在Android Studio的默认导航抽屉中添加图标

Question

Hi i just generate a navigation drawer using the sample in android studio and in my navagation drawer fragment (where the listview is) i have this code :

    public class NavigationDrawerFragment extends Fragment {

    /**
     * Remember the position of the selected item.
     */
    private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";

    /**
     * Per the design guidelines, you should show the drawer on launch until the user manually
     * expands it. This shared preference tracks this.
     */
    private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";

    /**
     * A pointer to the current callbacks instance (the Activity).
     */
    private NavigationDrawerCallbacks mCallbacks;

    /**
     * Helper component that ties the action bar to the navigation drawer.
     */
    private ActionBarDrawerToggle mDrawerToggle;

    private DrawerLayout mDrawerLayout;
    private ListView mDrawerListView;
    private View mFragmentContainerView;

    private int mCurrentSelectedPosition = 0;
    private boolean mFromSavedInstanceState;
    private boolean mUserLearnedDrawer;

    public NavigationDrawerFragment() {
    }

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

        // Read in the flag indicating whether or not the user has demonstrated awareness of the
        // drawer. See PREF_USER_LEARNED_DRAWER for details.
        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
        mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);

        if (savedInstanceState != null) {
            mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
            mFromSavedInstanceState = true;
        }

        // Select either the default item (0) or the last selected item.
        selectItem(mCurrentSelectedPosition);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        // Indicate that this fragment would like to influence the set of actions in the action bar.
        setHasOptionsMenu(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        mDrawerListView = (ListView) inflater.inflate(
                R.layout.fragment_navigation_drawer, container, false);
        mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                selectItem(position);
            }
        });
        mDrawerListView.setAdapter(new ArrayAdapter<String>(
                getActionBar().getThemedContext(),
                android.R.layout.simple_list_item_activated_1,
                android.R.id.text1,
                new String[]{
                        getString(R.string.title_section1),
                        getString(R.string.title_section2),
                        getString(R.string.title_section3),
                        getString(R.string.title_section4),
                        getString(R.string.title_section5),
                        getString(R.string.title_section6),
                }));
        mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
        return mDrawerListView;
    }

    public boolean isDrawerOpen() {
        return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
    }

    /**
     * Users of this fragment must call this method to set up the navigation drawer interactions.
     *
     * @param fragmentId   The android:id of this fragment in its activity's layout.
     * @param drawerLayout The DrawerLayout containing this fragment's UI.
     */
    public void setUp(int fragmentId, DrawerLayout drawerLayout) {
        mFragmentContainerView = getActivity().findViewById(fragmentId);
        mDrawerLayout = drawerLayout;

        // set a custom shadow that overlays the main content when the drawer opens
        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
        // set up the drawer's list view with items and click listener

        ActionBar actionBar = getActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeButtonEnabled(true);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the navigation drawer and the action bar app icon.
        mDrawerToggle = new ActionBarDrawerToggle(
                getActivity(),                    /* host Activity */
                mDrawerLayout,                    /* DrawerLayout object */
                R.drawable.ic_drawer,             /* nav drawer image to replace 'Up' caret */
                R.string.navigation_drawer_open,  /* "open drawer" description for accessibility */
                R.string.navigation_drawer_close  /* "close drawer" description for accessibility */
        ) {
            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                if (!isAdded()) {
                    return;
                }

                getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
            }

            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                if (!isAdded()) {
                    return;
                }

                if (!mUserLearnedDrawer) {
                    // The user manually opened the drawer; store this flag to prevent auto-showing
                    // the navigation drawer automatically in the future.
                    mUserLearnedDrawer = true;
                    SharedPreferences sp = PreferenceManager
                            .getDefaultSharedPreferences(getActivity());
                    sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
                }

                getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
            }
        };

        // If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
        // per the navigation drawer design guidelines.
        if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
            mDrawerLayout.openDrawer(mFragmentContainerView);
        }

        // Defer code dependent on restoration of previous instance state.
        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mDrawerToggle.syncState();
            }
        });

        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    private void selectItem(int position) {
        mCurrentSelectedPosition = position;
        if (mDrawerListView != null) {
            mDrawerListView.setItemChecked(position, true);
        }
        if (mDrawerLayout != null) {
            mDrawerLayout.closeDrawer(mFragmentContainerView);
        }
        if (mCallbacks != null) {
            mCallbacks.onNavigationDrawerItemSelected(position);
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mCallbacks = (NavigationDrawerCallbacks) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mCallbacks = null;
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Forward the new configuration the drawer toggle component.
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // If the drawer is open, show the global app actions in the action bar. See also
        // showGlobalContextActionBar, which controls the top-left area of the action bar.
        if (mDrawerLayout != null && isDrawerOpen()) {
            inflater.inflate(R.menu.global, menu);
            showGlobalContextActionBar();
        }
        super.onCreateOptionsMenu(menu, inflater);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }

        if (item.getItemId() == R.id.action_example) {
            Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT).show();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * Per the navigation drawer design guidelines, updates the action bar to show the global app
     * 'context', rather than just what's in the current screen.
     */
    private void showGlobalContextActionBar() {
        ActionBar actionBar = getActionBar();
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setTitle(R.string.app_name);
    }

    private ActionBar getActionBar() {
        return ((ActionBarActivity) getActivity()).getSupportActionBar();
    }

    /**
     * Callbacks interface that all activities using this fragment must implement.
     */
    public static interface NavigationDrawerCallbacks {
        /**
         * Called when an item in the navigation drawer is selected.
         */
        void onNavigationDrawerItemSelected(int position);
    }
}

I want to add icon in front of each item of the list view but i dont know how to do this because i dont understand the whole code of the navigation drawer

Answer 1

创建一个自定义ArrayAdapter并在其中使用一个自定义布局，该布局具有ImageView和TextView

Answer 2

Try this

The xml file(call it whatever you want):

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Medium Text"
        android:id="@+id/textViewListItem"
        android:layout_marginTop="25dp"
        android:layout_marginLeft="10dp"
        android:layout_gravity="center_horizontal" />

    <ImageView
        android:layout_width="45dp"
        android:layout_height="45dp"
        android:layout_marginLeft="15dp"
        android:layout_marginTop="-40dp"
        android:id="@+id/imageView"
        android:src="@drawable/ic_launcher" />
</LinearLayout>

Create a class that will be your adapter , how your list wants to be(have an imageview, have 3 textviews, etc)

public class ListAdapter extends Activity {

    private int imageId;
    private String itemName;

    public ListaAdapter(int imageId, String itemName) {
        super();
        this.imageId = imageId;
        this.itemName = itemName;
    }

    public int getImageId() {
        return imageId;
    }

    public void setImageId(int imageId) {
        this.imageId = imageId;
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }
}

then in your activity that you would like the drawer to be implemented try

//instanciate components
private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mDrawerToggle;
private ListView mDrawerList;
private List<ListAdapter> drawerList = new ArrayList<ListAdapter>();

//in the onCreate method build 3 methods and organize your code

buildDrawer();
populateDrawerList();
buildListDrawer();

private void populateDrawerList() {
        drawerList.add(new ListaAdapter(R.drawable.icon_1, "String 1"));
        drawerList.add(new ListaAdapter(R.drawable.icon_2, "String 2"));
    }

    private void buildDrawer() {
        mDrawerLayout = (DrawerLayout)findViewById(R.id.your_drawer_layout);
        mDrawerToggle = new ActionBarDrawerToggle(YourActivity.this, mDrawerLayout, R.drawable.your_drawer_icon, "Open", "Closed"){
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                getActionBar().setTitle("Drawer Opened");
                invalidateOptionsMenu();
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                getActionBar().setTitle("Drawer Closed");
                invalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    private void buildListDrawer() {
        mDrawerList = (ListView)findViewById(R.id.listViewDrawer);
        ArrayAdapter<ListAdapter> adapter = new MyDrawerArrayAdapter();
        mDrawerList.setAdapter(adapter);
        mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(MyActivity.this, "You have chosen " + drawerList.get(position).getItemName(), Toast.LENGTH_SHORT).show();
            }
        });
    }

and then your modified Adapter that extends ArrayAdapter:

private class MyDrawerArrayAdapter extends ArrayAdapter<ListAdapter> {

        public MyDrawerArrayAdapter() {
            super(MyActivity.this, R.layout.drawer_list_item_layout, drawerList);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View drawerView = convertView;

            if(drawerView == null){
                drawerView = getLayoutInflater().inflate(R.layout.drawer_list_item_layout, parent, false);
            }

            ListAdapter currentPosition = drawerList.get(position);

            ImageView drawerImage = (ImageView)drawerView.findViewById(R.id.your_drawerImage);
            drawerImage.setImageResource(currentPosition.getImageId());

            TextView drawerText = (TextView)drawerView.findViewById(R.id.your_drawerText);
            drawerText.setText(currentPosition.getItemName());

            return drawerView;
        }
    }

Answer 3

Step 01 -
Have your res/drawable folder ready with appropriate icons.

Step 02 - In your values/string.xml add below

    <string-array name="mydrawerList">
      <item>item 1</item>
      <item>item 2</item>
      <item>item 3</item>
   </string-array>
   <array name="mydrawerList_icons">
      <item>@drawable/ic_for_item1</item>
      <item>@drawable/ic_for_item2</item>
      <item>@drawable/ic_for_item3</item>
   </array>

make sure you have icons in the "mydrawerList_icons" ordered as "mydrawerList" order.

Step 03 - in your NavigationDrawerFragment.java add below lines

private String[] listTitles;
private TypedArray listIcons;

in onCreate()

    listTitles = getResources().getStringArray(R.array.mydrawerList);
    listIcons = getResources().obtainTypedArray(R.array.mydrawerList_icons);

Step 04 - instead of this

            mDrawerListView.setAdapter(new ArrayAdapter<String>(
            getActionBar().getThemedContext(),
            android.R.layout.simple_list_item_activated_1,
            android.R.id.text1,
            new String[]{
                    getString(R.string.title_section1),
                    getString(R.string.title_section2),
                    getString(R.string.title_section3),
                    getString(R.string.title_section4),
                    getString(R.string.title_section5),
                    getString(R.string.title_section6),
            }));

type this

   mDrawerListView.setAdapter(new ArrayAdapter<String>(
            getActionBar().getThemedContext(),
            android.R.layout.simple_list_item_activated_1,
            android.R.id.text1,
            listTitles)
    {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View v = super.getView(position, convertView, parent);
            int resourceId = listIcons.getResourceId(position, 0);
            Drawable drawable = getResources().getDrawable(resourceId);
            ((TextView) v).setCompoundDrawablesWithIntrinsicBounds(drawable, null, null, null);
            return v;
        }
    });

Let me know the output.