将URL从URL添加到ListView中

Question

我正在使用contacts project from AndroidHive的修改版本。

它基本上只是从Joomla网站拉出n篇文章和他们的联系人。我使用Image Plugin从url获取图像。我可以在文章详细信息活动视图中成功使用它，但我不知道如何将它添加到MainAcitivity文件上的每个列表项。我对Android开发很陌生，请原谅混淆。

的脚本来添加图像：

ImageView thumb = (ImageView) findViewById(R.id.thumb); 
UrlImageViewHelper.setUrlDrawable(thumb, "https://www.site.co.za/test.png"); 

和产生的ListView我MainActivity：

public class MainActivity extends ListActivity { 

    private ProgressDialog pDialog; 

    // URL to get articles JSON 
    private static String url = "http://192.168.12.21/sebastian/broadcast/index.php/blog?format=json"; 

    // JSON Node names 
    private static final String TAG_ARTICLES = "articles"; 

    // Get the fields 
    private static final String TAG_ID = "id"; 
    private static final String TAG_TITLE = "title"; 
    private static final String TAG_SHORTTEXT = "shorttext"; 
    private static final String TAG_FULLTEXT = "fulltext"; 
    private static final String TAG_IMAGE = "image"; 
    private static final String TAG_DATE = "date"; 

    // articles JSONArray 
    JSONArray articles = null; 

    // Hashmap for ListView 
    ArrayList<HashMap<String, String>> articleList; 

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

     articleList = new ArrayList<HashMap<String, String>>(); 

     ListView lv = getListView(); 

     // Listview on item click listener 
     lv.setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       // getting values from selected ListItem 
       String title = ((TextView) view.findViewById(R.id.title)).getText().toString(); 
       String shorttext = ((TextView) view.findViewById(R.id.shorttext)).getText().toString(); 
       String fulltext = ((TextView) view.findViewById(R.id.fulltext)).getText().toString(); 
       String image = ((TextView) view.findViewById(R.id.image)).getText().toString(); 
       String date = ((TextView) view.findViewById(R.id.date)).getText().toString();    

       // Starting single article activity 
       Intent in = new Intent(getApplicationContext(), 
         SingleArticleActivity.class); 

       in.putExtra(TAG_TITLE, title); 
       in.putExtra(TAG_SHORTTEXT, shorttext); 
       in.putExtra(TAG_FULLTEXT, fulltext); 
       in.putExtra(TAG_IMAGE, image); 
       in.putExtra(TAG_DATE, date); 

       startActivity(in); 

      } 
     }); 

     // Calling async task to get json 
     new GetArticles().execute(); 

    } 

    /** 
    * Async task class to get json by making HTTP call 
    * */ 
    private class GetArticles extends AsyncTask<Void, Void, Void> { 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      // Showing progress dialog 
      pDialog = new ProgressDialog(MainActivity.this); 
      pDialog.setMessage("Please wait..."); 
      pDialog.setCancelable(false); 
      pDialog.show(); 

     } 

     @Override 
     protected Void doInBackground(Void... arg0) { 
      // Creating service handler class instance 
      ServiceHandler sh = new ServiceHandler(); 

      // Making a request to url and getting response 
      String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET); 

      Log.d("Response: ", "> " + jsonStr); 

      if (jsonStr != null) { 
       try { 
        JSONObject jsonObj = new JSONObject(jsonStr); 

        // Getting JSON Array node 
        articles = jsonObj.getJSONArray(TAG_ARTICLES); 

        // looping through All articles 
        for (int i = 0; i < articles.length(); i++) { 
         JSONObject c = articles.getJSONObject(i); 

         String id = c.getString(TAG_ID); 
         String title = c.getString(TAG_TITLE); 
         String shorttext = c.getString(TAG_SHORTTEXT); 
         String fulltext = c.getString(TAG_FULLTEXT);       
         String image = c.getString(TAG_IMAGE); 
         String date = c.getString(TAG_DATE); 


         // tmp hashmap for single article 
         HashMap<String, String> article = new HashMap<String, String>(); 

         // adding each child node to HashMap key => value 
         article.put(TAG_ID, id); 
         article.put(TAG_TITLE, title); 
         article.put(TAG_SHORTTEXT, shorttext); 
         article.put(TAG_FULLTEXT, fulltext);       
         article.put(TAG_IMAGE, image); 
         article.put(TAG_DATE, date); 

         // adding article to article list 
         articleList.add(article); 
        } 
       } catch (JSONException e) { 
        e.printStackTrace(); 
       } 
      } else { 
       Log.e("ServiceHandler", "Couldn't get any data from the url"); 
      } 

      return null; 
     } 

     @Override 
     protected void onPostExecute(Void result) { 
      super.onPostExecute(result); 
      // Dismiss the progress dialog 
      if (pDialog.isShowing()) 
       pDialog.dismiss(); 
      /** 
      * Updating parsed JSON data into ListView 
      * */ 
      ListAdapter adapter = new SimpleAdapter(

        MainActivity.this, articleList, 
        R.layout.list_item, new String[] { 
           TAG_TITLE, 
           TAG_SHORTTEXT, 
           TAG_FULLTEXT, 
           TAG_IMAGE, 
           TAG_DATE 
          }, 
          new int[] { 
           R.id.title, 
           R.id.shorttext, 
           R.id.fulltext, 
           R.id.image, 
           R.id.date        
          }); 

      setListAdapter(adapter);    

     } 

    } 

} 

**，我不知道在MainActivity文件添加我的脚本将图像添加到每个列表项目。

我已经得到了它的工作对SingleArticleActivity，但不能让它在项目列表**工作

感谢您的帮助

UPDATE

什么我尝试做的事：

foreach(ListItem in the List) { 

    ImageView thumb = (ImageView) findViewById(R.id.thumb); 
    UrlImageViewHelper.setUrlDrawable(thumb, "https://www.site.co.za/test.png"); 

} 

Answer 1

你必须只使用这一个..

ImageView thumb = (ImageView) findViewById(R.id.thumb); 
UrlImageViewHelper.setUrlDrawable(thumb, articleList.get(position).get(TAG_IMAGE)); 


CustomAdapter cdp = new CustomAdapter(YourActivityName.this , articleList); 
setListAdapter(adapter);  

现在让类CustomAdapter的与BaseAdapter延伸

public class CustomAdapter extends BaseAdapter { 

     ArrayList<HashMap<String, String>> list; 
     Context ctx; 

     public CustomAdapter(Context c , ArrayList<HashMap<String, String>> articleList){ 
      this.ctx = c; 

      this.list = articleList; 
     } 
    @Override 
    public int getCount() { 
     return list.size(); 
    } 

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

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

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     final ViewHolder holder; 
     View view = convertView; 
     if (view == null) { 
      view = getLayoutInflater().inflate(R.layout.list_item, 
        parent, false); 
      holder = new ViewHolder(); 
      assert view != null; 
      holder.imageView = (ImageView) view.findViewById(R.id.image); 

      view.setTag(holder); 

     } else { 
      holder = (ViewHolder) view.getTag(); 
     } 

      UrlImageViewHelper.setUrlDrawable(thumb, articleList.get(position).get(TAG_IMAGE)); 



     return view; 
    } 

    class ViewHolder { 
     ImageView imageView; 

    } 
} 

Answer 2

我在我的ListView适配器的getView方法中使用这种方法返回ns后来将其设置为我的ImageView的drawable。

public Drawable LoadImageFromWebOperations(String url) { 
    try { 
     InputStream is = (InputStream) new URL(url).getContent(); 
     Drawable d = Drawable.createFromStream(is, "src name"); 
     return d; 
    } catch (Exception e) { 
     return default_image; 
    } 
} 

希望这会有所帮助。

Answer 3

试试这个功能强大的图像下载和Android的缓存库Picasso

图像为Android应用程序添加了急需的上下文和视觉风格。毕加索允许在应用程序中轻松加载图像 - 通常只需一行代码！

Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);