Android开发之底部导航栏标准

以下是封装的库源码：

package com.example.oldtab;

import java.util.ArrayList;

import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.support.v4.app.FragmentTabHost;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.TabHost;
import android.widget.TextView;

public class NsFragmentTabHost implements TabHost.OnTabChangeListener {
    private FragmentTabHost fragmentTabHost;
    private LayoutInflater layoutInflater;
    private Resources resources;
    private ArrayList<NsFragmentItem> tabs;
    private NsFragmentItem preItem;

    NsFragmentTabHost(FragmentTabHost tabhost, ActionBarActivity activity) {
        this(tabhost, activity, android.R.id.tabcontent);
    }

    NsFragmentTabHost(FragmentTabHost tabhost, ActionBarActivity activity,
            int realContentid) {
        fragmentTabHost = tabhost;
        tabs = new ArrayList<NsFragmentItem>();
        layoutInflater = activity.getLayoutInflater();
        resources = activity.getResources();
        tabhost.setup(activity.getBaseContext(),
                activity.getSupportFragmentManager(), realContentid);
        tabhost.setOnTabChangedListener(this);
    }

    public View newTabView(int layoutid, int backgroung, String title) {
        TextView tv = (TextView) layoutInflater.inflate(layoutid, null);
        tv.setText(title);
        Drawable draw = resources.getDrawable(backgroung);
        tv.setCompoundDrawablesWithIntrinsicBounds(null, draw, null, null);
        return tv;
    }

    public void AddTab(NsFragmentItem item) {
        tabs.add(item);
        fragmentTabHost.addTab(fragmentTabHost.newTabSpec(item.tag)
                .setIndicator(item.view), item.fragment, null);
    }

    public NsFragmentItem getTabByTag(String tag) {
        for (NsFragmentItem item : tabs) {
            if (item.tag == tag) {
                return item;
            }
        }
        return null;
    }

    @Override
    public void onTabChanged(String tabId) {
        NsFragmentItem item = getTabByTag(tabId);
        if (item != null) {
            if (preItem != null) {
                preItem.view.setBackgroundResource(preItem.upStyle);
            }
            preItem = item;
            item.view.setBackgroundResource(item.downStyle);
        }
    }

    public static class NsFragmentItem {
        public View view;
        public String tag;
        public Class<?> fragment;
        public int downStyle;
        public int upStyle;
    }
}

下面就是示例，如何使用上面的库

package com.example.oldtab;

import android.os.Bundle;
import android.support.v4.app.FragmentTabHost;
import android.support.v7.app.ActionBarActivity;
import android.view.View;

import com.example.oldtab.NsFragmentTabHost.NsFragmentItem;

public class Main extends ActionBarActivity {

    private static final String TAG_PERSON = "person";
    private static final String TAG_GROUP = "group";
    private static final String TAG_SETTING = "setting";

    private NsFragmentTabHost nsTabHost;
    private FragmentTabHost tabHost;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
        nsTabHost = new NsFragmentTabHost(tabHost, this, R.id.realtabcontent);
        View i1 = nsTabHost.newTabView(R.layout.tabitem,
                R.drawable.ic_action_person, "个人");
        View i2 = nsTabHost.newTabView(R.layout.tabitem,
                R.drawable.ic_action_group, "集体");
        View i3 = nsTabHost.newTabView(R.layout.tabitem,
                R.drawable.ic_action_settings, "设置");
        NsFragmentItem item1 = new NsFragmentItem();
        item1.view = i1;
        item1.tag = TAG_PERSON;
        item1.fragment = PersonFragment.class;
        item1.downStyle = R.drawable.tab_spec_down;
        item1.upStyle = R.drawable.tab_spec_nomal;
        NsFragmentItem item2 = new NsFragmentItem();
        item2.view = i2;
        item2.tag = TAG_GROUP;
        item2.fragment = GroupFragment.class;
        item2.downStyle = R.drawable.tab_spec_down;
        item2.upStyle = R.drawable.tab_spec_nomal;
        NsFragmentItem item3 = new NsFragmentItem();
        item3.view = i3;
        item3.tag = TAG_SETTING;
        item3.fragment = SettingFragment.class;
        item3.downStyle = R.drawable.tab_spec_down;
        item3.upStyle = R.drawable.tab_spec_nomal;
        nsTabHost.AddTab(item1);
        nsTabHost.AddTab(item2);
        nsTabHost.AddTab(item3);
    }
}