当我们点击列表视图中的项目，然后我们如何获得该项目的ID

-3

我有一个json，其中我有product_id和product_name通过Json产品显示在列表视图中，现在我希望当点击该项目时，然后该产品的id应该在烤面包中显示。我是新到Android我无法做到这一点谁能告诉我，我怎么能做到这一点，请当我们点击列表视图中的项目，然后我们如何获得该项目的ID

public class CityNameActivity extends ListActivity{ 
ListView list; 

private ProgressDialog pDialog; 
// URL to get Cities JSON 
private static String url = "http://14.140.200.186/Hospital/get_city.php"; 
// JSON Node names 
private static final String TAG_CITIES = "Cities"; 
//private static final String TAG_ID = "id"; 
private static final String TAG_NAME = "city_name"; 
// Cities JSONArray 
JSONArray Cities = null; 
// Hashmap for ListView 
ArrayList<HashMap<String, String>> citylist; 
//ArrayList<String> citylist; 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.cityname_activity_main); 
    ListView listView=getListView(); 
    citylist = new ArrayList<HashMap<String, String>>(); 
    // list.setOnClickListener(this); 
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
           int position, long id) { 

      Intent in = new Intent(getApplicationContext(), 
        Specialities_Activity.class); 

      startActivity(in);} 
     }); 
      new GetCities().execute(); 
     } 
/** 
* Async task class to get json by making HTTP call 
* */ 
private class GetCities extends AsyncTask<Void, Void, Void> { 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     // Showing progress dialog 
     pDialog = new ProgressDialog(CityNameActivity.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 
       Cities = jsonObj.getJSONArray(TAG_CITIES); 

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

        //String id = c.getString(TAG_ID); 
        String name = c.getString(TAG_NAME); 
        HashMap<String, String> Cities = new HashMap<String, String>(); 
        Cities.put(TAG_NAME, name); 


        // adding contact to Cities list 
        citylist.add(Cities); 


       } 
      } 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(); 
     /**`enter code here` 
     * Updating parsed JSON data into ListView 
     * */ 
     ListAdapter adapter = new SimpleAdapter(CityNameActivity.this, citylist, R.layout.city_list_item, new String[] { TAG_NAME}, new int[] { R.id.name}); 
     setListAdapter(adapter);

} }

服务代码Handlerclass：中

public class ServiceHandler { 

static String response = null; 
public final static int GET = 1; 
public final static int POST = 2; 

public ServiceHandler() { 

} 

/* 
* Making service call 
* @url - url to make request 
* @method - http request method 
* */ 
public String makeServiceCall(String url, int method) { 
    return this.makeServiceCall(url, method, null); 
} 

/* 
* Making service call 
* @url - url to make request 
* @method - http request method 
* @params - http request params 
* */ 
public String makeServiceCall(String url, int method, 
     List<NameValuePair> params) { 
    try { 
     // http client 
     DefaultHttpClient httpClient = new DefaultHttpClient(); 
     HttpEntity httpEntity = null; 
     HttpResponse httpResponse = null; 

     // Checking http request method type 
     if (method == POST) { 
      HttpPost httpPost = new HttpPost(url); 
      // adding post params 
      if (params != null) { 
       httpPost.setEntity(new UrlEncodedFormEntity(params)); 
      } 

      httpResponse = httpClient.execute(httpPost); 

     } else if (method == GET) { 
      // appending params to url 
      if (params != null) { 
       String paramString = URLEncodedUtils 
         .format(params, "utf-8"); 
       url += "?" + paramString; 
      } 
      HttpGet httpGet = new HttpGet(url); 

      httpResponse = httpClient.execute(httpGet); 

     } 
     httpEntity = httpResponse.getEntity(); 
     response = EntityUtils.toString(httpEntity); 

    } catch (UnsupportedEncodingException e) { 
     e.printStackTrace(); 
    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    return response; 

}

代码医院活动在哪里医院显示在列表视图我希望不是所有的医院显示只显示特定城市的医院

public class HospitalList_Activity extends ListActivity { 
private ProgressDialog pDialog; 
// URL to get Hospitals JSON 
private static String url = "http://14.140.200.186/hospital/get_hospital.php"; 
// JSON Node names 
private static final String TAG_HOSPITAL = "Hospitals"; 
//private static final String TAG_ID = "id"; 
private static final String TAG_NAME = "hospital_name"; 
// Hospitals JSONArray 
JSONArray Hospitals = null; 
// Hashmap for ListView 
ArrayList<HashMap<String, String>> hospitallist; 
//ArrayList<String> citylist; 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_hospital_list_); 
    ListView listView=getListView(); 
    hospitallist = new ArrayList<HashMap<String, String>>(); 
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
           int position, long id) { 

      Intent in = new Intent(getApplicationContext(), Specialities_Activity.class); 
      startActivity(in); 
     } 
    }); 
    new GetHospitals().execute(); 
} 
/** 
* Async task class to get json by making HTTP call 
* */ 
private class GetHospitals extends AsyncTask<Void, Void, Void> { 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     // Showing progress dialog 
     pDialog = new ProgressDialog(HospitalList_Activity.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 
       Hospitals = jsonObj.getJSONArray(TAG_HOSPITAL); 

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

        //String id = c.getString(TAG_ID); 
        String name = c.getString(TAG_NAME); 
        HashMap<String, String> Hospitals = new HashMap<String, String>(); 
        Hospitals.put(TAG_NAME, name); 


        // adding contact to Cities list 
        hospitallist.add(Hospitals); 
       } 
      } 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(); 
     /**`enter code here` 
     * Updating parsed JSON data into ListView 
     * */ 
     ListAdapter adapter = new SimpleAdapter(HospitalList_Activity.this, hospitallist, R.layout.hospital_list_item, new String[] { TAG_NAME}, new int[] { R.id.name}); 
     setListAdapter(adapter); 




    } 
}

来源

2016-02-29 Tom

你的代码在哪里？ –

在我的代码中只显示您需要的代码 – Tom

发布您的代码。 – Jas

公共类CityNameActivity扩展ListActivity {

ListView list; 
    Map <String, String> cityListWithId = new HashMap<String, String>(); 
    private ProgressDialog pDialog; 
    // URL to get Cities JSON 
    private static String url = "http://14.140.200.186/Hospital/get_city.php"; 
    // JSON Node names 
    private static final String TAG_CITIES = "Cities"; 
    private static final String TAG_ID = "city_id"; 
    private static final String TAG_NAME = "city_name"; 
    // Cities JSONArray 
    JSONArray Cities = null; 
    // Hashmap for ListView 
    ArrayList<HashMap<String, String>> citylist; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.cityname_activity_main); 
     ListView listView=getListView(); 
     citylist = new ArrayList<HashMap<String, String>>(); 
     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       //String tagname = ((TextView) findViewById(R.id.name)).getText().toString(); 
       Map<String, String> tempHashmap = (Map<String, String>) parent.getItemAtPosition(position); 
       String tagName = tempHashmap.get(TAG_NAME); 
       System.out.println("tagname" + tagName); 
       String tagId = (String)cityListWithId.get(tagName); 

       System.out.println("tagId" + tagId); 
       Toast.makeText(CityNameActivity.this, tagId,Toast.LENGTH_SHORT).show(); 

      } 
      }); 
       new GetCities().execute(); 
      } 
    /** 
    * Async task class to get json by making HTTP call 
    * */ 
    private class GetCities extends AsyncTask<Void, Void, Void> { 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      // Showing progress dialog 
      pDialog = new ProgressDialog(CityNameActivity.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 
        Cities = jsonObj.getJSONArray(TAG_CITIES); 

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

         //String id = c.getString(TAG_ID); 
         String name = c.getString(TAG_NAME); 
         cityListWithId.put(c.getString(TAG_NAME), c.getString(TAG_ID)); 
         HashMap<String, String> Cities = new HashMap<String, String>(); 
         Cities.put(TAG_NAME, name); 

         // adding contact to Cities list 
         citylist.add(Cities); 
        } 
       } 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(); 
      /**`enter code here` 
      * Updating parsed JSON data into ListView 
      * */ 
      ListAdapter adapter = new SimpleAdapter(CityNameActivity.this, citylist, R.layout.city_list_item, new String[] { TAG_NAME}, new int[] { R.id.name}); 
      setListAdapter(adapter); 
     } 
    }

}

来源

2016-02-29 06:32:30

c无法解析 – Tom

做到以下（int i = 0; i

cityListWithId无法重新生成 – Tom

在ItemClick()方法，你可以添加这个来获得产品的id。

HashMap<String,String> data = cityList.get(position); 
//position is the paramater from ItemClick 
String id = data.get("your key for Id");

来源

2016-02-29 06:29:02

其中id将显示平均值我可以知道id是您的 – Tom

您的city_id为null – Tom

您能否请您清楚解释您的问题是什么。如果它是空的可能是你解析错误或者你没有id值。你是什么意思，我怎么知道id是这样的？调试和交叉检查与json –

为什么你每次都能够服务。根据我的观点，不要在onItemClick中调用服务。当您启动活动或应用程序启动异步任务并将数据传递到列表视图时。

请在下面找到代码。我只是重构一些东西，所以请让我，如果有什么不对的地方

public class CityNameActivity extends ListActivity 
{ 
    private ProgressDialog pDialog; 
    // URL to get Cities JSON 
    private static String url = "http://14.140.200.186/Hospital/get_city.php"; 
    // JSON Node names 
    private static final String TAG_CITIES = "Cities"; 
    //private static final String TAG_ID = "id"; 
    private static final String TAG_NAME = "city_name"; 
    // Cities JSONArray 
    JSONArray Cities = null; 
    // Hashmap for ListView 
    ArrayList<HashMap<String, String>> citylist; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

     new GetCities().execute(); 

     ListView listView=getListView(); 
     citylist = new ArrayList<HashMap<String, String>>(); 
     // list.setOnClickListener(this); 
     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
       if(citylist!=null && !citylist.isEmpty()) 
       { 
        Toast.makeText(CityNameActivity.this,""+citylist.get(position).get(TAG_NAME).toString(),Toast.LENGTH_SHORT).show(); 
       } 
      } 
     }); 

     new GetCities().execute(); 
    } 




    private class GetCities extends AsyncTask<Void, Void, Void> { 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      // Showing progress dialog 
      pDialog = new ProgressDialog(CityNameActivity.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 
        Cities = jsonObj.getJSONArray(TAG_CITIES); 

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

         //String id = c.getString(TAG_ID); 
         String name = c.getString(TAG_NAME); 
         HashMap<String, String> Cities = new HashMap<String, String>(); 
         Cities.put(TAG_NAME, name); 


         // adding contact to Cities list 
         citylist.add(Cities); 


        } 
       } 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(); 
      /**`enter code here` 
      * Updating parsed JSON data into ListView 
      * */ 
      ListAdapter adapter = new SimpleAdapter(CityNameActivity.this, citylist, R.layout.city_list_item, new String[] { TAG_NAME}, new int[] { R.id.name}); 
      setListAdapter(adapter); 




     } 
    } 
}

来源

2016-02-29 06:55:57

当我们点击列表视图中的项目，然后我们如何获得该项目的ID

回答

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