将 JSON 数组数据显示为列表视图

Question

我有一个要显示的 JSON 数组。我能够成功地将其显示为文本视图，但并未列出所有数据。只有最后一个。这是“记住明天我们将在我们的办公室分发爆米花和一些水瓶！周二，我们会给你免费早餐！请注册成为 CSA 志愿者来获取免费食物！”。我相信将其列为列表视图会更有效，但是，我从在线网站上阅读的所有内容都不起作用。

DefaultHttpClient   httpclient = new DefaultHttpClient(new BasicHttpParams());
HttpPost httppost = new HttpPost("http://ec2-54-213-155-95.us-west-2.compute.amazonaws.com/notices.php");
// Depends on your web service
httppost.setHeader("Content-type", "application/json");


InputStream inputStream = null;
String result = null;
try {
    HttpResponse response = httpclient.execute(httppost);           
    HttpEntity entity = response.getEntity();

    inputStream = entity.getContent();
    // json is UTF-8 by default
    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
    StringBuilder sb = new StringBuilder();

    String line = null;
    while ((line = reader.readLine()) != null)
    {
        sb.append(line + "\n");
    }
    result = sb.toString();
} catch (Exception e) { 
    // Oops
}
finally {
    try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
}

try {
    JSONObject jObject = new JSONObject(result);
    JSONArray jsonArray = jObject.getJSONArray("notices");        
    for(int i = 0; i < jsonArray.length(); i++) {
        String arrayString = jsonArray.getString(i);
        Log.d("notices", arrayString); 
        ListView listView1 = (ListView) findViewById(R.id.listView1);


} catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

基本上我想将其显示为列表视图！

Answer 1

首先，您应该考虑在异步任务中执行此操作。

第二次在 lsitview 中显示它相对容易。你可以这样做：

public class YourActivity extends Activiy{
   public void getJson(String selection, String url) { 
           new LoadJsonTask().execute( selection, url);

   }
   private class LoadJsonTask extends AsyncTask<String, Void, ArrayList<HashMap<String, String>> > {
       ProgressDialog dialog ;
       protected void onPreExecute (){
            dialog = ProgressDialog.show(YourActivity.this ,"title","message");

       }
       protected ArrayList<HashMap<String, String>> doInBackground (String... params){
           return doGetJson(params[0],params[1]);
       }
       protected void onPostExecute(ArrayList<HashMap<String, String>> mylist){

            ListAdapter adapter = new JsonAdapter(YourActivity.this, mylist, R.layout.list,
              new String[] { "name", "text", "ts"}, new int[] { R.id.item_title,
                R.id.item_subtitle, R.id.timestamp});
            setListAdapter(adapter);
            dialog.dismiss();
       }
    }

 public ArrayList<HashMap<String, String>> doGetJson(String selection, String url) {
     JSONObject json = null;
     String formatedcat = selection.toLowerCase();
     ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
     json = JSONfunctions
        .getJSONfromURL(url);
     try {
    //the array title that you parse
    JSONArray category = json.getJSONArray(formatedcat);
    for (int i = 0; i < category.length(); i++) {               
        HashMap<String, String> map = new HashMap<String, String>();
        JSONObject c = category.getJSONObject(i);
        map.put("id", String.valueOf(i));
        map.put("name",
                c.getString("title"));
        //map.put("text",c.getString("title"));
        map.put("ts",c.getString("run_date") );
        map.put("image","http:"+c.getString("url"));
        mylist.add(map);
    }
} catch (JSONException e) {

}
   return mylist;
  ....   
}

代码的重要部分是：

 ListAdapter adapter = new JsonAdapter(YourActivity.this, mylist, R.layout.list,
              new String[] { "name", "text", "ts"}, new int[] { R.id.item_title,
                R.id.item_subtitle, R.id.timestamp});
            setListAdapter(adapter);

这是您将字符串数组设置为从 json 对象创建的哈希图并使用它设置列表适配器的地方，以便列表视图将显示所有相关数据。通过question 了解更多信息。