PullToRefreshListView 刷新

最新推荐文章于 2018-11-20 21:17:37 发布

原创最新推荐文章于 2018-11-20 21:17:37 发布 · 370 阅读

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本文介绍了一个使用 PullToRefreshListView 控件实现下拉刷新和上拉加载更多功能的 Android 应用示例。通过 AsyncTask 异步获取网络数据，并使用 Gson 进行 JSON 解析。

这是 xml文件

<?xml version="1.0" encoding="utf-8"?>
<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"
   >
    <com.handmark.pulltorefresh.library.PullToRefreshListView
        xmlns:ptr="http://schemas.android.com/apk/res-auto"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:id="@+id/refresh_list_view"
        ptr:ptrDrawable="@drawable/default_ptr_flip"
        ptr:ptrAnimationStyle="flip"
        ptr:ptrHeaderBackground="#383838"
        ptr:ptrHeaderTextColor="#FFFFFF"/>

</RelativeLayout>

Mainactivity 主界面

package com.example.liuhuan20171019;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.ListView;

import com.google.gson.Gson;
import com.handmark.pulltorefresh.library.ILoadingLayout;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
   private List<DataDataBean.NewslistBean>list=new ArrayList<>();
    private PullToRefreshListView refresh_list_view;
    private ILoadingLayout startLabels;
    private ILoadingLayout endLabels;
    private int page = 1;
    private MyAdapter myAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        refresh_list_view = (PullToRefreshListView) findViewById(R.id.refresh_list_view);
        getData();
        refresh_list_view.setMode(PullToRefreshBase.Mode.BOTH);
        startLabels = refresh_list_view.getLoadingLayoutProxy(true, false);
        startLabels.setPullLabel("下拉刷新");
        startLabels.setRefreshingLabel("正在刷新...");
        startLabels.setReleaseLabel("放开刷新");


        endLabels = refresh_list_view.getLoadingLayoutProxy(false, true);
        endLabels.setPullLabel("上拉刷新");
        endLabels.setRefreshingLabel("正在载入...");
        endLabels.setReleaseLabel("放开刷新...");
      refresh_list_view.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<ListView>() {
          @Override
          public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {
              getRefreshData();
          }

          @Override
          public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {
             page++;
                 getData();
              refresh_list_view.onRefreshComplete();
          }
      });


    }


    private void getRefreshData() {
        AsyncTask<Void, Void, String> asyncTask = new AsyncTask<Void, Void, String>() {
            @Override
            protected String doInBackground(Void... voids) {
                try {
                    URL url = new URL("https://api.tianapi.com/wxnew/?key=8d6e3228d25298f13af4fc40ce6c9679&num=10&page=1");
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setReadTimeout(5000);
                    connection.setConnectTimeout(5000);
                    int responseCode = connection.getResponseCode();
                    if (responseCode == 200){
                        InputStream inputStream = connection.getInputStream();
                        String json = streamToString(inputStream , "utf-8");

                        return json ;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return "";
            }

            @Override
            protected void onPostExecute(String s) {
                Gson gson=new Gson();
                DataDataBean dataDataBean = gson.fromJson(s, DataDataBean.class);
              list.addAll(dataDataBean.getNewslist());
                setAdapter();
                refresh_list_view.onRefreshComplete();
            }
        };
        asyncTask.execute();
    }

    private void setAdapter() {
        if (myAdapter == null) {
            myAdapter = new MyAdapter(MainActivity.this, list);
            refresh_list_view.setAdapter(myAdapter);
        }else{
            myAdapter.notifyDataSetChanged();
        }
    }

    private void getData() {
        AsyncTask<Void, Void, String> asyncTask = new AsyncTask<Void, Void, String>() {
            @Override
            protected String doInBackground(Void... voids) {
                try {
                    URL url = new URL("https://api.tianapi.com/wxnew/?key=8d6e3228d25298f13af4fc40ce6c9679&num=10&page="+page);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setReadTimeout(5000);
                    connection.setConnectTimeout(5000);
                    int responseCode = connection.getResponseCode();
                    if (responseCode == 200){
                        InputStream inputStream = connection.getInputStream();
                        String json = streamToString(inputStream , "utf-8");

                        return json ;
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return "";
            }
            @Override
            protected void onPostExecute(String s) {
                Gson gson = new Gson();
                DataDataBean dataDataBean = gson.fromJson(s, DataDataBean.class);
                list.addAll(dataDataBean.getNewslist());
                setAdapter();

            }
        };
        asyncTask.execute();



    }

    private String streamToString(InputStream inputStream, String charset) {
        try {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream,charset);

            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String s = null;
            StringBuilder builder = new StringBuilder();
            while ((s = bufferedReader.readLine()) != null){
                builder.append(s);
            }

            bufferedReader.close();
            return builder.toString();

        } catch (Exception e) {
            e.printStackTrace();
        }

        return  null;
    }
}