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.csdn.net/detail/shark0017/7688459