如何将 SearchWidget 添加到 ActionBar? [英] How to add a SearchWidget to the ActionBar?

问题描述

我正在尝试将 Search-ActionView 添加到我的应用程序中(如此处所述 http://developer.android.com/guide/topics/search/search-dialog.html#UsingSearchWidget).不幸的是，我不断收到 NullPointerException 异常，而且我很难检测到实际出了什么问题.

I'm trying to add a Search-ActionView to my application (as explained here http://developer.android.com/guide/topics/search/search-dialog.html#UsingSearchWidget). Unfortunately I keep getting a NullPointerException and I'm having a hard time detecting what's actually going wrong.

我创建了一个可搜索的配置和一个可搜索的活动，如 android 页面上所示.我的菜单 .xml 文件如下所示:

I created a searchable config and a searchable activity as shown on the android page. My menu .xml file looks like this:

<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    ...
    <item
        android:id="@+id/menu_item_search"
        android:actionViewClass="android.widget.SearchView"
        android:icon="@drawable/icon_search"
        android:showAsAction="always"
        android:title="@string/action_bar_button_search">
    </item>

</menu>

这是抛出异常的方法:

public boolean onCreateOptionsMenu( Menu menu )
{
    MenuInflater menuInflater = getMenuInflater();
    menuInflater.inflate( R.menu.action_bar, menu );

    SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
    SearchView searchView = (SearchView) menu.findItem(R.id.menu_item_search).getActionView();

    // NullPointerException thrown here; searchView is null.
    searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
    searchView.setIconifiedByDefault(false);

    return super.onCreateOptionsMenu( menu );
}

完整的堆栈跟踪:

FATAL EXCEPTION: main
java.lang.NullPointerException
at com.example.activities.Test.onCreateOptionsMenu(Test.java:41)
at android.app.Activity.onCreatePanelMenu(Activity.java:2444)
at com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:408)
at com.android.internal.policy.impl.PhoneWindow.invalidatePanelMenu(PhoneWindow.java:759)
at com.android.internal.policy.impl.PhoneWindow$1.run(PhoneWindow.java:2997)
at android.os.Handler.handleCallback(Handler.java:605)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4507)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
at dalvik.system.NativeStart.main(Native Method)

推荐答案

在 链接

public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.action_bar, menu);
        MenuItem searchItem = menu.findItem(R.id.menu_item_search);
        SearchView searchView = (SearchView) searchItem.getActionView();


        SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
        if(null!=searchManager ) {   
         searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        }
        searchView.setIconifiedByDefault(false);

        return true;
    }

这篇关于如何将 SearchWidget 添加到 ActionBar?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！