made sure to include the solutions others have used: My minSdkVersion=11, I do have a titlebar, and I'm calling getActionBar after setContentView. Also, my activity is not a child activity.

setContentView(R.layout.main);

// experiment with the ActionBar 
ActionBar actionBar = getActionBar();
actionBar.hide();

设备是三星Galaxy Tab 10.1运行Android 3.2

Device is a Samsung Galaxy Tab 10.1 running Android 3.2

先谢谢您的任何意见或建议！

Thanks in advance for any ideas or suggestions!

推荐答案

看来你需要请求或者通过一个主题或通过以下code有一个动作条（！=标题栏）。

It seems you need to request having an Actionbar (!= titlebar) either via a Theme or via below code.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // The Action Bar is a window feature. The feature must be requested
    // before setting a content view. Normally this is set automatically
    // by your Activity's theme in your manifest. The provided system
    // theme Theme.WithActionBar enables this for you. Use it as you would
    // use Theme.NoTitleBar. You can add an Action Bar to your own themes
    // by adding the element <item name="android:windowActionBar">true</item>
    // to your style definition.
    getWindow().requestFeature(Window.FEATURE_ACTION_BAR);

    setContentView(R.layout.main);

    // experiment with the ActionBar 
    ActionBar actionBar = getActionBar();
    actionBar.hide();
}

$ C $从[<一个C href="http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/ActionBarMechanics.html">here]

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