使用ViewPager实现高仿launcher拖动效果.rar

package cn.com.karl.viewpager; 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 MainActivity extends Activity { ViewPager viewPager; ArrayList<View> list; ViewGroup main, group; ImageView imageView; ImageView[] imageViews; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.requestWindowFeature(Window.FEATURE_NO_TITLE); LayoutInflater inflater = getLayoutInflater(); list = new ArrayList<View>(); list.add(inflater.inflate(R.layout.item1, null)); list.add(inflater.inflate(R.layout.item2, null)); list.add(inflater.inflate(R.layout.item3, null)); list.add(inflater.inflate(R.layout.item4, null)); list.add(inflater.inflate(R.layout.item5, null)); imageViews = new ImageView[list.size()]; ViewGroup main = (ViewGroup) inflater.inflate(R.layout.main, null); // group是R.layou.main中的负责包裹小圆点的LinearLayout. ViewGroup group = (ViewGroup) main.findViewById(R.id.viewGroup); viewPager = (ViewPager) main.findViewById(R.id.viewPager); for (int i = 0; i < list.size(); i++) { imageView = new ImageView(MainActivity.this); imageView.setLayoutParams(new LayoutParams(10,10)); imageView.setPadding(10, 0, 10, 0); imageViews[i] = imageView; if (i == 0) { // 默认进入程序后第一张图片被选中; imageViews[i].setBackgroundResource(R.drawable.guide_dot_white); } else { imageViews[i].setBackgroundResource(R.drawable.guide_dot_black); } group.addView(imageView); } setContentView(main); viewPager.setAdapter(new MyAdapter()); viewPager.setOnPageChangeListener(new MyListener()); } class MyAdapter extends PagerAdapter { @Override public int getCount() { return list.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(list.get(arg1)); } @Override public Object instantiateItem(View arg0, int arg1) { // TODO Auto-generated method stub ((ViewPager) arg0).addView(list.get(arg1)); return list.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 } } class MyListener 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.guide_dot_white); if (arg0 != i) { imageViews[i] .setBackgroundResource(R.drawable.guide_dot_black); } } } } }