介绍

几行代码实现Android选项卡界面，支持标准底部Tab自定义视图选项卡，头部文字选项卡。

底部自定义视图选项卡

先来看看实现下图中的效果我们代码应该怎么写？

实现上图效果只需以下代码：

public class TestBottomTabActivity extends TabActivity {    @Override    protected List getTabViews() {        List tabviews = new ArrayList();        tabviews.add(new TabItemView(this,"1",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"2",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"3",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"4",R.color.colorPrimary,R.mipmap.ic_launcher,0));        return tabviews;    }    @Override    protected List getFragments() {        List fragments = new ArrayList();        fragments.add(BlankFragment.newInstance("1",null));        fragments.add(BlankFragment.newInstance("2",null));        fragments.add(BlankFragment.newInstance("3",null));        fragments.add(BlankFragment.newInstance("4",null));        return fragments;    }    @Override    protected List getTitles() {        return null;    }    @Override    protected TabType getTabType() {        return TabType.BottomCustomViewTab;    }}

头部文字选项卡

先来看看实现下图中的效果我们代码应该怎么写？

实现上图效果只需以下代码：

public class TestTopTabActivity extends TabActivity {    @Override    protected List getTabViews() {        return null;    }    @Override    protected List getFragments() {        List fragments = new ArrayList();        fragments.add(BlankFragment.newInstance("1",null));        fragments.add(BlankFragment.newInstance("2",null));        fragments.add(BlankFragment.newInstance("3",null));        fragments.add(BlankFragment.newInstance("4",null));        return fragments;    }    @Override    protected List getTitles() {        List list = new ArrayList();        list.add("待支付");        list.add("待发货");        list.add("待收货");        list.add("待评价");        return list;    }    @Override    protected TabType getTabType() {        return TabType.TopTitleTab;    }}

实现

准备知识

我们都知道在android.support.design.widget包中为我们提供了TabLayout用来进行水平方向的tab展示，不清楚的同学可以先百度了解一下，用法很简单，大致如下：

        viewPager = (ViewPager) findViewById(R.id.viewPager);        tabLayout = (TabLayout) findViewById(R.id.tabLayout);         //为viewPager设置一个FragmentPagerAdapter        pagerAdapter = new SimpleFragmentPagerAdapter(getSupportFragmentManager(), this);        viewPager.setAdapter(pagerAdapter);        //进行关联        tabLayout.setupWithViewPager(viewPager);        tabLayout.setTabMode(TabLayout.MODE_FIXED);

实现一个头部文字选项卡

为了能够快速实现一个头部文字选项卡，我们可以将一些不变的代码写在一个父类Activity，让后提供抽象方法来让子类去实现会变化的代码，由此如果我们实现一个头头部文字选项卡抽象类如下：

1、首先定义布局
activity_tab_top.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"              android:orientation="vertical"              android:layout_width="match_parent"              android:layout_height="match_parent">    <android.support.design.widget.TabLayout        android:id="@+id/tabLayout"        android:layout_width="match_parent"        android:layout_height="48dp">android.support.design.widget.TabLayout>    <View        android:layout_width="match_parent"        android:layout_height="1dp"        android:background="#d3d3d3"        android:orientation="vertical">    View>    <android.support.v4.view.ViewPager        android:id="@+id/viewPager"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1">android.support.v4.view.ViewPager>LinearLayout>

2、抽象类实现

public abstract class TabActivity extends AppCompatActivity{    private ViewPager viewPager;    private TabLayout tabLayout;    private SimpleFragmentPagerAdapter pagerAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_tab_top);        initView();    }    private void initView() {        viewPager = (ViewPager) findViewById(R.id.viewPager);        tabLayout = (TabLayout) findViewById(R.id.tabLayout);        pagerAdapter = new SimpleFragmentPagerAdapter(getSupportFragmentManager(), this);        viewPager.setAdapter(pagerAdapter);        tabLayout.setupWithViewPager(viewPager);        tabLayout.setTabMode(TabLayout.MODE_FIXED);    }    protected abstract List getFragments();//返回tab对应的fragment    protected abstract List getTitles();//头部显示的title列表    public class SimpleFragmentPagerAdapter extends FragmentPagerAdapter {        public SimpleFragmentPagerAdapter(FragmentManager fm, Context context) {            super(fm);        }        @Override        public Fragment getItem(int position) {            return getFragments().get(position);        }        @Override        public int getCount() {            return getFragments().size();        }        @Override        public CharSequence getPageTitle(int position) {            if (getTitles()!=null&&!getTitles().isEmpty()){                return getTitles().get(position);            }            return null;        }    }}

以上代码便实现了一个通用的头部文字选项卡抽象类，以后要实现类似上面图2界面只需要这样:

public class TestTopTabActivity extends TabActivity {    @Override    protected List getFragments() {        List fragments = new ArrayList();        fragments.add(BlankFragment.newInstance("1",null));        fragments.add(BlankFragment.newInstance("2",null));        fragments.add(BlankFragment.newInstance("3",null));        fragments.add(BlankFragment.newInstance("4",null));        return fragments;    }    @Override    protected List getTitles() {        List list = new ArrayList();        list.add("待支付");        list.add("待发货");        list.add("待收货");        list.add("待评价");        return list;    }}

实现一个底部自定义视图选项卡

要实现一个底部自定义视图要相对麻烦一点，因为底部的视图是由我们提供的，所以需要一个我们的自定义视图，那么怎么实现呢，我们可能想到在底部设置写一个自定义能添加底部视图的view，然后做不同的点击处理。但是TabLayout下的每个tab其实是支持设置自定义视图的，只需要调用TabLayout.Tab对象提供的setCustomView方法即可。

这样我们提供一个底部自定义视图选项卡的抽象类如下：

1、首先定义布局
activity_tab.xml

<?xml version="1.0" encoding="utf-8"?><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.v4.view.ViewPager        android:id="@+id/viewPager"        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1">android.support.v4.view.ViewPager>    <View        android:layout_width="match_parent"        android:layout_height="1dp"        android:background="#d3d3d3"        android:orientation="vertical">    View>    <android.support.design.widget.TabLayout        android:id="@+id/tabLayout"        android:layout_width="match_parent"        app:tabIndicatorHeight="0dp"        android:layout_height="48dp">android.support.design.widget.TabLayout>LinearLayout>

2、抽象类实现

public abstract class TabActivity extends AppCompatActivity{    private ViewPager viewPager;    private TabLayout tabLayout;    private SimpleFragmentPagerAdapter pagerAdapter;    private TabType mTabType = TabType.BottomCustomViewTab;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_tab);        initView();    }    private void initView() {        viewPager = (ViewPager) findViewById(R.id.viewPager);        tabLayout = (TabLayout) findViewById(R.id.tabLayout);        pagerAdapter = new SimpleFragmentPagerAdapter(getSupportFragmentManager(), this);        viewPager.setAdapter(pagerAdapter);        tabLayout.setupWithViewPager(viewPager);        tabLayout.setTabMode(TabLayout.MODE_FIXED);        if (getTabViews()!=null){            for (int i = 0; i < tabLayout.getTabCount(); i++) {                TabLayout.Tab tab = tabLayout.getTabAt(i);                tab.setCustomView(pagerAdapter.getTabView(i));            }        }    }    protected abstract List getTabViews();//返回底部自定义tab视图    protected abstract List getFragments();//返回tab对应的fragment    public class SimpleFragmentPagerAdapter extends FragmentPagerAdapter {        public SimpleFragmentPagerAdapter(FragmentManager fm, Context context) {            super(fm);        }        @Override        public Fragment getItem(int position) {            return getFragments().get(position);        }        @Override        public int getCount() {            return getFragments().size();        }        public View getTabView(int position) {            return getTabViews().get(position);        }    }}

上面代码和之前实现一个头部标题选项卡的抽象类大致一样，只是提供了 protected abstract List getTabViews()方法用于让子类提供底部自定义tab视图TabItemView，底部视图一般就是一个图片加一个文字，那么我们自定义一个底部视图TabItemView如下。

TabItemView实现如下：

public class TabItemView extends LinearLayout {    /**     * Item 的标题     */    public String title;    public int textColor;    public int iconDrawable;    public int bgDrawable;    public TextView tvTitle;    public ImageView ivIcon;    public TabItemView(Context context, String title, int textColor, int iconDrawable,                       int bgDrawable) {        super(context);        this.title = title;        this.iconDrawable = iconDrawable;        this.textColor = textColor;        this.bgDrawable = bgDrawable;        init();    }    /**     * 初始化     */    public void init(){        View view = LayoutInflater.from(super.getContext()).inflate(R.layout.view_tab_item, this);        tvTitle = (TextView) view.findViewById(R.id.tvTitle);        ivIcon = (ImageView) view.findViewById(R.id.ivIcon);        LinearLayout.LayoutParams layoutParams = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);        layoutParams.weight = 1;        view.setLayoutParams(layoutParams);        if (iconDrawable!=0){            ivIcon.setImageResource(iconDrawable);        }        if (bgDrawable!=0) {            this.setBackgroundResource(bgDrawable);        }        if (textColor!=0){            tvTitle.setTextColor(textColor);        }        tvTitle.setText(title);    }}

TabItemView对应布局：
view_tab_item.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/viewTabView"    android:orientation="vertical"    android:layout_width="match_parent"    android:background="?android:selectableItemBackground"    android:gravity="center"    android:layout_height="match_parent">    <ImageView        android:id="@+id/ivIcon"        android:layout_weight="1"        android:src="@mipmap/ic_launcher"        android:layout_width="match_parent"        android:layout_height="match_parent" />    <TextView        android:id="@+id/tvTitle"        android:layout_weight="1"        android:gravity="center"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:text="首页"/>LinearLayout>

很简单就是提供一个构造方法在初始化的时候设置图片、文字、文字颜色等信息。

那么到此，我们如果遇到如上图1要实现一个底部视图选项卡只需要这样：

public class TestBottomTabActivity extends TabActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);    }    @Override    protected List getTabViews() {        List tabviews = new ArrayList();        tabviews.add(new TabItemView(this,"1",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"2",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"3",R.color.colorPrimary,R.mipmap.ic_launcher,0));        tabviews.add(new TabItemView(this,"4",R.color.colorPrimary,R.mipmap.ic_launcher,0));        return tabviews;    }    @Override    protected List getFragments() {        List fragments = new ArrayList();        fragments.add(BlankFragment.newInstance("1",null));        fragments.add(BlankFragment.newInstance("2",null));        fragments.add(BlankFragment.newInstance("3",null));        fragments.add(BlankFragment.newInstance("4",null));        return fragments;    }}

二者结合

到此相信你们已经发现实现头部文字选项卡或者底部自定义视图选项卡这里都用了TabLayout+ViewPager的方式，那么我们来个结合。

提供一个枚举指定tab类型，根据tab类型进行数据的获取即可。
组合之后的抽象类如下：

public abstract class TabActivity extends AppCompatActivity{    private ViewPager viewPager;    private TabLayout tabLayout;    private SimpleFragmentPagerAdapter pagerAdapter;    private TabType mTabType = TabType.BottomCustomViewTab;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        mTabType = getTabType()==null?TabType.BottomCustomViewTab:getTabType();        if (mTabType==TabType.BottomCustomViewTab){            setContentView(R.layout.activity_tab);        }else{            setContentView(R.layout.activity_tab_top);        }        initView();    }    private void initView() {        viewPager = (ViewPager) findViewById(R.id.viewPager);        tabLayout = (TabLayout) findViewById(R.id.tabLayout);        pagerAdapter = new SimpleFragmentPagerAdapter(getSupportFragmentManager(), this);        viewPager.setAdapter(pagerAdapter);        tabLayout.setupWithViewPager(viewPager);        tabLayout.setTabMode(TabLayout.MODE_FIXED);        if (getTabViews()!=null){            for (int i = 0; i < tabLayout.getTabCount(); i++) {                TabLayout.Tab tab = tabLayout.getTabAt(i);                tab.setCustomView(pagerAdapter.getTabView(i));            }        }    }    protected abstract List getTabViews();//返回底部自定义tab视图    protected abstract List getFragments();//返回tab对应的fragment    protected abstract List getTitles();//头部显示的title列表    protected abstract TabType getTabType();//tab类型-分为底部tab和头部tab    public class SimpleFragmentPagerAdapter extends FragmentPagerAdapter {        public SimpleFragmentPagerAdapter(FragmentManager fm, Context context) {            super(fm);        }        @Override        public Fragment getItem(int position) {            return getFragments().get(position);        }        @Override        public int getCount() {            return getFragments().size();        }        @Override        public CharSequence getPageTitle(int position) {            if (getTitles()!=null&&!getTitles().isEmpty()){                return getTitles().get(position);            }            return null;        }        public View getTabView(int position) {            return getTabViews().get(position);        }    }    public enum TabType{//Tab类型        BottomCustomViewTab,//底部自定义tab        TopTitleTab//头部标题tab    }}

这样就实现了统一，以后不管是底部还是头部，只需要继承TabActivity之后实现相应的抽象方法即可（参考文章开头）。

结束

源码下载请点击：http://download.csdn.net/detail/yissan/9861159
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Android快速开发-选项卡

介绍