Android中ListView上拉刷新的功能实现（总结）

效果图如下：

1、自定义一个LoadMoreListView继承自ListVIew，同时提供加载接口

（原理就是通过对FooterView的控制实现上划加载的效果）

代码如下：

package com.crazyboy.glideshowimagedemo;

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ListView;

public class LoadMoreListView extends ListView {

    private Context mContext;
    private View mLoadMoreFooter;
    private OnLoadMoreListener mLoadMoreListener;
    private boolean mAddedFooter;
    private boolean mLoadMore;


    public interface OnLoadMoreListener extends OnScrollListener {
        // 加载更多数据
        void onLoadMoreData();
    }

    public LoadMoreListView(Context context) {
        super(context);
        mContext = context;
        init();
    }

    public LoadMoreListView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        init();
    }

    public LoadMoreListView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        mContext = context;
        init();
    }

    private void init() {
        mLoadMoreFooter = LayoutInflater.from(mContext).inflate(R.layout.load_more_view, null);

        this.setOnScrollListener(new OnScrollListener() {
            @Override
            public void onScrollStateChanged(AbsListView view, int scrollState) {
                if (mLoadMoreListener != null) {
                    mLoadMoreListener.onScrollStateChanged(view, scrollState);
                }
            }

            @Override
            public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                if (mLoadMoreListener != null) {
                    mLoadMoreListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
                    // 滑动到底部显示LoadingMore
                    if (firstVisibleItem + visibleItemCount == totalItemCount && mLoadMore) {
                        showLoadMoreView();
                        // 加载耗时操作
                        post(new Runnable() {
                            @Override
                            public void run() {
                                mLoadMoreListener.onLoadMoreData();
                                mLoadMore = false;
                            }
                        });
                    }
                }
            }
        });
    }

    // 加载数据完成
    public void loadMoreComplete() {
        deferNotifyDataSetChanged();
        setLoadMore(false);
    }

    public void setLoadMore(boolean loadMore) {
        mLoadMore = loadMore;
        if (!loadMore) {
            removeFooterView(mLoadMoreFooter);
        }
    }


    private void showLoadMoreView() {
        if (!mAddedFooter) {
            addFooterView(mLoadMoreFooter);
            mAddedFooter = true;
        }
    }

    public void setLoadMoreListener(OnLoadMoreListener loadMoreListener) {
        this.mLoadMoreListener = loadMoreListener;
    }
}

2、在相应的Activity中调用并实现加载接口。代码如下：

package com.crazyboy.glideshowimagedemo;

import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.AbsListView;

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

public class MainActivity extends AppCompatActivity {

    private Context mContext;
    private List<Tb_NewsInfo> tbNewsInfoList;
    private Tb_NewsInfo tb_newsInfo;
    private NewsListAdapter newsListAdapter;
    private LoadMoreListView LMLVNewsList;
    private String[] urlStrs = new String[]{ "http://pic14.photophoto.cn/20100127/0036036848818577_b.jpg"
            , "http://img.pconline.com.cn/images/upload/upc/tx/wallpaper/1209/11/c0/13783009_1347330674323.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg", "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg", "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg", "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg", "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg", "http://pic9.photophoto.cn/20081105/0034034891195212_b.jpg"
            , "http://nba.sports.qq.com/media/img/players/head/260x190/201935.png"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //判断android版本号，弹出申请权限
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            showConfirmAppPermissions();
        }

        bindBaseInfoInit();
        bindView();
        setViewBaseState();
    }

    private void bindBaseInfoInit() {
        mContext = this;
        tbNewsInfoList = new ArrayList<>();
    }

    private void bindView() {
        LMLVNewsList = findViewById(R.id.main_LMLVNewsList);
    }

    private void setViewBaseState() {
        for (int i = 0; i< urlStrs.length; i++) {
            String title = "这是一条新闻的标题内容";
            tb_newsInfo = new Tb_NewsInfo(urlStrs[i], title);
            tbNewsInfoList.add(tb_newsInfo);
        }
        newsListAdapter = new NewsListAdapter(mContext, tbNewsInfoList);
        LMLVNewsList.setAdapter(newsListAdapter);
        LMLVNewsList.setLoadMore(true);
        LMLVNewsList.setLoadMoreListener(new LoadMoreListView.OnLoadMoreListener() {
            @Override
            public void onLoadMoreData() {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            Thread.sleep(3000);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        for (int i = 0; i< urlStrs.length; i++) {
                            String title = "这是一条新闻的标题内容";
                            String url1 = "http://pic14.photophoto.cn/20100127/0036036848818577_b.jpg";
                            tb_newsInfo = new Tb_NewsInfo(url1, title);
                            tbNewsInfoList.add(tb_newsInfo);
                        }
                        LMLVNewsList.post(new Runnable() {
                            @Override
                            public void run() {
                                LMLVNewsList.loadMoreComplete();
                            }
                        });
                    }
                }).start();
            }

            @Override
            public void onScrollStateChanged(AbsListView absListView, int i) {

            }

            @Override
            public void onScroll(AbsListView absListView, int i, int i1, int i2) {

            }
        });
    }

    // 7.0动态申请权限
    public void showConfirmAppPermissions() {
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE) !=
                PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            } else {
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,
                                Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.CAMERA}, 1);
            }
        }
    }
}