如何在TabbedActivity Android中的操作栏中向每个选项卡添加图标

Question

I have created my project by using the built in Tabbed Activity in Android Studio, I have added 3 tabs and their respective Fragments in separate classes.

Then I tried to add an icon to each Tab, but faced some errors.

My MainActivity Code is the following:

package appetizers.com.myvault;

import java.util.Locale;

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentPagerAdapter;
import android.os.Bundle;
import android.support.v4.view.ViewPager;

public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {

/**
 * The {@link android.support.v4.view.PagerAdapter} that will provide
 * fragments for each of the sections. We use a
 * {@link FragmentPagerAdapter} derivative, which will keep every
 * loaded fragment in memory. If this becomes too memory intensive, it
 * may be best to switch to a
 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 */
SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;


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

    // Set up the action bar.
    final ActionBar actionBar = getSupportActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // code to hide the action bar
    getSupportActionBar().setDisplayShowHomeEnabled(false);
    getSupportActionBar().setDisplayShowTitleEnabled(false);



    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    // When swiping between different sections, select the corresponding
    // tab. We can also use ActionBar.Tab#select() to do this if we have
    // a reference to the Tab.
    mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar.setSelectedNavigationItem(position);
        }

        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            super.onPageScrolled(position, positionOffset, positionOffsetPixels);
        }

        @Override
        public void onPageScrollStateChanged(int state) {
            super.onPageScrollStateChanged(state);
        }
    });

    // For each of the sections in the app, add a tab to the action bar.
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        // Create a tab with text corresponding to the page title defined by
        // the adapter. Also specify this Activity object, which implements
        // the TabListener interface, as the callback (listener) for when
        // this tab is selected.
        actionBar.addTab(
                actionBar.newTab()
                        .setText(mSectionsPagerAdapter.getPageTitle(i))
                        .setTabListener(this));
    }
}


@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
    // When the given tab is selected, switch to the corresponding page in
    // the ViewPager.
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a PlaceholderFragment (defined as a static inner class below).
        switch (position) {
            case 0:
                return new FragmentPassword();
            case 1:
                return new FragmentPicture();
            case 2:
                return new FragmentSettings();

        }
        return null;
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
            case 0:
                return getString(R.string.title_section1).toUpperCase(l);
            case 1:
                return getString(R.string.title_section2).toUpperCase(l);
            case 2:
                return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}
}

My Fragment code, where I am trying to add an Icon to the tab is the following:

package appetizers.com.myvault;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TextView;


public class FragmentPassword extends Fragment {
/**
 * The fragment argument representing the section number for this
 * fragment.
 */
private static final String ARG_SECTION_NUMBER = "section_number";

/**
 * Returns a new instance of this fragment for the given section
 * number.
 */
public static FragmentPassword newInstance(int sectionNumber) {
    FragmentPassword fragment = new FragmentPassword();
    Bundle args = new Bundle();
    args.putInt(ARG_SECTION_NUMBER, sectionNumber);
    fragment.setArguments(args);
    return fragment;
}

public FragmentPassword() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_password, container, false);


    TabHost tabHost = (TabHost) getActivity().findViewById(android.R.id.tabhost);

    View passwordTab = tabHost.getTabWidget().getChildAt(0);
    ImageView tabTitleIcon = (ImageView) passwordTab.findViewById(android.R.id.icon);
    tabTitleIcon.setImageResource(R.drawable.ic_launcher);

    return rootView;
}
}

I used the Tab Host to try to get the Icon and display it in the tab, but it is not working.

Can someone guide me, step by step, on how to achieve this ?

Please note, that I have went through many tutorials and examples, but non of them were adding an icon to tabs, in a default Tabbed Activity, where the ActionBarActivity is extended and the ActionBar.TabListener is implemented, in the MainActivity, and the Fragment is in a seperate class.

Thank you in advance.

Answer 1

Make a list to hold icons, and set them following:

ArrayList<int> iconList = new ArrayList<>();
//then put your icons by `R.drawable.icon_name` ids to list

// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
    // Create a tab with text corresponding to the page title defined by
    // the adapter. Also specify this Activity object, which implements
    // the TabListener interface, as the callback (listener) for when
    // this tab is selected.
    actionBar.addTab(
            actionBar.newTab()
                    .setText(mSectionsPagerAdapter.getPageTitle(i))
                    .setTabListener(this))
                    .setIcon(iconList.get(i));
}

Answer 2

You have to add the icons when you adding tabs to the action bar.

Try this,

                actionBar.addTabactionBar.newTab()
                    .setText(mSectionsPagerAdapter.getPageTitle(i))
                    .setIcon(getResources().getDrawable(R.drawable.ic_launcher))  // use what icon you need
                    .setTabListener(this));