一、简介
TabLayout提供了一个水平布局用于展示tabs，继承自HorizontalScrollView。一般与Viewpager结合使用实现页面和标签联动的效果，是时下APP中非常常用的一个控件
二、基本用法
1.添加design依赖
compile 'com.android.support:design:25.3.1'
2. xml引用
1. xml中添加tab
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab1"/>
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab2"/>
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab3"/>
<android.support.design.widget.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tab4"/>
</android.support.design.widget.TabLayout>
2. 代码中添加tab
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.design.widget.TabLayout>
// tablayout，Tab是TabLayout的内部类，且Tab的构造方法是包访问权限
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Tab1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab2"));
tabLayout.addTab(tabLayout.newTab().setText("Tab3"));
tabLayout.addTab(tabLayout.newTab().setText("Tab4"));
三、属性详解
<declare-styleable name="TabLayout">
<!--指示器颜色-->
<attr name="tabIndicatorColor" format="color"/>
<!--指示器高度-->
<attr name="tabIndicatorHeight" format="dimension"/>
<!--tabs距TabLayout开始位置的偏移量，但app:tabMode="scrollable"才生效-->
<attr name="tabContentStart" format="dimension"/>
<!--仅是Tab背景，设置TabLayout背景用android:background-->
<attr name="tabBackground" format="reference"/>
<!--默认fixed，所有Tab只能在屏幕内显示，超出会被挤压；scrollable,tab数量多会超出屏幕，可滑动-->
<attr name="tabMode">
<enum name="scrollable" value="0"/>
<enum name="fixed" value="1"/>
</attr>
<!--默认fill，tab填满TabLayout,但tabMode=“fixed”才生效；center，tabs位于TabLayout的中间-->
<attr name="tabGravity">
<enum name="fill" value="0"/>
<enum name="center" value="1"/>
</attr>
<!--Tab的最小宽度-->
<attr name="tabMinWidth" format="dimension"/>
<!--Tab的最大宽度-->
<attr name="tabMaxWidth" format="dimension"/>
<!--Tab文本设置样式-->
<attr name="tabTextAppearance" format="reference"/>
<!--Tab未选中字体颜色-->
<attr name="tabTextColor" format="color"/>
<!--Tab选中字体颜色-->
<attr name="tabSelectedTextColor" format="color"/>
<!--Tab内填充相关-->
<attr name="tabPaddingStart" format="dimension"/>
<attr name="tabPaddingTop" format="dimension"/>
<attr name="tabPaddingEnd" format="dimension"/>
<attr name="tabPaddingBottom" format="dimension"/>
<attr name="tabPadding" format="dimension"/>
</declare-styleable>
使用示例
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="@color/colorPrimaryDark"
app:tabIndicatorHeight="2dp"
app:tabContentStart="50dp"
app:tabBackground="@color/colorAccent"
app:tabMode="scrollable"
app:tabGravity="fill"
app:tabTextAppearance="@style/MyTabTextAppearance"
app:tabTextColor="@android:color/black"
app:tabSelectedTextColor="@android:color/white"/><style name="MyTabTextAppearance" parent="TextAppearance.Design.Tab">
<item name="textAllCaps">false</item>
<item name="android:textSize">18sp</item>
</style>
四、图文混排，Tab中添加图片
1. 通过SpannableString设置图片
@NonNull
private SpannableString setImageSpan(String string,int drawableId) {
SpannableString ss = new SpannableString(" "+string);
Drawable drawable = ContextCompat.getDrawable(this, drawableId);
drawable.setBounds(0,0,drawable.getIntrinsicWidth(),drawable.getIntrinsicHeight());
ImageSpan imageSpan = new ImageSpan(drawable);
ss.setSpan(imageSpan,0,1, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
return ss;
}
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText(setImageSpan("Tab1",R.drawable.ic_home)));
tabLayout.addTab(tabLayout.newTab().setText(setImageSpan("Tab2",R.drawable.ic_info)));
我们会发现个问题，通过ImageSpan设置的图片和文字没有对齐，先百度到一个可用方法解决：重写ImageSpan的draw()方法
package com.strivestay.tablayoutdemo;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.text.style.ImageSpan;
public class CenterImageSpan extends ImageSpan {
public CenterImageSpan(Drawable drawable) {
super(drawable);
}
public CenterImageSpan(Bitmap b) {
super(b);
}
@Override
public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom,
@NonNull Paint paint) {
Drawable b = getDrawable();
Paint.FontMetricsInt fm = paint.getFontMetricsInt();
int transY = (y + fm.descent + y + fm.ascent) / 2 - b.getBounds().bottom / 2;//计算y方向的位移
canvas.save();
canvas.translate(x, transY);//绘制图片位移一段距离
b.draw(canvas);
canvas.restore();
}
}
将上面的ImageSpan替换为现在的CenterImageSpan，即可实现图文混排时对齐
2. 通过Tab.setCustomView()设置图片
1. 自定义view布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:gravity="center">
<ImageView
android:id="@+id/iv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_home"/>
<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="2dp"
android:textSize="16sp"
android:text="首页"/>
</LinearLayout>
2. 代码设置
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setCustomView(setCustomView(R.drawable.ic_home,"首页")));
tabLayout.addTab(tabLayout.newTab().setCustomView(setCustomView(R.drawable.ic_info,"资讯")));
tabLayout.addTab(tabLayout.newTab().setCustomView(setCustomView(R.drawable.ic_live,"直播")));
tabLayout.addTab(tabLayout.newTab().setCustomView(setCustomView(R.drawable.ic_me,"我")));
private View setCustomView(int drawableId,String tabText) {
View view = View.inflate(this, R.layout.item_tab, null);
ImageView iv = (ImageView) view.findViewById(R.id.iv);
TextView tv = (TextView) view.findViewById(R.id.tv);
iv.setImageResource(drawableId);
tv.setText(tabText);
return view;
}
五、TabLayout与Viewpager联动
1. xml设置TabLayout和Viewpager
第一种：TabLayout放置在Viewpager的上方，放在AppbarLayout中会有阴影效果
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.strivestay.tablayoutdemo.MainActivity">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="@dimen/appbar_padding_top"
android:theme="@style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="@style/AppTheme.PopupOverlay">
</android.support.v7.widget.Toolbar>
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="@color/colorAccent"
app:tabIndicatorHeight="2dp"
app:tabBackground="@android:color/white"
app:tabTextAppearance="@style/MyTabTextAppearance"
app:tabTextColor="@android:color/black"
app:tabSelectedTextColor="@android:color/holo_blue_light">
</android.support.design.widget.TabLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="@dimen/fab_margin"
app:srcCompat="@android:drawable/ic_dialog_email"/>
</android.support.design.widget.CoordinatorLayout>
第二种：TabLayout直接放在Viewpager，无阴影
<android.support.v4.view.ViewPager
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<android.support.design.widget.TabLayout
android:id="@+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabIndicatorColor="@color/colorAccent"
app:tabIndicatorHeight="2dp"
app:tabBackground="@android:color/white"
app:tabTextAppearance="@style/MyTabTextAppearance"
app:tabTextColor="@android:color/black"
app:tabSelectedTextColor="@android:color/holo_blue_light">
</android.support.design.widget.TabLayout>
</android.support.v4.view.ViewPager>
2. 为Viewpager创建适配器
/**
* fragment
*/
public static class PlaceholderFragment extends Fragment {
private static final String ARG_SECTION = "section";
public PlaceholderFragment() {
}
public static PlaceholderFragment newInstance(String section) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putString(ARG_SECTION, section);
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getArguments().getString(ARG_SECTION));
return rootView;
}
}
/**
* pagerAdapter
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
String[] tabs = {"首页","资讯","直播","我"};
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
return PlaceholderFragment.newInstance(tabs[position]);
}
@Override
public int getCount() {
return tabs.length;
}
@Override
public CharSequence getPageTitle(int position) {
return tabs[position];
}
}
主要是重写getPageTitle()方法
3. 代码设置 TabLayout和Viewpager绑定
// tablayout
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
// vp
mViewPager = (ViewPager) findViewById(R.id.container);
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
mViewPager.setAdapter(mSectionsPagerAdapter);// 绑定，要在viewpager设置完数据后，调用此方法，否则不显示 tabs文本
tabLayout.setupWithViewPager(mViewPager);
调用setupWithViewPager()方法，则使用TabLayout.addtab()方法无效，TabLayout会清除之前添加的所有tabs，并将根据Viewpager的页数添加Tab，Tab标题为对应页通过getPageTitle()返回的文本
4. 图文混排
1. 同上，使用SpannableString
修改Adapter如下：
/**
* pagerAdapter
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
String[] tabs = {"首页","资讯","直播","我"};
int[] imgs = {R.drawable.ic_home,R.drawable.ic_info,R.drawable.ic_live,R.drawable.ic_me};
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
return PlaceholderFragment.newInstance(tabs[position]);
}
@Override
public int getCount() {
return tabs.length;
}
@Override
public CharSequence getPageTitle(int position) {
// return tabs[position];
return setImageSpan(tabs[position],imgs[position]);
}
}
setImageSpan()方法同上
2. 同上，使用Tab.setCustomView()
修改pagerAdapter如下：
/**
* pagerAdapter
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
String[] tabs = {"首页","资讯","直播","我"};
int[] imgs = {R.drawable.ic_home,R.drawable.ic_info,R.drawable.ic_live,R.drawable.ic_me};
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
return PlaceholderFragment.newInstance(tabs[position]);
}
@Override
public int getCount() {
return tabs.length;
}
@Override
public CharSequence getPageTitle(int position) {
// return tabs[position];
// return setImageSpan(tabs[position],imgs[position]);
return null;
}
/**
* 设置自定义view
* @param position
* @return
*/
public View setCustomView(int position) {
View view = View.inflate(getApplicationContext(), R.layout.item_tab, null);
ImageView iv = (ImageView) view.findViewById(R.id.iv);
TextView tv = (TextView) view.findViewById(R.id.tv);
iv.setImageResource(imgs[position]);
tv.setText(tabs[position]);
return view;
}
}
代码修改如下：
…………
// 绑定，要在viewpager设置完数据后，调用此方法，否则不显示 tabs文本
tabLayout.setupWithViewPager(mViewPager);
// 为绑定viewpager后的TabLayout的tabs设置自定义view
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
tabLayout.getTabAt(i).setCustomView(mSectionsPagerAdapter.setCustomView(i));
}
发现问题：我使用的仍然是上面的item_tab,但是只显示图片，不显示文字如下
翻了翻源码，也没发现有对Tab的标题有特别的设置；后来，就感觉是不是颜色问题，给item_tab中的textview加上属性android:textColor="@android:color/black",就显示出来了
六、FlycoTabLayout
这是一个不错的TabLayout开源项目，效果挺好，可以了解一下。
转载：https://blog.csdn.net/weixin_39251617/article/details/79032641
GitHub示例：ViewDemo/TabLayoutDemo