Android 当我们点击listview中的项目时，我们如何获得该项目的id

我有一个json，其中我有product_id和product_名称，通过listview中显示的json产品，现在我希望当单击项目时，该产品的id应该显示在toast中。我是android新手，我无法做到这一点 谁能告诉我怎么做

 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);

} }

服务手柄等级代码：

 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;

}

医院在listview中显示的医院活动代码我希望不是所有医院都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);




    }
}

在ItemClick方法上，您可以添加此项以获取产品的id

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

---

公共类CityNameActivity扩展了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);
        }
    }

---

}

为什么每次都点击服务。根据我的意见，不要在McClick中呼叫服务。启动活动或应用程序启动异步任务并将数据传递给列表视图时

请查找下面的代码。我只是重构一些东西，所以请让我，如果有一些东西错了

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);




        }
    }
}

---

在我的代码中只显示姓名您是否需要该代码我发布了代码中只显示姓名现在我想执行代码以获取itemPost的id您的适配器类也没有任何适配器类您的城市名称和id是否唯一？请执行下面的操作对于int i=0；i.长度；i++{JSONObject c=Cities.GetJSONObject；cityListWithId无法重新映射cityListWithId=new HashMap；在您启动classprint标记名和tagId并查看您获得的标记名后，这一行应该位于顶部，但您的城市中的tagId为Null\u id为Null，请清楚地解释您的问题是什么。？如果它为null可能是您解析错误或您没有id值。我怎么知道id是什么意思？当我单击“解析是正确的”时，请调试并与jsoni WARD get only id进行交叉检查。from cities正在显示这是我给出的代码应该做的。当您在hashmap列表中存储您的值时，获取has该位置的hmap和从mapid获取id已显示在toast中，但我有另一项任务，您能帮助我吗