假设JSON响应中没有图像，但数据将存在，然后无法在列表视图中显示图像和数据

2 回答

• 1

  这是因为你在一个单独的 try-catch 块中做了所有事情 . 当没有图像时，它会抛出一个错误，跳出你的循环 . 您应该单独添加 try-catch 块来读取图像：

  ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
  
  
      // Creating JSON Parser instance
              JSONParser jParser = new JSONParser();
  
              // getting JSON string from URL
              JSONObject json = jParser.getJSONFromUrl(URL);
              try {
                  JSONArray posts = json.getJSONArray(KEY_POSTS);
  
      // looping through all song nodes <song>
              for(int i = 0; i < posts.length(); i++){
                  JSONObject c = posts.getJSONObject(i);
                  // Storing each json item in variable
                  String id = c.getString(KEY_ID);
                  String title = c.getString(KEY_TITLE);
                  String date = c.getString(KEY_DATE);
                  String content = c.getString(KEY_CONTENT);
                  // to remove all <P> </p> and 
   and replace with ""
                   content = content.replace("
  ", "");
                   content = content.replace("<p>", "");
                   content = content.replace("</p>", "");
  
                  //authornumber is agin  JSON Object
                  JSONObject author = c.getJSONObject(KEY_AUTHOR);
                  String name = author.getString(KEY_NAME);
  
                  String url = null;
                  String slug = null;
                  try {
                  JSONArray atta = c.getJSONArray("attachments");
                  for(int j = 0; j < atta.length(); j++){
                      JSONObject d = atta.getJSONObject(j);
  
                      slug = d.getString(KEY_SLUG);
  
                      JSONObject images = d.getJSONObject(KEY_IMAGES);
  
                      JSONObject thumbnail = images.getJSONObject(KEY_THUMB_URL);
                      url = thumbnail.getString(KEY_URL);
                  } catch (Exception e) {}
  
  
  
  
          // creating new HashMap
          HashMap<String, String> map = new HashMap<String, String>();
  
          // adding each child node to HashMap key => value
          map.put(KEY_ID, id);
          map.put(KEY_TITLE, title);
          map.put(KEY_DATE, date);
          map.put(KEY_NAME, name);
          map.put(KEY_CONTENT, content);
          map.put(KEY_SLUG, slug);
          map.put(KEY_URL, url);
  
  
          // adding HashList to ArrayList
          songsList.add(map);
              }   }
              } catch (JSONException e) {
                  e.printStackTrace();
  
                  }
  
  
      list=(ListView)findViewById(android.R.id.list);
      list.setOnScrollListener(this);
      // Getting adapter by passing json data ArrayList
      adapter=new LazyAdapter(this, songsList);        
      list.setAdapter(adapter);
  

  回复于 2024-04-28T14:41:27+08:00
• 1

  在listAdapter的getView（）方法中检查url值 . 如果它为空或为空，则显示一些存根图像（某些图像，如无图像可用 - >将其保存在res中） .

  回复于 2024-04-28T14:41:27+08:00