How to add a SearchWidget to the ActionBar?

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.

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>

This is the method where the Exception is thrown:

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 );
}

Complete stack trace:

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)

回答1:

use this way as in link

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;
    }

回答2:

Since this question is looked up quite often and I stumbled across the very same problem again and again here is a little follow up that keeps track of all necessary steps to create a SearchWidget.

There is one tricky part about the SearchWidget though: If you use hardcoded Strings in the searchable.xml instead of resources the app will crash with a confusing error message. This took me way too many hours of my life...

1. Create an Activity to handle the search results

   public class Search extends Activity {}
   

2. Add a file "searchable.xml" to your res/xml directory (use resources for hint & label!)

   <searchable xmlns:android="http://schemas.android.com/apk/res/android"
       android:hint="@string/search_hint"
       android:includeInGlobalSearch="false"
       android:label="@string/search_label"
       android:searchSettingsDescription="@string/search_global_description" />
   

3. Create the proper menu item "main.xml" in you res/menu directory

   <?xml version="1.0" encoding="utf-8"?>
   <menu xmlns:android="http://schemas.android.com/apk/res/android" >
   
       <item
          android:id="@+id/options_menu_main_search"
          android:actionViewClass="android.widget.SearchView"
          android:icon="@drawable/icon_magnifier"
          android:showAsAction="always"
          android:title="Search"/>
   
   </menu>
   

4. Update your Manifest.xml: Add the search activity and specify which activities may receive search intents. Adding <meta-data android:name="android.app.default_searchable" android:value=".app.Search" /> to an activity node makes it searchable. Adding it to the application node makes all activities searchable.

   <?xml version="1.0" encoding="utf-8"?>
   <manifest xmlns:android="http://schemas.android.com/apk/res/android">
       <application>
           <meta-data
               android:name="android.app.default_searchable"
               android:value=".app.Search" />
   
           <activity android:name=".activities.Search" >
               <intent-filter>
               <action android:name="android.intent.action.SEARCH" />
           </intent-filter>
   
           <meta-data
               android:name="android.app.searchable"
               android:resource="@xml/searchable" />
       </activity>
   </application>
   

5. Add the SearchManager to your ActionView in every activity that should provide the SearchWidget

   public class Activity extends android.app.Activity
   {
       @Override
       public boolean onCreateOptionsMenu( Menu menu )
       {
           getMenuInflater().inflate( R.menu.main, menu );
   
           // Add SearchWidget.
           SearchManager searchManager = (SearchManager) getSystemService( Context.SEARCH_SERVICE );
           SearchView searchView = (SearchView) menu.findItem( R.id.options_menu_main_search ).getActionView();
   
           searchView.setSearchableInfo( searchManager.getSearchableInfo( getComponentName() ) );
   
           return super.onCreateOptionsMenu( menu );
       }
   }
   

回答3:

If you are using targeting Android 2.x and using android.support.v7.widget.SearchView check that your menu.xml looks like this (note the yourapp namespace)

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:yourapp="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/search"
        android:title="@string/search"
        android:icon="@drawable/ic_search"
        yourapp:showAsAction="always"
        yourapp:actionViewClass="android.support.v7.widget.SearchView" />
</menu>

And in the Activity where you inflate the menu use:

android.support.v7.widget.SearchView searchView = (android.support.v7.widget.SearchView) 
MenuItemCompat.getActionView(menu.findItem(R.id.search));

回答4:

SearchView getActionView returning null

As in the link, open your menu xml file and change

android:actionViewClass="android.widget.SearchView"

into

app:actionViewClass="android.widget.SearchView" 

this worked for me

回答5:

I also got the same problem. In my case, change android:actionViewClass to app:actionViewClass solved the problem (with xmlns:app="http://schemas.android.com/apk/res-auto" in <menu> tag).

回答6:

This problem is triggered by a missing intent filter:

<intent-filter>
    <action android:name="android.intent.action.SEARCH" />
</intent-filter>

回答7:

First of all, create an XML file containing the SearchWidget to your layout folder

<?xml version="1.0" encoding="utf-8"?>
<SearchView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/edit_query"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:inputType="textFilter"
    >

</SearchView>

Then, in your activity, retrieve the action bar

android.support.v7.app.ActionBar actionBar = getSupportActionBar();

Then add a reference to your search view

 actionBar.setCustomView(R.layout.custom_action_bar);
    search = (EditText) actionBar.getCustomView().findViewById(
            R.id.edit_query);

Then, set the display option for the action bar

actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM | ActionBar.DISPLAY_HOME_AS_UP);

That's it.

Btw, you could also use my search widget which takes a list of strings as an array list and displays them, according to the query entered. Once the user selects a particular result, the selected result is returned which can retrieved on the onActivityResult of the parent activity.