在 Android 中的 TabLayout 中将图标添加到选项卡

Question

我想在 Android 的 TabLayout 中向我的选项卡添加图标。我尝试了图标数组和 getTitle 方法。我没有得到任何图标。选项卡仅保留标题文本，根本不使用标题文本数组中的文本。这是我的代码：

import statements...

public class scatter extends FragmentActivity {
    some variable declarations...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scatter);
        sensorUID = getIntent().getStringExtra("sUID");
        tankname = getIntent().getStringExtra("tNAME");
        SCALE_C = (getIntent().getStringExtra("tSCALEC"));
        SCALE_M = (getIntent().getStringExtra("tSCALEM"));
        DPs = (getIntent().getStringExtra("tDP"));
        UNITs = (getIntent().getStringExtra("tUNIT"));
        numVar = Integer.parseInt(DPs);

       final ViewPager pager = (ViewPager) findViewById(R.id.viewPager);
        pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));

        TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
        tabLayout.addTab(tabLayout.newTab().setText("Graph"));
        tabLayout.addTab(tabLayout.newTab().setText("Values"));

        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
        pager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {

            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                pager.setCurrentItem(tab.getPosition());
            }

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

            }

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

            }
        });

    }



    private class MyPagerAdapter extends FragmentPagerAdapter {


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

        @Override
        public Fragment getItem(int pos) {
            Fragment fragment;
            Bundle args = new Bundle();
            args.putString("senID", sensorUID);
            args.putInt("numVar", numVar);

            switch (pos) {
                case 0:
                    fragment = FirstFragment.newInstance("FirstFragment, Instance 1");
                    break;
                case 1:
                    fragment = SecondFragment.newInstance("SecondFragment, Instance 1");
                    break;
                default:
                    fragment = FirstFragment.newInstance("FirstFragment, Instance 1");
                    break;
            }
            fragment.setArguments(args);
            return fragment;
        }


        @Override
        public int getCount() {
            return 2;
        }
    }
}

Answer 1

TabLayout.Tab 有一个 setIcon() 方法。

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
    tabLayout.addTab(tabLayout.newTab().setText("Graph").setIcon(R.drawable.ic_graph));
    tabLayout.addTab(tabLayout.newTab().setText("Values").setIcon(R.drawable.ic_values));

Answer 2

正如 active 所说，因为您可以为此使用自定义选项卡布局-

在 styles.xml 中定义自定义样式，然后将样式应用到您的 TabLayout：

<style name="MyCustomTabLayout" parent="Widget.Design.TabLayout">
<item name="tabIndicatorColor">#0000FF</item>
</style>

然后您可以为您的 TabLayout 覆盖此样式：

<android.support.design.widget.TabLayout
    android:id="@+id/tabs"
    style="@style/MyCustomTabLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
</android.support.design.widget.TabLayout>

可以为 TabLayout 配置其他几种样式：

<style name="MyCustomTabLayout" parent="Widget.Design.TabLayout">
<item name="tabMaxWidth">@dimen/tab_max_width</item>
<item name="tabIndicatorColor">?attr/colorAccent</item>
<item name="tabIndicatorHeight">2dp</item>
<item name="tabPaddingStart">12dp</item>
<item name="tabPaddingEnd">12dp</item>
<item name="tabBackground">?attr/selectableItemBackground</item>
<item name="tabTextAppearance">@style/MyCustomTabTextAppearance</item>
<item name="tabSelectedTextColor">?android:textColorPrimary</item>
</style>

<style name="MyCustomTabTextAppearance" parent="TextAppearance.Design.Tab">
<item name="android:textSize">14sp</item>
<item name="android:textColor">?android:textColorSecondary</item>
<item name="textAllCaps">true</item>
</style>

目前，TabLayout class 不提供允许在选项卡中使用图标的干净抽象模型。有许多已发布的解决方法，其中之一是 return 一个 SpannableString，它在 ImageSpan 中包含您的图标，来自您的

PagerAdapter's getPageTitle(position) method as shown in the code snippet below:

private int[] imageResId = {
    R.drawable.ic_one,
    R.drawable.ic_two,
    R.drawable.ic_three};
public CharSequence getPageTitle(int position) {     
Drawable image = ContextCompat.getDrawable(context, imageResId[position]);
 image.setBounds(0, 0, image.getIntrinsicWidth(),          

image.getIntrinsicHeight());
SpannableString sb = new SpannableString(" ");
ImageSpan imageSpan = new ImageSpan(image, ImageSpan.ALIGN_BOTTOM);
sb.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
return sb;}

默认情况下，TabLayout 创建的选项卡将 textAllCaps 属性设置为 true，这会阻止 ImageSpans 被渲染。您可以通过更改 tabTextAppearance 属性.

来覆盖此行为

<style name="MyCustomTabLayout" parent="Widget.Design.TabLayout">
  <item name="tabTextAppearance">@style/MyCustomTextAppearance</item>
</style>

<style name="MyCustomTextAppearance" parent="TextAppearance.Design.Tab">
  <item name="textAllCaps">false</item>
</style>

您可以添加图标和文字，如下所示- @覆盖 public CharSequence getPageTitle(int position) { // 根据项目位置生成标题可绘制图像 = context.getResources().getDrawable(imageResId[position]); image.setBounds(0, 0, image.getIntrinsicWidth(),

image.getIntrinsicHeight());
// Replace blank spaces with image icon
SpannableString sb = new SpannableString("   " + tabTitles[position]);
ImageSpan imageSpan = new ImageSpan(image, ImageSpan.ALIGN_BOTTOM);
sb.setSpan(imageSpan, 0, 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
return sb;
}

在 Android 中的 TabLayout 中将图标添加到选项卡

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