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  • 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

    2015-01-06_152406_副本2015-01-06_152509_副本

    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。

    1

    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。

    3

    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。

    4-1_副本

    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。

    5-1_副本

    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。

    6-1_副本
    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
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  • 原文地址：https://www.cnblogs.com/liuning8023/p/4206215.html
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