开源项目PullToRefresh详解（四）——PullToRefreshListView和ViewPager的结合使用

　　其实这个不是什么新东西了，在介绍（一）中我们就知道了PullToRefreshListView的用法，这里只要将其放入到ViewPager中就行啦。ViewPager还是和以往一样的定义和使用，在适配器中存视图的时候放入PullToRefreshListView就行。

1.ViewPager的布局文件

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    android:background="#000000">

    <!-- The PullToRefreshListView replaces a standard ListView widget. -->

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

</LinearLayout>

2.找到ViewPager并设置适配器

private void initViewPager() {
        // TODO 自动生成的方法存根
        mViewPager = (ViewPager) findViewById(R.id.vp_list);
        //得到设置好的view列表
        ArrayList<View> viewList = setListViewInVp();
        mViewPager.setAdapter(new ListViewPagerAdapter(viewList));
    }

适配器：

    /**
     * @author:Jack Tony
     * @tips  :viewPager的适配器
     * @date  :2014-10-14
     */
    public class ListViewPagerAdapter extends PagerAdapter {
        //设置list数组，传入view
        private ArrayList<View> mViewList;
        private int pagerNum = 0;

        public ListViewPagerAdapter(ArrayList<View> viewList) {
            mViewList = viewList;
        }

        public int getPagerNum() {
            return pagerNum;
        }

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

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }

        @Override
        public void destroyItem(View arg0, int position, Object object) {
            if (mViewList.get(position) != null) {
                ((ViewPager) arg0).removeView(mViewList.get(position));
            }
        }

        @Override
        public Object instantiateItem(View container, int position) {
            try {
                if (mViewList.get(position).getParent() == null) {
                    ((ViewPager) container).addView(mViewList.get(position), 0);
                } else {
                    /*
                     * 很难理解新添加进来的view会自动绑定一个父类，由于一个儿子view不能与两个父类相关，
                     * 所以得解绑不这样做否则会产生 viewpager java.lang.IllegalStateException:
                     * The specified child already has a parent. You must call
                     * removeView() on the child's parent first.
                     */
                    ((ViewGroup) mViewList.get(position).getParent())
                            .removeView(mViewList.get(position));
                    ((ViewPager) container).addView(mViewList.get(position), 0);
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                pagerNum = position;
            }
            return mViewList.get(position);
        }

    }

3.开始设置要放入viewPager中的listView

布局文件：

layout_listview_in_viewpager.xml

<?xml version="1.0" encoding="utf-8"?>
<com.handmark.pulltorefresh.library.PullToRefreshListView 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ptr="http://schemas.android.com/apk/res-auto"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    ptr:ptrHeaderBackground="@android:color/darker_gray" />

java代码：

    private ArrayList<View> setListViewInVp() {
        //设置给viewpager中填充的view列表
        ArrayList<View> viewList = new ArrayList<View>();
        //将string数组放入适配器中
        final String[] data = { "1", "2", "3","4", "5", "6", "7", "8", "9", "10", "11",
            "12", "13", "14", "15", "16", "17","18", "19", "20",  };
        ListAdapter adapter = new ArrayAdapter<String>(getApplicationContext(), 
                android.R.layout.simple_list_item_1, data);
        
        //找到listView的布局，生成可以下拉刷新的listView，添加到视图列表中
        LayoutInflater inflater = LayoutInflater.from(getApplication());
        for (int i = 0; i < 4; i++) {
            PullToRefreshListView plv = (PullToRefreshListView) inflater.inflate(
                    R.layout.layout_listview_in_viewpager,  null);
            plv.setAdapter(adapter);
            plv.setOnRefreshListener(new OnRefreshListener<ListView>() {

                @Override
                public void onRefresh(PullToRefreshBase<ListView> refreshView) {
                    // TODO 自动生成的方法存根
                    new GetDataTask(refreshView).execute();
                }
            });
            
            viewList.add(plv);
        }
        return viewList;
    }
    

4.定义异步任务

    private static class GetDataTask extends AsyncTask<Void, Void, Void> {

        PullToRefreshBase<?> mRefreshedView;

        public GetDataTask(PullToRefreshBase<?> refreshedView) {
            mRefreshedView = refreshedView;
        }

        @Override
        protected Void doInBackground(Void... params) {
            // Simulates a background job.
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            mRefreshedView.onRefreshComplete();
            super.onPostExecute(result);
        }
    }

MainActivity.java的全部代码

package com.example.ptrlistviewinviewpagertest;

import java.util.ArrayList;

import android.app.Activity;
import android.os.AsyncTask;
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.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;

import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

public class MainActivity extends Activity {
    
    private ViewPager mViewPager;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        initView();
    }

    private void initView() {
        // TODO 自动生成的方法存根
        initViewPager();
    }

    private void initViewPager() {
        // TODO 自动生成的方法存根
        mViewPager = (ViewPager) findViewById(R.id.vp_list);
        //得到设置好的view列表
        ArrayList<View> viewList = setListViewInVp();
        mViewPager.setAdapter(new ListViewPagerAdapter(viewList));
    }
    
    private ArrayList<View> setListViewInVp() {
        //设置给viewpager中填充的view列表
        ArrayList<View> viewList = new ArrayList<View>();
        //将string数组放入适配器中
        final String[] data = { "1", "2", "3","4", "5", "6", "7", "8", "9", "10", "11",
            "12", "13", "14", "15", "16", "17","18", "19", "20",  };
        ListAdapter adapter = new ArrayAdapter<String>(getApplicationContext(), 
                android.R.layout.simple_list_item_1, data);
        
        //找到listView的布局，生成可以下拉刷新的listView，添加到视图列表中
        LayoutInflater inflater = LayoutInflater.from(getApplication());
        for (int i = 0; i < 4; i++) {
            PullToRefreshListView plv = (PullToRefreshListView) inflater.inflate(
                    R.layout.layout_listview_in_viewpager,  null);
            plv.setAdapter(adapter);
            plv.setOnRefreshListener(new OnRefreshListener<ListView>() {

                @Override
                public void onRefresh(PullToRefreshBase<ListView> refreshView) {
                    // TODO 自动生成的方法存根
                    new GetDataTask(refreshView).execute();
                }
            });
            
            viewList.add(plv);
        }
        return viewList;
    }
    
    /**
     * @author:Jack Tony
     * @tips  :viewPager的适配器
     * @date  :2014-10-14
     */
    public class ListViewPagerAdapter extends PagerAdapter {
        //设置list数组，传入view
        private ArrayList<View> mViewList;
        private int pagerNum = 0;

        public ListViewPagerAdapter(ArrayList<View> viewList) {
            mViewList = viewList;
        }

        public int getPagerNum() {
            return pagerNum;
        }

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

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;
        }

        @Override
        public void destroyItem(View arg0, int position, Object object) {
            if (mViewList.get(position) != null) {
                ((ViewPager) arg0).removeView(mViewList.get(position));
            }
        }

        @Override
        public Object instantiateItem(View container, int position) {
            try {
                if (mViewList.get(position).getParent() == null) {
                    ((ViewPager) container).addView(mViewList.get(position), 0);
                } else {
                    /*
                     * 很难理解新添加进来的view会自动绑定一个父类，由于一个儿子view不能与两个父类相关，
                     * 所以得解绑不这样做否则会产生 viewpager java.lang.IllegalStateException:
                     * The specified child already has a parent. You must call
                     * removeView() on the child's parent first.
                     */
                    ((ViewGroup) mViewList.get(position).getParent())
                            .removeView(mViewList.get(position));
                    ((ViewPager) container).addView(mViewList.get(position), 0);
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                pagerNum = position;
            }
            return mViewList.get(position);
        }

    }
    
    private static class GetDataTask extends AsyncTask<Void, Void, Void> {

        PullToRefreshBase<?> mRefreshedView;

        public GetDataTask(PullToRefreshBase<?> refreshedView) {
            mRefreshedView = refreshedView;
        }

        @Override
        protected Void doInBackground(Void... params) {
            // Simulates a background job.
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            mRefreshedView.onRefreshComplete();
            super.onPostExecute(result);
        }
    }
}

源码下载：http://download.csdn.net/detail/shark0017/8036901