Android 演示 Android ListView 和 github XListView（1-3）

本文内容

• 环境
• 项目结构
• 演示 1：ListView
• 演示 2：简单 XListView
• 演示 3：音乐列表 XListView
• 演示 4：另一个音乐列表 XListView

本文四个演示，循序渐进。

• 演示 1 只是普通的 Android ListView 控件；
• 演示 2 是 GitHub 上的 XListView 控件，具备“下拉更新”和“上拉加载”功能，使用是它自己的示例；
• 演示 3 是将音乐列表的数据应用到 XListView 控件，但只访问一次网络，“下拉更新”和“上拉加载”时循环利用数据；
• 演示 4 与演示 3 基本一致，唯一的区别是每次“下拉更新”和“上拉加载”时都访问网络，以便跟实际情况更相近。

下载 github XListView

下载 Demo

更多 Demo

环境

---

• Windows 2008 R2 64 位
• Eclipse ADT V22.6.2，Android 4.4.2（API 19）
• SAMSUNG GT-8618，Android OS 4.1.2

项目结构

---

图 1 项目结构（左：Java 包；右：布局文件）

• com.example.listviewdemo.adapter 包是 android ListView 和 XListView 控件的adaper；
• com.example.listviewdemo.config 包只有一个类 Urls，类中只有一个关于音乐列表数据网络地址的静态变量；
• com.example.listviewdemo.dao 包是业务层，根据网络地址获得音乐列表数据；
• com.example.listviewdemo.ui 包是演示中使用的 Activity；
• com.example.listviewdemo.utils 包是工具类；
• com.example.listviewdemo.widget 包是 github 的 XListView 控件。

图 2 主程序界面

 

演示 1：ListView

---

利用 AsyncTask 通过网络获得音乐列表数据，数据是 JSON 数组，ListView 控件相应的 adpter 规定了列表中每项是如何显示的。

图 3 演示 1

package com.example.listviewdemo.ui;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.example.listviewdemo.R;
import com.example.listviewdemo.adapter.SimpleListAdapter;
import com.example.listviewdemo.dao.MusicDao;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;

public class SimpleListActivity extends Activity {

    private ListView list;
    private SimpleListAdapter adapter;
    private MusicDao music;
    private JSONArray jsonArray;

    /* Button btn; */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_simplelist);

        initClass();

        InitListView();

        new MyTask().execute(music);
    }

    private void initClass() {
        music = new MusicDao();
    }

    private void InitListView() {
        list = (ListView) findViewById(R.id.myList_a);
    }

    public class MyTask extends AsyncTask<MusicDao, String, String> {

        private boolean mUseCache;

        public MyTask() {
            mUseCache = true;
        }

        public MyTask(boolean useCache) {
            mUseCache = useCache;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected String doInBackground(MusicDao... params) {
            MusicDao dao = params[0];
            String result = dao.getData();
            return result;
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            if (!result.isEmpty()) {
                try {
                    jsonArray = new JSONArray(result);
                    adapter = new SimpleListAdapter(SimpleListActivity.this,
                            jsonArray);
                    list.setAdapter(adapter);
                    list.setOnItemClickListener(new OnItemClickListener() {

                        @Override
                        public void onItemClick(AdapterView<?> parent,
                                View view, int position, long id) {
                            JSONObject jObject;
                            try {
                                jObject = (JSONObject) jsonArray.get(position);
                                Toast.makeText(getApplicationContext(),
                                        jObject.getString("artist"),
                                        Toast.LENGTH_SHORT).show();
                            } catch (JSONException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                        }
                    });
                    list.setOnItemSelectedListener(new OnItemSelectedListener() {

                        @Override
                        public void onItemSelected(AdapterView<?> parent,
                                View view, int position, long id) {
                            JSONObject jObject;
                            try {
                                jObject = (JSONObject) jsonArray.get(position);
                                Toast.makeText(getApplicationContext(),
                                        jObject.getString("artist"),
                                        Toast.LENGTH_SHORT).show();
                            } catch (JSONException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                        }

                        @Override
                        public void onNothingSelected(AdapterView<?> parent) {
                        }
                    });
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

 

演示 2：简单 XListView

---

演示了 github 上的 XListView 控件。示例是该控件提供的。XListView 控件提供“下拉更新”和“上拉加载”功能，并可对“下拉”和“上拉”操作启用或禁用，毕竟不是所有场景都同时需要这个两个操作。

图 4 演示 2

package com.example.listviewdemo.ui;

import java.util.ArrayList;

import org.json.JSONException;
import org.json.JSONObject;

import com.example.listviewdemo.R;
import com.example.listviewdemo.widget.XListView;
import com.example.listviewdemo.widget.XListView.IXListViewListener;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;

public class SimpleXListActivity extends Activity implements IXListViewListener {
    private XListView mListView;
    private ArrayAdapter<String> mAdapter;
    private ArrayList<String> items = new ArrayList<String>();
    private Handler mHandler;
    private int start = 0;
    private static int refreshCnt = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_simplexlist);

        geneItems();

        initClass();

        initControl();

        initXList();

    }

    private void geneItems() {
        for (int i = 0; i != 20; ++i) {
            items.add("refresh cnt " + (++start));
        }
    }

    private void initClass() {
        mHandler = new Handler();
    }

    private void initControl() {
        mListView = (XListView) findViewById(R.id.xListView_a);
        mAdapter = new ArrayAdapter<String>(this, R.layout.xlist_simpleitem,
                items);
    }

    private void initXList() {
        mListView.setPullLoadEnable(true);
        mListView.setPullRefreshEnable(true);
        mListView.setAdapter(mAdapter);
        mListView.setXListViewListener(this);
        mListView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {

                Toast.makeText(getApplicationContext(), items.get(position),
                        Toast.LENGTH_SHORT).show();
            }
        });
        mListView.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                Toast.makeText(getApplicationContext(), items.get(position),
                        Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
    }

    private void onLoad() {
        mListView.stopRefresh();
        mListView.stopLoadMore();
        mListView.setRefreshTime("刚刚");
    }

    // Refresh
    @Override
    public void onRefresh() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                start = ++refreshCnt;
                items.clear();
                geneItems();
                // mAdapter.notifyDataSetChanged();
                mAdapter = new ArrayAdapter<String>(SimpleXListActivity.this,
                        R.layout.xlist_simpleitem, items);
                mListView.setAdapter(mAdapter);
                onLoad();
            }
        }, 2000);
    }

    // LoadMore
    @Override
    public void onLoadMore() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                geneItems();
                mAdapter.notifyDataSetChanged();
                onLoad();
            }
        }, 2000);
    }
}

 

演示 3：音乐列表 XListView

---

该演示只是在演示 2 的基础上，改变列表数据，简单起见，只访问一次网络，缓存在成员变量，“下拉更新”和“上拉加载”时循环利用。

图 5 演示 3

package com.example.listviewdemo.ui;

import org.json.JSONArray;
import org.json.JSONException;

import com.example.listviewdemo.R;
import com.example.listviewdemo.adapter.SimpleListAdapter;
import com.example.listviewdemo.dao.MusicDao;
import com.example.listviewdemo.widget.XListView;
import com.example.listviewdemo.widget.XListView.IXListViewListener;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;

public class XListActivity extends Activity implements IXListViewListener {

    private XListView mListView;
    private SimpleListAdapter mAdapter;
    private JSONArray jsonArray;
    private JSONArray items;
    private MusicDao music;

    private Handler mHandler;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_xlist);

        initClass();

        initControl();

        initXList();

        new MyTask().execute(music);
    }

    private void initClass() {
        music = new MusicDao();
        mHandler = new Handler();
        items = new JSONArray();
    }

    private void initControl() {
        mListView = (XListView) findViewById(R.id.xListView_b);
    }

    private void initXList() {
        mListView.setPullLoadEnable(true);
        mListView.setPullRefreshEnable(true);
        mListView.setXListViewListener(this);
        mListView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                try {
                    Toast.makeText(getApplicationContext(),
                            items.get(position).toString(), Toast.LENGTH_SHORT)
                            .show();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        });
        mListView.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                try {
                    Toast.makeText(getApplicationContext(),
                            items.get(position).toString(), Toast.LENGTH_SHORT)
                            .show();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
    }

    private void onLoad() {
        mListView.stopRefresh();
        mListView.stopLoadMore();
        mListView.setRefreshTime("刚刚");
    }

    // Refresh
    @Override
    public void onRefresh() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                for (int i = 9; i >= 0; i--) {
                    try {
                        items.put(jsonArray.get(i));
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                // mAdapter.notifyDataSetChanged();
                mAdapter = new SimpleListAdapter(XListActivity.this, items);
                mListView.setAdapter(mAdapter);
                onLoad();
            }
        }, 2000);
    }

    // LoadMore
    @Override
    public void onLoadMore() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                try {
                    for (int i = 0; i < 10; i++) {
                        items.put(jsonArray.get(i));
                    }
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                mAdapter.notifyDataSetChanged();
                onLoad();
            }
        }, 2000);
    }

    public class MyTask extends AsyncTask<MusicDao, String, String> {

        private boolean mUseCache;

        public MyTask() {
            mUseCache = true;
        }

        public MyTask(boolean useCache) {
            mUseCache = useCache;
        }

        /* 鎵ц鍓嶏紝鐩稿叧椤甸潰澶勭悊 */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        /* 鎵ц涓� */
        @Override
        protected String doInBackground(MusicDao... params) {
            MusicDao dao = params[0];
            String result = dao.getData();
            return result;
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            if (!result.isEmpty()) {
                try {
                    jsonArray = new JSONArray(result);
                    for (int i = 0; i < jsonArray.length(); i++) {
                        items.put(jsonArray.get(i));
                    }

                    mAdapter = new SimpleListAdapter(XListActivity.this, items);
                    mListView.setAdapter(mAdapter);

                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

 

演示 4：另一个音乐列表 XListView

---

该演示是在演示 3 的基础上，“下拉更新”和“上拉加载”时都访问网络，重复利用数据。

但是，这个演示，在每次“下拉更新”和“上拉加载”时，都会调用 AsyncTask，不知道是否合适，不过 android 貌似不推荐这么做。

package com.example.listviewdemo.ui;

import org.json.JSONArray;
import org.json.JSONException;

import com.example.listviewdemo.R;
import com.example.listviewdemo.adapter.SimpleListAdapter;
import com.example.listviewdemo.dao.MusicDao;
import com.example.listviewdemo.widget.XListView;
import com.example.listviewdemo.widget.XListView.IXListViewListener;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;

public class XListAnotherActivity extends Activity implements
        IXListViewListener {

    private XListView mListView;
    private SimpleListAdapter mAdapter;
    private JSONArray jsonArray;
    private JSONArray items;
    private MusicDao music;

    private Handler mHandler;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_xlistanother);

        initClass();

        initControl();

        initXList();

        new MyTask().execute(music);
    }

    private void initClass() {
        music = new MusicDao();
        mHandler = new Handler();
        items = new JSONArray();
    }

    private void initControl() {
        mListView = (XListView) findViewById(R.id.xListView_c);
        mAdapter = new SimpleListAdapter(XListAnotherActivity.this, items);
    }

    private void initXList() {
        mListView.setPullLoadEnable(true);
        mListView.setPullRefreshEnable(false);
        mListView.setXListViewListener(this);
        mListView.setAdapter(mAdapter);
        mListView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                try {
                    Toast.makeText(getApplicationContext(),
                            items.get(position).toString(), Toast.LENGTH_SHORT)
                            .show();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        });
        mListView.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                try {
                    Toast.makeText(getApplicationContext(),
                            items.get(position).toString(), Toast.LENGTH_SHORT)
                            .show();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
    }

    private void onLoad() {
        mListView.stopRefresh();
        mListView.stopLoadMore();
        mListView.setRefreshTime("刚刚");
    }

    // Refresh
    @Override
    public void onRefresh() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                for (int i = 9; i >= 0; i--) {
                    try {
                        items.put(jsonArray.get(i));
                    } catch (JSONException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }

                new MyTask().execute(music);
                onLoad();
            }
        }, 2000);
    }

    // LoadMore
    @Override
    public void onLoadMore() {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                try {
                    for (int i = 0; i < 10; i++) {
                        items.put(jsonArray.get(i));
                    }
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                // mAdapter.notifyDataSetChanged();
                new MyTask().execute(music);
                onLoad();
            }
        }, 2000);
    }

    public class MyTask extends AsyncTask<MusicDao, String, String> {

        private boolean mUseCache;

        public MyTask() {
            mUseCache = true;
        }

        public MyTask(boolean useCache) {
            mUseCache = useCache;
        }


        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }


        @Override
        protected String doInBackground(MusicDao... params) {
            MusicDao dao = params[0];
            String result = dao.getData();
            return result;
        }

        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);
            if (!result.isEmpty()) {
                try {
                    jsonArray = new JSONArray(result);
                    jsonArray = new JSONArray(result);
                    for (int i = 0; i < jsonArray.length(); i++) {
                        items.put(jsonArray.get(i));
                    }
                    mAdapter.notifyDataSetChanged();

                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

 

最后，这四个演示都需要的 Adapter，如下所示：

package com.example.listviewdemo.adapter;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.example.listviewdemo.R;
import com.example.listviewdemo.utils.ImageLoader;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class SimpleListAdapter extends BaseAdapter {

    private Activity activity;
    private JSONArray data;
    private static LayoutInflater inflater = null;
    public ImageLoader imageLoader;

    public SimpleListAdapter(Activity a, JSONArray jsonArr) {
        activity = a;
        data = jsonArr;
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader = new ImageLoader(activity.getApplicationContext());

    }

    public int getCount() {
        return data == null ? 0 : data.length();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View vi = convertView;
        if (convertView == null)
            vi = inflater.inflate(R.layout.list_row, null);

        JSONObject song = null;

        ImageView image = (ImageView) vi.findViewById(R.id.imagethumb);
        TextView tvartist = (TextView) vi.findViewById(R.id.artist);
        TextView tvtitle = (TextView) vi.findViewById(R.id.title);
        TextView tvduration = (TextView) vi.findViewById(R.id.duration);

        try {
            song = data.getJSONObject(position);
            imageLoader.DisplayImage(song.getString("thumb_url"), image);
            tvartist.setText(song.getString("artist"));
            tvtitle.setText(song.getString("title"));
            tvduration.setText(song.getString("duration"));
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return vi;
    }
}

 

Android github XListView 分析（2-3）

Android 演示 Android ListView 和 github XListView（3-3）

 

下载 Demo