java - 如何在 Android 中更改选定的选项卡标题 textSize

Question

我正在尝试找到一种方法来在选择时更改 Tab Title 的文本大小。到现在没有导出。希望有人能帮助我。

我的代码如下:

XML:

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

<android.support.design.widget.TabLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/tab_layout"
    app:tabSelectedTextColor="@android:color/holo_orange_dark"
    app:tabTextAppearance="@style/textAppearance">


</android.support.design.widget.TabLayout>


<android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/pager_view"/>

用于 tabTextAppearance 的样式:

<style name="textAppearance" parent="TextAppearance.Design.Tab">
    <item name="android:textSize">18sp</item>
    <item name="android:textStyle">bold</item>
</style>

我的适配器:

public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final Resources resources;
private static final int num = 3;

public ViewPagerAdapter(FragmentManager fm, Resources resources) {
    super(fm);
    this.resources = resources;
}

@Override
public Fragment getItem(int position) {
    Fragment fragment = null;

    switch (position) {
        case 0:
            fragment = new FragmentA();
            break;
        case 1:
            fragment = new FragmentB();
            break;
        case 2:
            fragment = new FragmentC();
            break;

    }

    return fragment;
}

@Override
public int getCount() {
    return num;
}

@Override
public CharSequence getPageTitle(int position) {
    String title = null;
    switch (position) {
        case 0:
            title = "A";
            break;
        case 1:
            title = "B";
            break;
        case 2:
            title = "C";
            break;
    }
    return title;
}
}

还有我的 Carousel Fragment 类:

 public class CarouselFragment extends Fragment {

    private TabLayout tabLayout;
    private ViewPager viewPager;
    private ViewPagerAdapter viewPagerAdapter;


    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.fragment_carousel, container, false);
        tabLayout = (TabLayout)root.findViewById(R.id.tab_layout);
        viewPager = (ViewPager)root.findViewById(R.id.pager_view);
        setHasOptionsMenu(true);
        return root;
    }

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


        viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager(), getResources());
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
            viewPager.setAdapter(viewPagerAdapter);
            tabLayout.setSelectedTabIndicatorColor(Color.RED);
            tabLayout.setupWithViewPager(viewPager);
        }else {
            viewPager.setAdapter(viewPagerAdapter);
            tabLayout.setupWithViewPager(viewPager);
        }

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
//here i should do something, but what???

            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
//here i should do something, but what???
            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
    }
}

非常感谢!

Answer 1

使用此代码

for (int i = 0; i < tabLayout.getTabCount(); i++) {

    TabLayout.Tab tab = tabLayout.getTabAt(i);
    if (tab != null) {

        TextView tabTextView = new TextView(this);
        tab.setCustomView(tabTextView);

        tabTextView.getLayoutParams().width = ViewGroup.LayoutParams.WRAP_CONTENT;
        tabTextView.getLayoutParams().height = ViewGroup.LayoutParams.WRAP_CONTENT;

        tabTextView.setText(tab.getText());

        if (i == 0) {
            tabTextView.setTextSize(16);
        }

    }

}
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        ViewGroup vg = (ViewGroup) tabLayout.getChildAt(0);
        ViewGroup vgTab = (ViewGroup) vg.getChildAt(tab.getPosition());
        int tabChildsCount = vgTab.getChildCount();
        for (int i = 0; i < tabChildsCount; i++) {
            View tabViewChild = vgTab.getChildAt(i);
            if (tabViewChild instanceof TextView) {
                ((TextView) tabViewChild).setTextSize(16);
            }
        }
    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {
        ViewGroup vg = (ViewGroup) tabLayout.getChildAt(0);
        ViewGroup vgTab = (ViewGroup) vg.getChildAt(tab.getPosition());
        int tabChildsCount = vgTab.getChildCount();
        for (int i = 0; i < tabChildsCount; i++) {
            View tabViewChild = vgTab.getChildAt(i);
            if (tabViewChild instanceof TextView) {
                ((TextView) tabViewChild).setTextSize(14);
            }
        }
    }
}