Question

我从我的php页面获取图像URL并使用JSON解析，我需要将图像插入列表视图，但我不知道我该怎么做。任何人都可以帮助我吗？我的代码在这里：

            // Getting JSON from URL
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            // getting JSON string from URL
            JSONObject json1 =  jParser.makeHttpRequest(url_all_products,"GET",params);

             Log.d("All Products: ", json1.toString());
                try {
                        products = json1.getJSONArray(TAG_PRODUCTS);

                        // looping through All Products
                        for (int i = 0; i < products.length(); i++) {
                            JSONObject c = products.getJSONObject(i);
                          String name = c.getString(TAG_NAME);
             String url = c.getString(TAG_URL);

                HashMap<String, String> map = new HashMap<String, String>();
              map.put(TAG_URL, url);
              map.put(TAG_NAME, name);
              productsList.add(map);
              ListAdapter adapter = new SimpleAdapter(
                     getActivity(), productsList,
                      R.layout.items, new String[] {
                              TAG_NAME},
                      new int[] { R.id.name });
              ListView list = (ListView) getView().findViewById(R.id.list);
              list.setAdapter(adapter);





                        }
            } catch (JSONException e) {
              e.printStackTrace();
            }

Answer 1

最好使用Lazyloading

您可以使用thest1/LazyList

或高级图像缓存Android-Universal-Image-Loader From here

Android-Universal-Image-Loader包含不同的示例，用于列出从url到列表视图的图像。

编辑后

您设置适配器的主要功能

在您的代码中设置并初始化 for循环中的列表视图，这是错误的，您需要使用自定义适配器使用延迟加载列出图像。下面的代码是您的代码后我编辑了部分内容。

 // Getting JSON from URL
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    // getting JSON string from URL
    JSONObject json1 =  jParser.makeHttpRequest(url_all_products,"GET",params);

     Log.d("All Products: ", json1.toString());
        try {
                products = json1.getJSONArray(TAG_PRODUCTS);

                // looping through All Products
                for (int i = 0; i < products.length(); i++) {
                    JSONObject c = products.getJSONObject(i);
                  String name = c.getString(TAG_NAME);
     String url = c.getString(TAG_URL);

        HashMap<String, String> map = new HashMap<String, String>();
      map.put(TAG_URL, url);
      map.put(TAG_NAME, name);
      productsList.add(map);





                }

//DON'T SET ADAPTER IN A LOOP
                MyListViewAdaptor adapter = new MyListViewAdaptor(
                        getActivity(), productsList,
                         );
                 ListView list = (ListView) getView().findViewById(R.id.list);
                 list.setAdapter(adapter);

    } catch (JSONException e) {
      e.printStackTrace();
    }

编写一个custum适配器，将您的图像显示到SimpleAdapter以外的列表视图，并使用adpator中延迟加载中使用的函数并显示图像。让我们创建一个适配器MyListViewAdaptor。示例如下所示

<强> MyListViewAdaptor.java

public class MyListViewAdaptor extends BaseAdapter {

// Declaring Variables

private Activity activity;
private ArrayList<HashMap<String, String>> myarray;
private static LayoutInflater inflater = null;
public ImageLoader imageLoader;
   // PLAESE READ ImageLoader IS A CLASS FROM LIB thest1/LazyList LAZYLOADING


public MyListViewAdaptor(Activity a, ArrayList<HashMap<String, String>> myarray) {

    activity = a;

    this.myarray = myarray;

    inflater = (LayoutInflater) activity
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    imageLoader = new ImageLoader(activity);


}

public int getCount() {

    return myarray.size();

}

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)

        // Get the view from mainpage_row.xml

        vi = inflater.inflate(R.layout.yourlistviewrowname, null);


    ImageView userImage = (ImageView) vi
            .findViewById(R.id.youtimageviewname);
TextView textName = (TextView) vi.findViewById(R.id.yourtextviewname);

    HashMap<String, String> datamap = new HashMap<String, String>();
    datamap = myarray.get(position);

    textName.setText(datamap.get("yourTextKeyHere"));




    imageLoader.DisplayImage(datamap.get("yourImageKeyHere"), userImage);


    return vi;
}
}

不要忘记添加权限

  <uses-permission android:name="android.permission.INTERNET" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

希望这会对你有所帮助

Answer 2

这是适配器类

class ItemAdapter extends BaseAdapter {

        private ImageLoadingListener animateFirstListener = new AnimateFirstDisplayListener();

        private class ViewHolder {
            public TextView text;
            public ImageView image;
        }

        @Override
        public int getCount() {
            return imageUrls.length;
        }

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

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

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            View view = convertView;
            final ViewHolder holder;
            if (convertView == null) {
                view = getLayoutInflater().inflate(R.layout.item_list_image, parent, false);
                holder = new ViewHolder();
                holder.text = (TextView) view.findViewById(R.id.text);
                holder.image = (ImageView) view.findViewById(R.id.image);
                view.setTag(holder);
            } else {
                holder = (ViewHolder) view.getTag();
            }

            holder.text.setText("Item " + (position + 1));

            imageLoader.displayImage(imageUrls[position], holder.image, options, animateFirstListener);

            return view;
        }
    }

这是主要的活动

public class ImageListActivity extends AbsListViewBaseActivity {

    DisplayImageOptions options;

    String[] imageUrls;

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

        Bundle bundle = getIntent().getExtras();
        imageUrls = bundle.getStringArray(Extra.IMAGES);

        options = new DisplayImageOptions.Builder()
            .showImageOnLoading(R.drawable.ic_stub)
            .showImageForEmptyUri(R.drawable.ic_empty)
            .showImageOnFail(R.drawable.ic_error)
            .cacheInMemory(true)
            .cacheOnDisc(true)
            .considerExifParams(true)
            .displayer(new RoundedBitmapDisplayer(20))
            .build();

        listView = (ListView) findViewById(android.R.id.list);
        ((ListView) listView).setAdapter(new ItemAdapter());
        listView.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                startImagePagerActivity(position);
            }
        });
    }
}

**它是来自通用图像加载器的官方网站的示例

列表视图中URL的图像

2 个答案: