android - ListView 部分加载网络 json 数据

Question

我想在ListView.

上网查了一下，还是不知道怎么加载json部分网络数据ListView。

现在我发布我的代码并请求其他人帮助我。非常感谢！

public class MainActivity extends ListActivity{


    private ListView listView;
    File cache = null;
    private String path ="Here is the json file on the server address";

        Handler handler = new Handler(){
            public void handleMessage(Message msg) {
                 listView.setAdapter(new VideoFileAdapter(MainActivity.this, (List<VideoFile>)msg.obj, 
                         R.layout.listview_item, cache));
            }

视频文件服务.java

        };
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            this.requestWindowFeature(Window.FEATURE_NO_TITLE);
            setContentView(R.layout.activity_main);
            listView = getListView();


            cache = new File(Environment.getExternalStorageDirectory(), "cache");
            if(!cache.exists()) cache.mkdirs();
            new Thread(new Runnable() {            
                public void run() {
                    try {
                        List<VideoFile> data = VideoFileService.getJSONVideoFile(path);
                        handler.sendMessage(handler.obtainMessage(22, data));
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();       
        }

        protected void onDestroy() {
            super.onDestroy();
        }

    }

视频文件适配器.java

public class VideoFileAdapter extends BaseAdapter {
    public List<VideoFile> data;
    public int listviewItem;
    private File cache;
    LayoutInflater layoutInflater;

    public VideoFileAdapter(Context context, List<VideoFile> data, int listviewItem, File cache) {
        this.data = data;
        this.listviewItem = listviewItem;
        this.cache = cache;
        layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }
    public int getCount() {
        return data.size();    
    }
    public Object getItem(int position) {
        return data.get(position);
    }

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

    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView = null;
        TextView textView = null;

        if(convertView == null){
            convertView = layoutInflater.inflate(listviewItem, null);
            imageView = (ImageView) convertView.findViewById(R.id.image);
            textView = (TextView) convertView.findViewById(R.id.textView);
            convertView.setTag(new DataWrapper(imageView, textView));
        }else{
            DataWrapper dataWrapper = (DataWrapper) convertView.getTag();
            imageView = dataWrapper.imageView;
            textView = dataWrapper.textView;    
        }
        VideoFile videoFile = data.get(position);
        textView.setText(videoFile.name);
        asyncImageLoad(imageView, videoFile.image);
        return convertView;
    }

    private void asyncImageLoad(ImageView imageView, String path) {
        AsyncImageTask asyncImageTask = new AsyncImageTask(imageView);
        asyncImageTask.execute(path);
    }

    private final class AsyncImageTask extends AsyncTask<String, Integer, Uri>{
        private ImageView imageView;
        public AsyncImageTask(ImageView imageView) {
            this.imageView = imageView;
        }
        protected Uri doInBackground(String... params) {
            try {
                return VideoFileService.getImage(params[0], cache);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
        protected void onPostExecute(Uri result) {
            if(result!=null && imageView!= null)
                imageView.setImageURI(result);
        }
    }

    private final class DataWrapper{
        public ImageView imageView;
        public TextView textView;
        public DataWrapper(ImageView imageView, TextView textView) {
            this.imageView = imageView;
            this.textView = textView;
        }
    }

    public void addItem(VideoFile item) {
        data.add(item);

    }
}