Question

我正在开发Android应用程序，我希望在水平列表视图中显示从Web服务检索的json格式文本和图像。我将json格式化数据存储到ArrayList

Answer 1

首先是如何显示水平ListView。我建议你使用RecyclerView来实现更顺畅的listView显示。那么如何在Horizontal中显示recyclerView？这是我一步一步的教程。

首先，在xml文件中应该是这样的：

  <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentBottom="true"
        android:scrollbars="vertical" />

其次，在活动中onCreate应该是这样的：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    recyclerViewItem = (RecyclerView) findViewById(R.id.recyclerView);
    LinearLayoutManager itemslayoutManager = new LinearLayoutManager(getApplicationContext());
    itemslayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
    recyclerViewItem.setLayoutManager(itemslayoutManager);
    SampleAdapter sampleAdapter = new SampleAdapter(List<SampleData>);
    recyclerViewItem.setAdapter(sampleAdapter);
    return true;
    }

要解析JSON，您应该使用名为Retrofit而不是AsyncTask的库试试这个： Retrofit

Answer 2

activity_main.xml

  <android.support.v4.view.ViewPager
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:numColumns="auto_fit"
    android:horizontalSpacing="4dp"
    android:stretchMode="columnWidth"
    android:id="@+id/gallery_child_list"
    android:background="#E4E4E4"
    android:verticalSpacing="4dp" />

Mainactivity

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Get the view from activity_main.xml
    setContentView(R.layout.activity_main);
    // Execute DownloadJSON AsyncTask
    new DownloadJSON().execute();
}

// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Create a progressdialog
        mProgressDialog = new ProgressDialog(MainActivity.this);
        // Set progressdialog message
        mProgressDialog.setMessage("Loading...");
        mProgressDialog.setIndeterminate(false);
        // Show progressdialog
        mProgressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        // Create an array
        arraylist = new ArrayList<HashMap<String, String>>();
        // Retrieve JSON Objects from the given URL address
        try {
            HttpClient client = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("YOUR_URL");
            HttpResponse response = client.execute(httppost);
            HttpEntity resEntity = response.getEntity();
            String json = EntityUtils.toString(resEntity);
            JSONObject jObject = new JSONObject(json);
            // Locate the array name in JSON
                HashMap<String, String> map = new HashMap<String, String>();
            JSONObject jsonobject = jObject.optJSONObject("online");
            for (int i = 0; i < jObject.length(); i++) {
                    map.put("date", jsonobject.getString("men"));
                    map.put("flag", jsonobject.getString("kids"));
                    map.put("flag", jsonobject.getString("women"));
                    // Set the JSON Objects into the array
                    arraylist.add(map);
                }
                } catch (Exception e1) {
                e1.printStackTrace();
            }
        return null;
    }
        @Override
    protected void onPostExecute(Void args) {
        viewPager = (ViewPager) findViewById(R.id.pager);
        adapter = new ViewPagerAdapter(MainActivity.this, arraylist);
        viewPager.setAdapter(adapter);
        // Close the progressdialog
        mProgressDialog.dismiss();
        adapter.notifyDataSetChanged();

    }
}

viewpageradapter

public class ViewPagerAdapter extends PagerAdapter {
// Declare Variables
Context context;
LayoutInflater inflater;
ArrayList<HashMap<String, String>> data;
ImageLoader imageLoader;
HashMap<String, String> resultp = new HashMap<String, String>();

public ViewPagerAdapter(Context context, ArrayList<HashMap<String, String>> arraylist) {
    this.context = context;
    data = arraylist;
    imageLoader = new ImageLoader(context);
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return view == ((RelativeLayout) object);
}

@Override
public int getCount() {
    return data.size();
}

        @Override
public Object instantiateItem(ViewGroup container, int position) {

    // Declare Variables
    ImageView imgflag;

    inflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View itemView = inflater.inflate(R.layout.viewpager_item, container,false);

    // Locate the ImageView in viewpager_item.xml
    imgflag = (ImageView) itemView.findViewById(R.id.flag);
            // Capture position
            resultp = data.get(position);
            // Capture position and set results to the ImageView
            // Passes flag images URL into ImageLoader.class
            imageLoader.DisplayImage(resultp.get(MainActivity.FLAG), imgflag);
            // Add viewpager_item.xml to ViewPager
            ((ViewPager) container).addView(itemView);

    return itemView;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // Remove viewpager_item.xml from ViewPager
    ((ViewPager) container).removeView((RelativeLayout) object);

}
}

如何在水平列表视图中显示从Web服务检索的Json文本和图像？

2 个答案: