Android中如何使用ViewPager实现类似laucher左右拖动效果源码

package com.andyidea.guidedemo; import java.util.ArrayList; import android.app.Activity; import android.os.Bundle; import android.os.Parcelable; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.support.v4.view.ViewPager.OnPageChangeListener; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.view.Window; import android.widget.ImageView; public class GuideViewDemoActivity extends Activity { private ViewPager viewPager; private ArrayList<View> pageViews; private ViewGroup main, group; private ImageView imageView; private ImageView[] imageViews; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.requestWindowFeature(Window.FEATURE_NO_TITLE); LayoutInflater inflater = getLayoutInflater(); pageViews = new ArrayList<View>(); pageViews.add(inflater.inflate(R.layout.item01, null)); pageViews.add(inflater.inflate(R.layout.item02, null)); pageViews.add(inflater.inflate(R.layout.item03, null)); pageViews.add(inflater.inflate(R.layout.item04, null)); imageViews = new ImageView[pageViews.size()]; main = (ViewGroup)inflater.inflate(R.layout.main, null); // group是R.layou.main中的负责包裹小圆点的LinearLayout. group = (ViewGroup)main.findViewById(R.id.viewGroup); viewPager = (ViewPager)main.findViewById(R.id.guidePages); for (int i = 0; i < pageViews.size(); i++) { imageView = new ImageView(GuideViewDemoActivity.this); imageView.setLayoutParams(new LayoutParams(20,20)); imageView.setPadding(20, 0, 20, 0); imageViews[i] = imageView; if (i == 0) { //默认选中第一张图片 imageViews[i].setBackgroundResource(R.drawable.page_indicator_focused); } else { imageViews[i].setBackgroundResource(R.drawable.page_indicator); } group.addView(imageViews[i]); } setContentView(main); viewPager.setAdapter(new GuidePageAdapter()); viewPager.setOnPageChangeListener(new GuidePageChangeListener()); } /** 指引页面Adapter */ class GuidePageAdapter extends PagerAdapter { @Override public int getCount() { return pageViews.size(); } @Override public boolean isViewFromObject(View arg0, Object arg1) { return arg0 == arg1; } @Override public int getItemPosition(Object object) { // TODO Auto-generated method stub return super.getItemPosition(object); } @Override public void destroyItem(View arg0, int arg1, Object arg2) { // TODO Auto-generated method stub ((ViewPager) arg0).removeView(pageViews.get(arg1)); } @Override public Object instantiateItem(View arg0, int arg1) { // TODO Auto-generated method stub ((ViewPager) arg0).addView(pageViews.get(arg1)); return pageViews.get(arg1); } @Override public void restoreState(Parcelable arg0, ClassLoader arg1) { // TODO Auto-generated method stub } @Override public Parcelable saveState() { // TODO Auto-generated method stub return null; } @Override public void startUpdate(View arg0) { // TODO Auto-generated method stub } @Override public void finishUpdate(View arg0) { // TODO Auto-generated method stub } } /** 指引页面改监听器 */ class GuidePageChangeListener implements OnPageChangeListener { @Override public void onPageScrollStateChanged(int arg0) { // TODO Auto-generated method stub } @Override public void onPageScrolled(int arg0, float arg1, int arg2) { // TODO Auto-generated method stub } @Override public void onPageSelected(int arg0) { for (int i = 0; i < imageViews.length; i++) { imageViews[arg0] .setBackgroundResource(R.drawable.page_indicator_focused); if (arg0 != i) { imageViews[i] .setBackgroundResource(R.drawable.page_indicator); } } } } }