ViewPager的實現：動態添加RadioButton

這裏我們通過向RadioGroup中動態添加RadioButton給ViewPager添加tag，然後在確定ViewPager的頁數，再通過Fragment

填充ViewPager。

activity_main.xml文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <RadioGroup
        android:id="@+id/radioGroup_tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
    </RadioGroup>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="#0373b4" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

選擇器selector：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/bg_tab" android:state_checked="true"/>
    <item android:drawable="@android:color/white" android:state_checked="false"/>

</selector>

數組資源：

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

    <string-array name="arrTabTitles">
        <item>書籤1</item>
        <item>書籤2</item>
        <item>書籤3</item>
        <item>書籤4</item>
        <item>書籤5</item>
        <item>書籤6</item>
    </string-array>

</resources>

MainActivity：繼承的是FragmentActivity 

package com.steven.tab3.fragmentradiogroupviewpager;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.Gravity;
import android.view.Menu;
import android.widget.LinearLayout.LayoutParams;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

public class MainActivity extends FragmentActivity {
	private ViewPager viewPager_main;
	private RadioGroup radioGroup_tabs;
	private RadioButton[] arrRadioButton;
	private List<Fragment> totalList = new ArrayList<Fragment>();

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//初始化選項卡
		initTabs();
		//初始化ViewPager
		intiViewPager();
	}

	/**
	 *  初始化書籤選項卡
	 */
	private void initTabs() {
		radioGroup_tabs = (RadioGroup) findViewById(R.id.radioGroup_tabs);
		//獲取我們定義的數組資源
		String[] arrTabTitles = getResources().getStringArray(
				R.array.arrTabTitles);
		//
		arrRadioButton = new RadioButton[arrTabTitles.length];
		//根據我們資源數組的長度動態創建RadioButton添加到RadioGroup中
		for (int i = 0; i < arrTabTitles.length; i++) {
			//動態創建RadioButton對象
			RadioButton radioButton = new RadioButton(this);
			//設置文本
			radioButton.setText(arrTabTitles[i]);
			//設置位置
			radioButton.setGravity(Gravity.CENTER);
			//設置背景
			radioButton.setButtonDrawable(R.drawable.partition);
			//通過選擇器給RadioButton設置背景，包括點擊時的背景和未被點擊時的背景
			radioButton.setBackgroundResource(R.drawable.bg_radiobutton);
			// 獲取屏幕寬度
			int screenWidth = getResources().getDisplayMetrics().widthPixels;
			//獲取每個tag的寬度
			int eachWidth = screenWidth / arrTabTitles.length;
			//設置每個條目的寬度和高度，寬度就是上面得到的平均值，高度是包裹內容
			LayoutParams params = new LayoutParams(eachWidth,
					LayoutParams.WRAP_CONTENT);
			//給RadioButton設置寬度和高度，通過params設置
			radioButton.setLayoutParams(params);
			//把我們動態創建
			radioGroup_tabs.addView(radioButton);
			arrRadioButton[i] = radioButton;
		}
		//默認RadioButton數組的第0個位置爲選中
		arrRadioButton[0].setChecked(true);
		//設置RadioGroup的點擊事件
		radioGroup_tabs
				.setOnCheckedChangeListener(new OnCheckedChangeListener() {
					@Override
					public void onCheckedChanged(RadioGroup group, int checkedId) {
						//遍歷RadioGroup，如果RadioButton數組中的RadioButton的id和當前選中的id一樣，就設置ViewPager的位置爲
						//該RadioButton所對應的ViewPager
						for (int i = 0; i < radioGroup_tabs.getChildCount(); i++) {
							if (arrRadioButton[i].getId() == checkedId) {
								viewPager_main.setCurrentItem(i);
							}
						}
					}
				});
	}

	/**
	 * 初始化ViewPager
	 */
	private void intiViewPager() {
		viewPager_main = (ViewPager) findViewById(R.id.viewPager_main);
		// 初始化數據totalList,通過RadioGroup的子類長度明確ViewPager的頁數
		for (int i = 0; i < radioGroup_tabs.getChildCount(); i++) {
			//調用DummyFragment的getInstance方法，其返回值爲一個DummyFragment對象
			DummyFragment fragment = DummyFragment.getInstance(i + 1);
			//把我們實例化的Fragment放入lists集合中
			totalList.add(fragment);
		}
		// 給ViewPager設置適配器
		viewPager_main.setAdapter(new MyPagerAdapter(
				getSupportFragmentManager(), totalList));
		// 給ViewPager設置監聽事件
		viewPager_main.setOnPageChangeListener(new OnPageChangeListener() {

			@Override
			public void onPageSelected(int position) {
				//當頁面被選中時，設置RadioButton顯示下面的藍色橫線，就是我們selector選擇器中定義的
				arrRadioButton[position].setChecked(true);
			}

			@Override
			public void onPageScrolled(int arg0, float arg1, int arg2) {
				// TODO Auto-generated method stub

			}

			@Override
			public void onPageScrollStateChanged(int arg0) {
				// TODO Auto-generated method stub

			}
		});
	}

	/**
	 * 創建自定義適配器
	 * 
	 * @author Administrator
	 * 
	 */
	class MyPagerAdapter extends FragmentPagerAdapter {
		private List<Fragment> list = null;

		public MyPagerAdapter(FragmentManager fm, List<Fragment> list) {
			super(fm);
			this.list = list;
		}

		@Override
		public Fragment getItem(int position) {
			return list.get(position);
		}

		@Override
		public int getCount() {
			return list.size();
		}
	}

}

繼承自ListFragment的MyFragment：

package com.steven.tab3.fragmentradiogroupviewpager;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.widget.SimpleAdapter;

public class DummyFragment extends ListFragment {
	private final static String KEY_NAME = "tabindex";
	private int tabindex = 0;
	private List<Map<String, Object>> totalList = new ArrayList<Map<String, Object>>();

	@Override
	public void onActivityCreated(Bundle savedInstanceState) {
		super.onActivityCreated(savedInstanceState);
		// 數據初始化。一般來說數據都來自於網絡，需要異步訪問，json解析
		loadNetworkData();
		// 創建適配器
		SimpleAdapter adapter = new SimpleAdapter(getActivity(), totalList,
				R.layout.item_dummyframent, new String[] { "iconId", "title",
						"summary" }, new int[] { R.id.imageView_item_icon,
						R.id.textView_item_title, R.id.textView_item_summary });
		// 設置適配器
		setListAdapter(adapter);
	}
	/**
	 * 創建一個靜態方法讓MainActivity調用，感覺沒有必要
	 * 其實直接在MainActivity中new對象就可以了
	 * @param tabindex
	 * @return
	 */
	public static DummyFragment getInstance(int tabindex) {
		DummyFragment fragment = new DummyFragment();
		Bundle bundle = new Bundle();
		bundle.putInt(KEY_NAME, tabindex);
		fragment.setArguments(bundle);
		return fragment;
	}

	/**
	 * 初始化totalList集合，就是我們把我們要加載的數據放入List集合中
	 */
	private void loadNetworkData() {
		tabindex = getArguments().getInt(KEY_NAME);
		for (int i = 0; i < 20; i++) {
			Map<String, Object> map = new HashMap<String, Object>();
			map.put("iconId", R.drawable.ic_180);
			map.put("title", "title_" + tabindex + "_" + i);
			map.put("summary", "summay_" + tabindex + "_" + i);
			totalList.add(map);
		}
	}
}

運行結果：