Question

我使用Android Studio中内置的Tabbed Activity创建了我的项目，我在不同的类中添加了3个标签及其各自的片段。

然后我尝试在每个标签上添加一个图标，但遇到了一些错误。

我的主要活动代码如下：

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代码，我试图在选项卡中添加一个Icon，如下所示：

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;
}
}

我使用Tab Host尝试获取Icon并在选项卡中显示它，但它不起作用。

有人可以一步一步地指导我如何实现这个目标吗？

请注意，我已经阅读了很多教程和示例，但是他们没有在选项卡中添加图标，在默认的选项卡式活动中，ActionBarActivity已扩展，ActionBar.TabListener在MainActivity中实现，片段是一个单独的类。

提前谢谢。

Answer 1

制作一个列表来保存图标，并将其设置如下：

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

向操作栏添加标签时，必须添加图标。

试试这个，

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

如何在Tabbed Activity Android的操作栏中为每个选项卡添加图标

2 个答案: