Android：在导航抽屉中的文本旁边添加图标

Question

I already created an activity which displays navigation drawer and i want to add an icon beside the textview. But when I run, the icon still doesn't show up.I'll post my codes and please help me for the mistakes. Thanks in advance.

STRINGS

<string-array name="nav_drawer_labels">
    <item>@string/nav_item_doctor</item>
    <item>@string/nav_item_hospital</item>
    <item>@string/nav_item_pharmacy</item>
    <item>@string/nav_item_clinic</item>
</string-array>

<string name="title_pharmacy">Pharmacy</string>
<string name="title_hospital">Hospital</string>
<string name="title_doctor">Doctor</string>
<string name ="title_clinic">Specialty Clinic</string>

<array name="nav_drawer_icons">
    <item>@drawable/ic_doctor</item>
    <item>@drawable/ic_hospital</item>
    <item>@drawable/ic_pharmacy</item>
    <item>@drawable/ic_clinic</item>
</array>

MAIN ACTIVITY

public class MainActivity extends AppCompatActivity implements FragmentDrawer.FragmentDrawerListener {

private static String TAG = MainActivity.class.getSimpleName();

private Toolbar mToolbar;
private FragmentDrawer drawerFragment;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mToolbar = (Toolbar) findViewById(R.id.toolbar);

    setSupportActionBar(mToolbar);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    drawerFragment = (FragmentDrawer)
            getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);
    drawerFragment.setUp(R.id.fragment_navigation_drawer, (DrawerLayout) findViewById(R.id.drawer_layout), mToolbar);
    drawerFragment.setDrawerListener(this);

    // display the first navigation drawer view on app launch
    displayView(0);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onDrawerItemSelected(View view, int position) {
    displayView(position);
}

private void displayView(int position) {
    Fragment fragment = null;
    String title = getString(R.string.app_name);
    switch (position) {
        case 0:
            fragment = new FragmentDoctor();
            title = getString(R.string.title_doctor);
            break;
        case 1:
            fragment = new FragmentHospital();
            title = getString(R.string.title_hospital);
            break;
        case 2:
            fragment = new FragmentPharmacy();
            title = getString(R.string.title_pharmacy);
            break;
        default:
            break;
    }

    if (fragment != null) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.replace(R.id.container_body, fragment);
        fragmentTransaction.commit();

        // set the toolbar title
        getSupportActionBar().setTitle(title);
    }
}

NAVIGATION DRAWER ADAPTER

public class NavigationDrawerAdapter extends RecyclerView.Adapter<NavigationDrawerAdapter.MyViewHolder> {
List<NavDrawerItem> data = Collections.emptyList();
private LayoutInflater inflater;
private Context context;

public NavigationDrawerAdapter(Context context, List<NavDrawerItem> data) {
    this.context = context;
    inflater = LayoutInflater.from(context);
    this.data = data;
}

public void delete(int position) {
    data.remove(position);
    notifyItemRemoved(position);
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.nav_drawer_row, parent, false);
    MyViewHolder holder = new MyViewHolder(view);
    return holder;
}

@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
    NavDrawerItem current = data.get(position);
    holder.title.setText(current.getTitle());
    holder.icon.setImageResource(current.getIcon());
}

@Override
public int getItemCount() {
    return data.size();
}

class MyViewHolder extends RecyclerView.ViewHolder {
    TextView title;
    ImageView icon;

    public MyViewHolder(View itemView) {
        super(itemView);
        title = (TextView) itemView.findViewById(R.id.title);
        icon = (ImageView) itemView.findViewById(R.id.imageView);
    }
}

NAVDRAWERITEM

public class NavDrawerItem {
private String title;
private int icon;


public NavDrawerItem() {

}

public NavDrawerItem( String title, int icon) {
    this.title = title;
    this.icon = icon;
}
public String getTitle() {
    return title;
}

public void setTitle(String title) {
    this.title = title;
}

public int getIcon(){return  icon;}

public void setIcon(int icon){
    this.icon = icon;
}

Answer 1

On your MainActivity declare:

getSupportActionBar().setDisplayShowHomeEnabled(true);

along with:

getSupportActionBar().setIcon(R.drawable.ic_launcher);

Answer 2

In the code that you have posted, at no time do you actually load an icon resource. Also, you have created arrays in your resources that you never load. Were you planning to use them to create NavDrawerItem objects using them?