Android PullToRefresh——ListView使用详解

    前段时间，在使用ListView的过程中突然发现PullToRefresh的使用方法，用于上拉下拉刷新使用，觉得该方法很好使用，特此分享，供大家参考。

    由于PullToRefresh方法是开源的第三方插件使用，所以使用步骤如下：

1、在GitHub上面下载源码以及需使用的包，地址为https://github.com/chrisbanes/Android-PullToRefresh，将library文件夹引用至自己的工作项目。（再此不做详细的导入说明）

2、导入完成之后，就可以开始编写自己的xml文件，具体代码如下。

注意：为了使用PullToRefresh一些属性，需要引命名空间，因此

xmlns:ptr = "http://schemas.android.com/apk/res-auto"
ptr:ptrMode="both"

该两行代码不能省略。

3、编写java文件，具体代码如下。

package pulltorefresh.pulltorefresh;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshBase.OnRefreshListener2;
import com.handmark.pulltorefresh.library.PullToRefreshListView;

import java.util.Arrays;
import java.util.LinkedList;

/**
 * PullToRefresh
 * write by jimmy.li
 * 2016/4/9  22:58
 */

public class MainActivity extends Activity {

    private LinkedList mListItems;
    private PullToRefreshListView mPullRefreshListView;
    private ArrayAdapter mAdapter;

    private int mDowmAddNum = 1;
    private int mUpAddNum = 1;

    //每次刷新增加5个listItem
    private int mAddFalg = 5;

    //数据源
    private String[] mStrings = {"Jimmy1", "Jimmy2", "Jimmy3", "Jimmy4", "Jimmy5",
            "Jimmy6", "Jimmy7", "Jimmy8", "Jimmy9", "Jimmy10", "Jimmy11", "Jimmy12",
            "Jimmy13", "Jimmy14", "Jimmy15", "Jimmy16", "Jimmy17", "Jimmy18", "Jimmy19",
            "Jimmy20", "Jimmy21", "Jimmy22", "Jimmy23", "Jimmy24", "Jimmy25", "Jimmy26"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        initUI();
        initData();

    }

    private void initData() {
        /**
         * 实现 接口  OnRefreshListener2  以便与监听  滚动条到顶部和到底部
         */
        mPullRefreshListView.setOnRefreshListener(new OnRefreshListener2() {
            //onPullDownToRefresh
            @Override
            public void onPullDownToRefresh(PullToRefreshBase refreshView) {
                Toast.makeText(MainActivity.this, "onPullDownToRefresh", Toast.LENGTH_SHORT).show();
                for (int i = 1; i <= mAddFalg; i++) {
                    mListItems.addFirst("Added Later refresh..." + mDowmAddNum);
                    mDowmAddNum++;
                }
                 new GetDataTask().execute();
            }


            //onPullUpToRefresh
            @Override
            public void onPullUpToRefresh(PullToRefreshBase refreshView) {
                Toast.makeText(MainActivity.this, "onPullUpToRefresh", Toast.LENGTH_SHORT).show();
                for (int i = 1; i <= mAddFalg; i++) {
                    mListItems.addLast("Added after refresh..." + mUpAddNum);
                    mUpAddNum++;
                }

                 new GetDataTask().execute();
            }
        });


        //获取控件并注册
        ListView actualListView = mPullRefreshListView.getRefreshableView();

        registerForContextMenu(actualListView);

        mListItems = new LinkedList();
        mListItems.addAll(Arrays.asList(mStrings));

        //设置适配器
        mAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, mListItems);
        actualListView.setAdapter(mAdapter);
    }

    private void initUI() {
        mPullRefreshListView = (PullToRefreshListView) findViewById(R.id.pull_refresh_list);
    }

    //模拟网络加载数据的   异步请求类
    //
    private class GetDataTask extends AsyncTask {

        //子线程请求数据
        @Override
        protected String[] doInBackground(Void... params) {
            // Simulates a background job.
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
            }
            return mStrings;
        }

        //主线程更新UI
        @Override
        protected void onPostExecute(String[] result) {
            mAdapter.notifyDataSetChanged();

            // Call onRefreshComplete when the list has been refreshed.
            mPullRefreshListView.onRefreshComplete();
            super.onPostExecute(result);
        }
    }
}

4、主要代码讲解。

private void initData() {
        /**
         * 实现 接口  OnRefreshListener2  以便与监听  滚动条到顶部和到底部
         */
        mPullRefreshListView.setOnRefreshListener(new OnRefreshListener2() {
            //onPullDownToRefresh
            @Override
            public void onPullDownToRefresh(PullToRefreshBase refreshView) {
                Toast.makeText(MainActivity.this, "onPullDownToRefresh", Toast.LENGTH_SHORT).show();
                for (int i = 1; i <= mAddFalg; i++) {
                    mListItems.addFirst("Added Later refresh..." + mDowmAddNum);
                    mDowmAddNum++;
                }
                 new GetDataTask().execute();
            }


            //onPullUpToRefresh
            @Override
            public void onPullUpToRefresh(PullToRefreshBase refreshView) {
                Toast.makeText(MainActivity.this, "onPullUpToRefresh", Toast.LENGTH_SHORT).show();
                for (int i = 1; i <= mAddFalg; i++) {
                    mListItems.addLast("Added after refresh..." + mUpAddNum);
                    mUpAddNum++;
                }

                 new GetDataTask().execute();
            }
        });

上面主要是利用initData()函数将PullToRefresh上拉下拉刷新的主要代码封装起来，分别对应其下拉和上拉事件监听器。

 //获取控件并注册
        ListView actualListView = mPullRefreshListView.getRefreshableView();

        registerForContextMenu(actualListView);

        mListItems = new LinkedList();
        mListItems.addAll(Arrays.asList(mStrings));

        //设置适配器
        mAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, mListItems);
        actualListView.setAdapter(mAdapter);

上面代码主要是获取ListView空间并实行注册，并设置适配器以显示ListView。

Good luck!

Write by Jimmy.li