Android-PullToRefresh开源项目的使用

Posted 2022-09-22 Veer Han

本案例基于上一个案例
PullToRefresh开源项目导入eclipse的方法
1.将activity_main.xml中的ListView控件换成开源项目中的PullToRefreshListView控件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="$relativePackage.$activityClass" >

    <com.handmark.pulltorefresh.library.PullToRefreshListView
        android:id="@+id/pull_to_refresh_listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

2.修改MainActivity.java

package com.example.pulldemo;

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

import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.ListView;

import com.example.dbhytc.adapter.UserAdapter;
import com.example.dbhytc.dao.UserDao;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

public class MainActivity extends Activity 

    // 声明控件
    private PullToRefreshListView lv_users;

    private UserDao userDao;
    private List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();

    private int nowpage = 1;

    private boolean isLastRow = false;

    private UserAdapter adapter;

    private int pages;

    @SuppressLint("NewApi")
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 获取 控件对象
        lv_users = (PullToRefreshListView) findViewById(R.id.pull_to_refresh_listview);

        // 数据
        userDao = new UserDao(data, this);
        // 查询出总页数
        pages = userDao.getPages();
        userDao.getObjects(nowpage);

        adapter = new UserAdapter(this, data);

        // 设置适配器
        lv_users.setAdapter(adapter);

        lv_users.setOnRefreshListener(new OnRefreshListener<ListView>() 
            @Override
            public void onRefresh(PullToRefreshBase<ListView> refreshView) 

                // Do work to refresh the list here.
                 new GetDataTask().execute();

                // pages = userDao.getPages();

            
        );

    

    /**
     * 同步工作任务
     * 上拉 看看有没有
     * @author Administrator
     *
     */
    private class GetDataTask extends AsyncTask<Void, Void, String[]> 

        @Override
        protected void onPostExecute(String[] result) 
            if (nowpage < pages) 
                // 让当前页加上1
                nowpage = nowpage + 1;
                // 假设往这个集合中添加数据
                userDao.getObjects(nowpage);
                // 通知变化
                adapter.notifyDataSetChanged();

            
            lv_users.onRefreshComplete();
            super.onPostExecute(result);
        

        @Override
        protected String[] doInBackground(Void... params) 
            // TODO Auto-generated method stub
            return null;
        
    

3.运行该项目同样可以实现上一案例的功能。这里提供上拉刷新、下拉刷新的操作实现，即在activity_main.xml的pulltofreshListView中添加以下两行红色框中的代码

附：更详细的讲解请点击此链接。