PullToRefresh

Posted 2020-07-28 牛皮

PullToRefreshListView的使用，实现下拉刷新，上拉加载更多。
首先是布局文件：

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

之后是代码

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.format.DateUtils;
import android.widget.ArrayAdapter;
import android.widget.ListView;

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

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    private PullToRefreshListView pListView;// PullToRefreshListView控件对象
    private ArrayAdapter adapter;
    private int counter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        pListView = (PullToRefreshListView) findViewById(R.id.plistview);
        counter=1;
        ArrayList<String> arrayList = new ArrayList<String>();
         // 初始化适配器
         adapter = new ArrayAdapter<String>(this, R.layout.item_layout, R.id.tv_item_name, arrayList);
         adapter.add("snail");
         adapter.add("_snail");
         adapter.add("__snail");
         adapter.add("___snail");
         // 绑定适配器
         pListView.setAdapter(adapter);
//PULL_FROM_END是只有上拉加载更多
//Mode.BOTH：同时支持上拉下拉
//Mode.PULL_FROM_START：只支持下拉更新 

pListView.setMode(PullToRefreshBase.Mode.PULL_FROM_END);

        // 设置刷新监听
        pListView.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener<ListView>() {
            @Override
            public void onRefresh(PullToRefreshBase<ListView> refreshView) {

                String str = DateUtils.formatDateTime(MainActivity.this, System.currentTimeMillis(), DateUtils.FORMAT_SHOW_TIME | DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_ABBREV_ALL);
                // 下拉刷新 业务代码
                if (refreshView.isShownHeader()) {
                    pListView.getLoadingLayoutProxy().setRefreshingLabel("正在刷新");
                    pListView.getLoadingLayoutProxy().setPullLabel("下拉刷新");
                    pListView.getLoadingLayoutProxy().setReleaseLabel("释放开始刷新");
                    refreshView.getLoadingLayoutProxy().setLastUpdatedLabel("最后更新时间:" + str);
                    new MyTask().execute();
                }
                // 上拉加载更多 业务代码
                if(refreshView.isShownFooter()) {
                    pListView.getLoadingLayoutProxy().setRefreshingLabel("正在加载");
                    pListView.getLoadingLayoutProxy().setPullLabel("上拉加载更多");
                    pListView.getLoadingLayoutProxy().setReleaseLabel("释放开始加载");
                    refreshView.getLoadingLayoutProxy().setLastUpdatedLabel("最后加载时间:" + str);
                    new MyTask().execute();
                }
            }
        });
    }
    private class MyTask extends AsyncTask<Void, Void, ArrayList<String>> {

                         @Override protected ArrayList<String> doInBackground(Void... params) {
                         try {
                                 Thread.sleep(2000);//睡眠2秒，延迟加载数据
                             } catch (InterruptedException e) {
                                 e.printStackTrace();
                             }
                         ArrayList<String> mArrayList = new ArrayList<String>();
                         for (int i = 0; i < 5; i++) {
                                 counter++;
                                 mArrayList.add("-----" + String.valueOf(counter) + "-------");
                             }
                         return mArrayList;
                     }

                         @Override
                 protected void onPostExecute(ArrayList<String> result) {
                         for (String string : result) {
                                 adapter.add(string);
                             }
                         pListView.onRefreshComplete();//数据加载到适配器完成后，刷新完成，
                         super.onPostExecute(result);
                     }

                     }
}

注：要想实现上拉加载更多需要在包“com.handmark.pulltorefresh.library”下的PullToRefreshBase这个类中加入两个新接口：

//判别头部是否展示出来，如果展示出来代表下拉使得头部展示。true为下拉
    public boolean isShownHeader() {
        return getHeaderLayout().isShown();
    }

    //判别低部是否展示出来，如果展示出来代表上拉使得低部展示。true为上拉
    public boolean isShownFooter() {
        return getFooterLayout().isShown();
    }