（转）ViewPager使用

package com.example.testviewpagerandtabhost;

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


import android.os.Bundle;
import android.os.Parcelable;
import android.app.Activity;
import android.app.LocalActivityManager;
import android.content.Context;
import android.content.Intent;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.util.DisplayMetrics;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TextView;

public class MainActivity extends Activity {

	Context context = null;
	LocalActivityManager manager = null;
	ViewPager pager = null;
	TextView t1,t2,t3;
	
	private int offset = 0;// 动画图片偏移量
	private int currIndex = 0;// 当前页卡编号
	private int bmpW;// 动画图片宽度
	private ImageView cursor;// 动画图片

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		context = MainActivity.this;
		manager = new LocalActivityManager(this , true);
		manager.dispatchCreate(savedInstanceState);

		InitImageView();
		initTextView();
		initPagerViewer();

	}
	/**
	 * 初始化标题
	 */
	private void initTextView() {
		t1 = (TextView) findViewById(R.id.text1);
		t2 = (TextView) findViewById(R.id.text2);
		t3 = (TextView) findViewById(R.id.text3);

		t1.setOnClickListener(new MyOnClickListener(0));
		t2.setOnClickListener(new MyOnClickListener(1));
		t3.setOnClickListener(new MyOnClickListener(2));
		
	}
	/**
	 * 初始化PageViewer
	 */
	private void initPagerViewer() {
		pager = (ViewPager) findViewById(R.id.viewpage);
		final ArrayList<View> list = new ArrayList<View>();
		Intent intent = new Intent(context, A.class);
		list.add(getView("A", intent));
		Intent intent2 = new Intent(context, B.class);
		list.add(getView("B", intent2));
		Intent intent3 = new Intent(context, C.class);
		list.add(getView("C", intent3));

		pager.setAdapter(new MyPagerAdapter(list));
		pager.setCurrentItem(0);
		pager.setOnPageChangeListener(new MyOnPageChangeListener());
	}
	/**
	 * 初始化动画
	 */
	private void InitImageView() {
		cursor = (ImageView) findViewById(R.id.cursor);
		bmpW = BitmapFactory.decodeResource(getResources(), R.drawable.roller)
		.getWidth();// 获取图片宽度
		DisplayMetrics dm = new DisplayMetrics();
		getWindowManager().getDefaultDisplay().getMetrics(dm);
		int screenW = dm.widthPixels;// 获取分辨率宽度
		offset = (screenW / 3 - bmpW) / 2;// 计算偏移量
		Matrix matrix = new Matrix();
		matrix.postTranslate(offset, 0);
		cursor.setImageMatrix(matrix);// 设置动画初始位置
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.activity_main, menu);
		return true;
	}
	/**
	 * 通过activity获取视图
	 * @param id
	 * @param intent
	 * @return
	 */
	private View getView(String id, Intent intent) {
		return manager.startActivity(id, intent).getDecorView();
	}

	/**
	 * Pager适配器
	 */
	public class MyPagerAdapter extends PagerAdapter{
		List<View> list =  new ArrayList<View>();
		public MyPagerAdapter(ArrayList<View> list) {
			this.list = list;
		}

		@Override
		public void destroyItem(ViewGroup container, int position,
				Object object) {
			ViewPager pViewPager = ((ViewPager) container);
			pViewPager.removeView(list.get(position));
		}

		@Override
		public boolean isViewFromObject(View arg0, Object arg1) {
			return arg0 == arg1;
		}

		@Override
		public int getCount() {
			return list.size();
		}
		@Override
		public Object instantiateItem(View arg0, int arg1) {
			ViewPager pViewPager = ((ViewPager) arg0);
			pViewPager.addView(list.get(arg1));
			return list.get(arg1);
		}

		@Override
		public void restoreState(Parcelable arg0, ClassLoader arg1) {

		}

		@Override
		public Parcelable saveState() {
			return null;
		}

		@Override
		public void startUpdate(View arg0) {
		}
	}
	/**
	 * 页卡切换监听
	 */
	public class MyOnPageChangeListener implements OnPageChangeListener {

		int one = offset * 2 + bmpW;// 页卡1 -> 页卡2 偏移量
		int two = one * 2;// 页卡1 -> 页卡3 偏移量
		//计算动态图片的位置并设置
		@Override
		public void onPageSelected(int arg0) {
			Animation animation = null;
			switch (arg0) {
			case 0:
				if (currIndex == 1) {
					animation = new TranslateAnimation(one, 0, 0, 0);
				} else if (currIndex == 2) {
					animation = new TranslateAnimation(two, 0, 0, 0);
				}
				break;
			case 1:
				if (currIndex == 0) {
					animation = new TranslateAnimation(offset, one, 0, 0);
				} else if (currIndex == 2) {
					animation = new TranslateAnimation(two, one, 0, 0);	
				}
				break;
			case 2:
				if (currIndex == 0) {
					animation = new TranslateAnimation(offset, two, 0, 0);
				} else if (currIndex == 1) {
					animation = new TranslateAnimation(one, two, 0, 0);
				}
				break;
			}
			currIndex = arg0;
			animation.setFillAfter(true);// True:图片停在动画结束位置
			animation.setDuration(300);
			cursor.startAnimation(animation);
		}

		@Override
		public void onPageScrollStateChanged(int arg0) {
			 //状态有三个0空闲，1是增在滑行中，2目标加载完毕
			//public static final int SCROLL_STATE_IDLE = 0;
			//public static final int SCROLL_STATE_DRAGGING = 1;
			//public static final int SCROLL_STATE_SETTLING = 2;

		}
		//从页面1滚动到2的过程
		@Override
		public void onPageScrolled(int arg0, float arg1, int arg2) {
			
		}
	}
	/**
	 * 头标点击监听
	 */
	public class MyOnClickListener implements View.OnClickListener {
		private int index = 0;

		public MyOnClickListener(int i) {
			index = i;
		}

		@Override
		public void onClick(View v) {
			pager.setCurrentItem(index);
		}
	};
}

主要时获取不同intent的视图。。 然后切换的的时候，将该视图增加到ViewPager中，切换下一个的时候移除本ViewPager。