使用Fragments进行Android搜索

Question

有人知道一个教程或如何用s 实现标准Android搜索界面的例子Fragment吗？换句话说,是否可以SearchManager在片段中使用标准搜索？

Answer 1

总之,你不能.有几个原因导致Fragment无法在a中创建搜索界面.

1. 创建可搜索的界面时,您必须在Android清单中指定默认的"可搜索活动".我相信你知道,Fragment没有父母就不能存在Activity,因此,这种分离是不可能的.

2. 如果你已经想出了#1,我猜你问这个问题,希望有一些神奇的"黑客"可以完成工作.但是,文件说明,

   当用户在搜索对话框或窗口小部件中执行搜索时,系统会启动您的可搜索活动,并使用ACTION_SEARCH操作在Intent中提供搜索查询.您的可搜索活动从intent的QUERY extra中检索查询,然后搜索您的数据并显示结果.

   负责提供搜索结果的底层内部系统需要一个Activity而不是一个Fragment; 因此,实现完全独立于a的搜索界面是Activity不可能的,因为它需要更改底层系统本身.SearchableInfo如果你不相信我,请查看该课程的源代码:).

话虽如此,看起来似乎并不太难以实现类似于您所描述的内容.例如,您可以考虑实现您的可搜索活动,以便它接受android.intent.action.SEARCH意图并且(而不是立即在ListView例如中显示结果)将搜索查询传递给您的Fragments.例如,考虑以下可搜索的活动:

public class SearchableActivity extends Activity {

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

        if (Intent.ACTION_SEARCH.equals(getIntent().getAction())) {
          String query = intent.getStringExtra(SearchManager.QUERY);
          doMySearch(query);
        }
    }

    /**
     * Performs a search and passes the results to the container
     * Activity that holds your Fragments.
     */
    public void doMySearch(String query) {
        // TODO: implement this
    }
}

当发出搜索请求时,系统将启动您的可搜索活动,执行查询,并将结果传递给某个容器Activity(基于您的实现doMySearch).然后,容器Activity将这些结果传递给包含的可搜索的Fragment,其中将显示结果.实现需要比你可能希望的更多的工作,但我确信有一些方法可以使它更模块化,看起来这可能是你能做的最好的.

ps如果使用此方法,则可能必须特别注意向Backstack添加/删除哪些活动.有关如何执行此操作的更多信息,请参阅此文章.

pps您可能也完全忘记了标准搜索界面,只需Fragment在下面的Raghav帖子中描述的内部实现简单搜索.

Answer 2

以下是使用片段搜索内容的示例.希望它有所帮助,这就是你要找的东西:

public class LoaderCursor extends Activity {

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

        FragmentManager fm = getFragmentManager();

        // Create the list fragment and add it as our sole content.
        if (fm.findFragmentById(android.R.id.content) == null) {
            CursorLoaderListFragment list = new CursorLoaderListFragment();
            fm.beginTransaction().add(android.R.id.content, list).commit();
        }
    }

    public static class CursorLoaderListFragment extends ListFragment
            implements OnQueryTextListener, LoaderManager.LoaderCallbacks<Cursor> {

        // This is the Adapter being used to display the list's data.
        SimpleCursorAdapter mAdapter;

        // If non-null, this is the current filter the user has provided.
        String mCurFilter;

        @Override public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);

            // Give some text to display if there is no data.  In a real
            // application this would come from a resource.
            setEmptyText("No phone numbers");

            // We have a menu item to show in action bar.
            setHasOptionsMenu(true);

            // Create an empty adapter we will use to display the loaded data.
            mAdapter = new SimpleCursorAdapter(getActivity(),
                    android.R.layout.simple_list_item_2, null,
                    new String[] { Contacts.DISPLAY_NAME, Contacts.CONTACT_STATUS },
                    new int[] { android.R.id.text1, android.R.id.text2 }, 0);
            setListAdapter(mAdapter);

            // Start out with a progress indicator.
            setListShown(false);

            // Prepare the loader.  Either re-connect with an existing one,
            // or start a new one.
            getLoaderManager().initLoader(0, null, this);
        }

        @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
            // Place an action bar item for searching.
            MenuItem item = menu.add("Search");
            item.setIcon(android.R.drawable.ic_menu_search);
            item.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            SearchView sv = new SearchView(getActivity());
            sv.setOnQueryTextListener(this);
            item.setActionView(sv);
        }

        public boolean onQueryTextChange(String newText) {
            // Called when the action bar search text has changed.  Update
            // the search filter, and restart the loader to do a new query
            // with this filter.
            mCurFilter = !TextUtils.isEmpty(newText) ? newText : null;
            getLoaderManager().restartLoader(0, null, this);
            return true;
        }

        @Override public boolean onQueryTextSubmit(String query) {
            // Don't care about this.
            return true;
        }

        @Override public void onListItemClick(ListView l, View v, int position, long id) {
            // Insert desired behavior here.
            Log.i("FragmentComplexList", "Item clicked: " + id);
        }

        // These are the Contacts rows that we will retrieve.
        static final String[] CONTACTS_SUMMARY_PROJECTION = new String[] {
            Contacts._ID,
            Contacts.DISPLAY_NAME,
            Contacts.CONTACT_STATUS,
            Contacts.CONTACT_PRESENCE,
            Contacts.PHOTO_ID,
            Contacts.LOOKUP_KEY,
        };

        public Loader<Cursor> onCreateLoader(int id, Bundle args) {
            // This is called when a new Loader needs to be created.  This
            // sample only has one Loader, so we don't care about the ID.
            // First, pick the base URI to use depending on whether we are
            // currently filtering.
            Uri baseUri;
            if (mCurFilter != null) {
                baseUri = Uri.withAppendedPath(Contacts.CONTENT_FILTER_URI,
                        Uri.encode(mCurFilter));
            } else {
                baseUri = Contacts.CONTENT_URI;
            }

            // Now create and return a CursorLoader that will take care of
            // creating a Cursor for the data being displayed.
            String select = "((" + Contacts.DISPLAY_NAME + " NOTNULL) AND ("
                    + Contacts.HAS_PHONE_NUMBER + "=1) AND ("
                    + Contacts.DISPLAY_NAME + " != '' ))";
            return new CursorLoader(getActivity(), baseUri,
                    CONTACTS_SUMMARY_PROJECTION, select, null,
                    Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC");
        }

        public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
            // Swap the new cursor in.  (The framework will take care of closing the
            // old cursor once we return.)
            mAdapter.swapCursor(data);

            // The list should now be shown.
            if (isResumed()) {
                setListShown(true);
            } else {
                setListShownNoAnimation(true);
            }
        }

        public void onLoaderReset(Loader<Cursor> loader) {
            // This is called when the last Cursor provided to onLoadFinished()
            // above is about to be closed.  We need to make sure we are no
            // longer using it.
            mAdapter.swapCursor(null);
        }
    }
}

Answer 3

使用标准的ActionBar SearchView ActionView API可以在片段中进行搜索.这将使用AppCompat支持类v7返回到Android 2.1(API级别7).

在你的片段中:

@Override
public void onCreateOptionsMenu (Menu menu, MenuInflater inflater){
    inflater.inflate(R.menu.search, menu);
    MenuItem item = menu.findItem(R.id.action_search);
    SearchView sv = new SearchView(((YourActivity) getActivity()).getSupportActionBar().getThemedContext());
    MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW | MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
    MenuItemCompat.setActionView(item, sv);
    sv.setOnQueryTextListener(new OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            System.out.println("search query submit");
            return false;
        }

        @Override
        public boolean onQueryTextChange(String newText) {
            System.out.println("tap");
            return false;
        }
    });
}

在您的菜单XML中

<item
    android:id="@+id/action_search"
    android:icon="@drawable/ic_action_search"
    android:title="Search Waste Items"
    android:showAsAction="ifRoom|collapseActionView"
    nz.govt.app:actionViewClass="android.support.v7.widget.SearchView"
    nz.govt.app:showAsAction="ifRoom|collapseActionView" />

Answer 4

使用AppCompat支持类v7.只需从@Rookie解决方案中为@David的解决方案添加一些内容,以便以简单的方式使其正常工作,这里是我的片段代码:

MyFragment:

public class MyFragment extends Fragment implements SearchView.OnQueryTextListener {

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        // What i have added is this
        setHasOptionsMenu(true);
    }

    @Override
    public void onCreateOptionsMenu (Menu menu, MenuInflater inflater) {

        //inflater.inflate(R.menu.main, menu); // removed to not double the menu items
        MenuItem item = menu.findItem(R.id.action_search);
        SearchView sv = new SearchView(((MainActivity) getActivity()).getSupportActionBar().getThemedContext());
        MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW | MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
        MenuItemCompat.setActionView(item, sv);
        sv.setOnQueryTextListener(this);
        sv.setIconifiedByDefault(false);
        sv.setOnSearchClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Utils.LogDebug("Clicked: ");
            }
        });

        MenuItemCompat.setOnActionExpandListener(item, new MenuItemCompat.OnActionExpandListener() {
            @Override
            public boolean onMenuItemActionCollapse(MenuItem item) {
                // Do something when collapsed
                Utils.LogDebug("Closed: ");
                return true;  // Return true to collapse action view
            }

            @Override
            public boolean onMenuItemActionExpand(MenuItem item) {
                // Do something when expanded
                Utils.LogDebug("Openeed: ");
                return true;  // Return true to expand action view
            }
        });

        super.onCreateOptionsMenu(menu,inflater);
    }

    @Override
    public boolean onQueryTextSubmit(String query) {
        Utils.LogDebug("Submitted: "+query);
        return true;
    }

    @Override
    public boolean onQueryTextChange(String newText) {
        Utils.LogDebug("Changed: "+newText);
        return false;
    }
}

我添加了onActivityCreated,cuz没有调用setHasOptionsMenu(true);系统将不知道这个片段需要与菜单进行交互.

然后我删除了该行,inflater.inflate(R.menu.main, menu);因为它使菜单项加倍,因为Activity膨胀了一个菜单,然后Fragment膨胀了另一个菜单

感谢@David和@Rookie

Answer 5

与Fragments你合作时仍然需要使用一个Activity来控制和分配Fragments.这Activity可以像以前一样具有搜索功能.

我最近从基于"普通" Activity的应用程序切换到Fragment基于应用程序的应用程序,搜索功能对我来说也是如此.

你有没有尝试过它,但没有成功？如果是这样,请在您的问题中提供更多细节.

编辑:

如果你想要一个片段特定的搜索,让你所有的Fragments扩展一个接口MyFragment与一个startSearch方法,并让你Activity的startSearch方法调用当前片段的startSearch方法.

Answer 6

我想我已经实现了它:你实际上可以使用片段并在操作栏中添加搜索图标,以便在片段内进行搜索.诀窍是使用操作栏,操作视图,监听器,加载器和适配器.

虽然它完全绕过了android平台搜索机制(但它可以通过一些工作来完成,找到@Alex Lockwood描述的内容并将搜索传递给片段),但效果非常好.在活动的情况下,它不会对预期的意图作出反应,但它起作用:用户可以在片段内搜索.

这是代码:

SearchInFragmentActivity

package com.sof.test.searchfragment;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.view.View;

import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.ActionBar.Tab;
import com.actionbarsherlock.app.ActionBar.TabListener;
import com.actionbarsherlock.app.SherlockFragmentActivity;
import com.sof.test.searchfragment.SearchFragment;
import com.sof.test.R;


public class SearchInFragmentActivity extends SherlockFragmentActivity implements TabListener {

    private SearchFragment tab1 = new SearchFragment();
    private SearchFragment tab2 = new SearchFragment();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView( R.layout.search_in_fragments );

        getSupportActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
        createTab( R.string.tab1, R.drawable.ic_menu_search );
        createTab( R.string.tab2, R.drawable.ic_menu_search );
        getSupportActionBar().setSelectedNavigationItem( 0 );
        invalidateOptionsMenu();
    }

    private void createTab(int tabNameResId, int tabIconResId) {
        ActionBar.Tab tab = getSupportActionBar().newTab();
        tab.setText( tabNameResId );
        tab.setTabListener(this);
        getSupportActionBar().addTab(tab);
    }// met

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        if( ft == null ) {
            return;
        }//if
        View fragmentSlot = findViewById( R.id.fragment );
        Fragment newFragment = null;
        if( fragmentSlot != null ) {
            newFragment = (tab.getPosition() == 0) ? tab1 : tab2;
            ft.replace(R.id.fragment, newFragment );
            ft.setTransition( FragmentTransaction.TRANSIT_FRAGMENT_FADE);
        }//if
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }

}//class

片段类SearchFragment(我在上面的活动中使用了2个实例).

package com.sof.test.searchfragment;


import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
import android.support.v4.content.AsyncTaskLoader;
import android.support.v4.content.Loader;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.SearchView;
import android.widget.TextView;

import com.sof.test.R;
import com.actionbarsherlock.app.SherlockListFragment;
import com.actionbarsherlock.view.Menu;
import com.actionbarsherlock.view.MenuInflater;

public class SearchFragment extends SherlockListFragment {

    private StringLoader loader = null;
    private StringAdapter adapter = null;
    private List<String> listData = new ArrayList<String>();
    private String query;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = super.onCreateView(inflater, container, savedInstanceState);
        createListData();

        loader = new StringLoader( getActivity(), this );
        adapter = new StringAdapter(listData);
        setListAdapter(adapter);

        getLoaderManager().initLoader(0, null,  new LoaderCallBacks() );
        loader.forceLoad();
        setHasOptionsMenu( true );
        return view;
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater ) {
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate( R.menu.menu_search, menu);
        System.out.println( "inflating menu");

        final SearchView searchView = (SearchView) menu.findItem(R.id.menu_search).getActionView();
        final SearchView.OnQueryTextListener queryTextListener = new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextChange(String newText) {
                showFilteredItems( newText );
                return true;
            }

            @Override
            public boolean onQueryTextSubmit(String query) {
                return true;
            }
        };

        searchView.setOnQueryTextListener(queryTextListener);

        return;
    }//met

    private void showFilteredItems( String query ) {
        this.query = query;
        loader.onContentChanged();
    }

    private void createListData() {
        for( int i = 0; i < 100 ; i ++ ) {
          listData.add( "String "+ i ); 
        }
    }

    public List<String> getData() {
        List<String> listFilteredData = new ArrayList<String>();
        for( String string : listData ) {
            if( query == null || string.contains( query ) ) {
                listFilteredData.add( string );
            }
        }
        return listFilteredData;
    }//met

    private class LoaderCallBacks implements LoaderCallbacks< List<String>> {
        @Override
        public void onLoadFinished(Loader<List<String>> loader,
                List<String> listData) {
            adapter.setListData( listData );
        }// met

        @Override
        public void onLoaderReset(Loader<List<String>> listData) {
            adapter.setListData( new ArrayList<String>() );
        }// met

        @Override
        public Loader<List<String>> onCreateLoader(int arg0,
                Bundle arg1) {
            return loader;
        }// met
    }//class

    private class StringAdapter extends ArrayAdapter< String > {

        private List<String> listDataToDisplay = new ArrayList<String>();
        private LayoutInflater mInflater;

        public StringAdapter( List<String> listData ) {
            super( getActivity(), android.R.layout.simple_list_item_1, android.R.id.text1, listData );
            listDataToDisplay = listData;
            mInflater = (LayoutInflater)getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }//cons

        private void setListData( List<String> newListData ) {
            this.listDataToDisplay.clear();
            this.listDataToDisplay.addAll( newListData );
            notifyDataSetChanged();
        }//met

          /**
         * Populate new items in the list.
         */
        @Override public View getView(int position, View convertView, ViewGroup parent) {
            View view;

            if (convertView == null) {
                view = mInflater.inflate(android.R.layout.simple_list_item_1, parent, false);
            } else {
                view = convertView;
            }

            ((TextView)view.findViewById( android.R.id.text1)).setText( listDataToDisplay.get( position ) );

            return view;
        }
    }//inner class
}//class

class StringLoader extends AsyncTaskLoader<List<String>> {

    SearchFragment fragment = null;

    public StringLoader(Context context, SearchFragment fragment) {
        super(context);
        this.fragment = fragment;
    }// cons

    @Override
    public List<String> loadInBackground() {
        return fragment.getData();
    }// met
}// class

搜索片段res/menu/menu_search.xml菜单的xml文件:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:orientation="horizontal" >
    <FrameLayout
        android:id="@+id/fragment"
        android:layout_width="0px"
        android:layout_height="match_parent"
        android:layout_weight="1" />
</LinearLayout>

和xml布局文件res/layout/search_in_fragments.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:orientation="horizontal" >
    <FrameLayout
        android:id="@+id/fragment"
        android:layout_width="0px"
        android:layout_height="match_parent"
        android:layout_weight="1" />
</LinearLayout>

Answer 7

使用ActionBar和SearchView.您将能够处理搜索而无需任何与Activity的连接.只需设置一个OnQueryTextListenerSearchView即可.

MenuItem item = menu.add("Search");
SearchView sv = new SearchView(getActionBar().getThemedContext());
item.setActionView(sv);
item.setIcon(R.drawable.ic_search);
item.setShowAsAction(MenuItem.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW
        | MenuItem.SHOW_AS_ACTION_IF_ROOM);
sv.setOnQueryTextListener(new OnQueryTextListener() {
    @Override
    public boolean onQueryTextSubmit(String query) {
        //...
        return false;
    }
    @Override
    public boolean onQueryTextChange(String newText) {
        //...
        return false;
    }
});

有关自定义搜索的详细信息,请参阅此帖子.