package com.example.viewpager01;
import java.util.ArrayList;
import java.util.List;


import android.app.Activity;
import android.app.LocalActivityManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;


public class MainActivity extends Activity {


private ViewPager viewPager;
private List<View> viewList;
private View view1, view2, view3;  //
//Context context = null;
LocalActivityManager manager = null;  //这里要实现把Activity转换为View
private int[] ids = { R.drawable.guide_page_1, R.drawable.guide_page_2,R.drawable.guide_page_3 };//存放图片数组，这里要实现把图片转换为View
   
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.user_lader);


manager = new LocalActivityManager(this , true);
    manager.dispatchCreate(savedInstanceState);
       
    
    viewList=new ArrayList<View>(); 
for (int i = 0; i < ids.length; i++) {
ImageView iv = new ImageView(this);
iv.setImageResource(ids[i]);
ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.FILL_PARENT);
iv.setLayoutParams(params);
iv.setScaleType(ScaleType.FIT_XY);


viewList.add(iv);
}

Intent intent = new Intent(getApplicationContext(), A.class);
viewList.add(getView("A", intent));
 


// 1,
viewPager = (ViewPager) findViewById(R.id.view_pager);



// 2,PageAdapter 必须重写的四个函数：


/*
* boolean isViewFromObject(View arg0, Object arg1) int getCount() void
* destroyItem(ViewGroup container, int position,Object object) Object
* instantiateItem(ViewGroup container, int position)
*/
viewPager.setAdapter(new PagerAdapter() {
@Override
public int getCount() {
if(viewList==null)
{
  return 0;
}
else
{
 return viewList.size();  //getCount():返回要滑动的VIew的个数
}
}


@Override
public boolean isViewFromObject(View arg0, Object arg1) {
//return arg0 == arg1;    //isViewFromObject():对于这个函数就先不做解说，大家眼下先知道它要这样重写即可了。后面我们会对它进行改写。
//System.out.println("position===isViewFromObject======"+(int)Integer.parseInt(arg1.toString())+(arg0 == viewList.get((int)Integer.parseInt(arg1.toString()))));
return arg0 == viewList.get((int)Integer.parseInt(arg1.toString()));////依据传来的key，找到view,推断与传来的參数View arg0是不是同一个视图 
}


@Override
public Object instantiateItem(ViewGroup container, int position) {
container.addView(viewList.get(position));      //做了两件事。第一：将当前视图加入到container中。第二：返回当前View
//return viewList.get(position);
//System.out.println("position===instantiateItem======"+position);
return position;  // //把当前新增视图的位置（position）作为Key传过去  
}


@Override
public void destroyItem(ViewGroup container, int position,
Object object) {   
if(position==1)
{
viewList=null;
}
else
{
 //System.out.println("position====destroyItem====="+position);
container.removeView(viewList.get(position));   //从当前container中删除指定位置（position）的View;
}
}


});
}



private View getView(String id, Intent intent) {
       return manager.startActivity(id, intent).getDecorView();
   }


}