低版本系统兼容的ActionBar（四）添加Tab+添加自定义的Tab视图+Fragment

在ActionBar中添加Tab是很有用的技巧。在support V7库的支持下，我们几乎可以用和之前一样的方式来添加Tab，对于Tab来说，我们可以和MenuItem一样，给他定义自己的视图。我这里定义了个进度条，主要是来说明这个问题。本系列的博文也将接近尾声了，后面就是个定义ActionBar样式和一个仿照微信的实例，顺便讲解下Fragment和ViewPager的用法。

activity_main.xml（定义了一个FrameLayout来准备存放Fragment）

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.kale.actionbar03.MainActivity" >

    <FrameLayout

        android:id="@+id/container_id"

        android:layout_width="match_parent"

        android:layout_height="match_parent" />

</RelativeLayout>

tab_custom_view.xml（自定义的Tab视图）

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent">

    <ProgressBar

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:indeterminate="true"/>

</LinearLayout>

MainActivity.java

package com.kale.actionbar03;

import android.os.Bundle;

import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentTransaction;

import android.support.v7.app.ActionBar;

import android.support.v7.app.ActionBar.Tab;

import android.support.v7.app.ActionBarActivity;

import android.widget.Toast;

public class MainActivity extends ActionBarActivity implements ActionBar.TabListener{

    ActionBar actionBar;

    private static final String SELECTED_ITEM = "selected_item";

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        actionBar = getSupportActionBar();

        //actionbar.setDisplayShowHomeEnabled(false);

        //actionbar.setDisplayShowTitleEnabled(false);//定义这两行后就会没有标题栏，只有tab栏了

        //设定有Tab

        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        ActionBar.Tab tab;

        //开始添加Tab

        for (int i = 1; i <= 3; i++) {

            tab = actionBar.newTab();

            tab.setText("Tab " + i);

            tab.setTabListener(this);

            actionBar.addTab(tab);

        }

        tab = actionBar.newTab();

        tab.setCustomView(R.layout.tab_custom_view);

        tab.setText("x");

        tab.setTabListener(this);

        actionBar.addTab(tab);

    }

    @Override

    protected void onRestoreInstanceState(Bundle savedInstanceState) {

        super.onRestoreInstanceState(savedInstanceState);

        if (savedInstanceState.containsKey(SELECTED_ITEM)) {

            //选中前面保存的索引对应的Fragment页

            actionBar.setSelectedNavigationItem(savedInstanceState.getInt(SELECTED_ITEM));

        }

    }

    @Override

    protected void onSaveInstanceState(Bundle outState) {

        //将当前选中的fragment页的索引保存到Bundle中

        outState.putInt(SELECTED_ITEM, actionBar.getSelectedNavigationIndex());

        super.onSaveInstanceState(outState);

    }

    /*

     * @see android.support.v7.app.ActionBar.TabListener#onTabReselected(android.support.v7.app.ActionBar.Tab, android.support.v4.app.FragmentTransaction)

     * Tab再次被选中的时候执行的方法

     */

    @Override

    public void onTabReselected(Tab tab, FragmentTransaction transaction) {

    }

    @Override

    public void onTabSelected(Tab tab, FragmentTransaction transaction) {

        Toast.makeText(getApplicationContext(), tab.getText(), 0).show();

        //创建一个新的Fragment的对象

        Fragment fragment = new DummyFragment();

        //创建一个Bundle对象，用于向Fragment传入参数

        Bundle bundle = new Bundle();

        bundle.putInt(DummyFragment.BUNDLE_SECTION_NUMBER, tab.getPosition()+1);

        //向Fragment传入参数

        fragment.setArguments(bundle);

        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();

        //使用fragment

        ft.replace(R.id.container_id, fragment);

        ft.commit();

    } 

    @Override

    public void onTabUnselected(Tab tab, FragmentTransaction transaction) {

    }

}

DummyFragment.java

package com.kale.actionbar03;

import android.os.Bundle;

import android.support.annotation.Nullable;

import android.support.v4.app.Fragment;

import android.view.Gravity;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.TextView;

public class DummyFragment extends Fragment {

    public static final String BUNDLE_SECTION_NUMBER = "section_number";

    // 该返回值就是这个Fragment显示的view组件

    @Override

    public View onCreateView(LayoutInflater inflater,

            @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        super.onCreateView(inflater, container, savedInstanceState);

        TextView textView = new TextView(getActivity());

        textView.setGravity(Gravity.CENTER);

        // 获取创建该Fragment时传入的参数的Bundle

        Bundle bundle = getArguments();

        textView.setText("Fragment 0" + bundle.getInt(BUNDLE_SECTION_NUMBER));

        textView.setTextSize(50);

        return textView;

    }

}

源码下载：http://download.****.net/detail/shark0017/7688459