java如何从ClickListener上的listview获取id值

1 月 Questions & Answers 54

我想从listview获取id，而不是位置。id在JSON文件中，所以当我在listview中显示数据时，当我单击它时，我从JSON文件中获取该驱动程序的id

[{lastName=wdkj fsj, firstName=jf jfn, id=1}, {lastName=singh, firstName=sunny, id=2}]

public class DriverData extends AppCompatActivity { private String TAG = DriverData.class.getSimpleName(); ArrayAdapter<String> adapter; private ProgressDialog pDialog; private ListView lv; // URL to get contacts JSON private static String url = "http://54.148.120.200:3000/getDrivers"; ArrayList<HashMap<String, String>> contactList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.driver_data); contactList = new ArrayList<>(); lv = (ListView) findViewById(R.id.simpleListView); new DriverData.GetContacts().execute(); } /** * Async task class to get json by making HTTP call */ private class GetContacts extends AsyncTask<Void, Void, Void> { @Override protected void onPreExecute() { super.onPreExecute(); // Showing progress dialog pDialog = new ProgressDialog(DriverData.this); pDialog.setMessage("Please wait..."); pDialog.setCancelable(false); pDialog.show(); } @Override protected Void doInBackground(Void... arg0) { HttpHandler sh = new HttpHandler(); // Making a request to url and getting response String jsonStr = sh.makeServiceCall(url); Log.e(TAG, "Response from url: " + jsonStr); if (jsonStr != null) { try { JSONObject jsonObj = new JSONObject(jsonStr); // Getting JSON Array node JSONArray contacts = jsonObj.getJSONArray("drivers"); // looping through All Contacts for (int i = 0; i < contacts.length(); i++) { JSONObject c = contacts.getJSONObject(i); String id = c.getString("id"); JSONObject user = c.getJSONObject("user"); String firstName = user.getString("firstName"); String lastName = user.getString("lastName"); // Phone node is JSON Object // tmp hash map for single contact HashMap<String, String> contact = new HashMap<>(); // adding each child node to HashMap key => value contact.put("id", id); contact.put("firstName", firstName); contact.put("lastName", lastName); // adding contact to contact list contactList.add(contact); } } catch (final JSONException e) { Log.e(TAG, "Json parsing error: " + e.getMessage()); runOnUiThread(new Runnable() { @Override public void run() { Toast.makeText(getApplicationContext(), "Json parsing error: " + e.getMessage(), Toast.LENGTH_LONG) .show(); } }); } } else { Log.e(TAG, "Couldn't get json from server."); runOnUiThread(new Runnable() { @Override public void run() { Toast.makeText(getApplicationContext(), "Couldn't get json from server. Check LogCat for possible errors!", Toast.LENGTH_LONG) .show(); } }); } System.out.println(contactList); 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( DriverData.this, contactList, R.layout.list_item, new String[]{"firstName", "lastName" }, new int[]{R.id.name, R.id.lastName}); lv.setAdapter(adapter); lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) { } }); } } }

lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) { String id=contactList.get(position).get("id"); } });

# 2 楼答案

首先，创建POJO模型以保存对象并轻松使用它们

public class Contact {

    private String id;
    private String lastName;
    private String firstName;

    public Contact(String id, String lastName, String firstName) {
        this.id = id;
        this.lastName = lastName;
        this.firstName = firstName;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
}

这只是一个POJO模型类，但是如果您想获得更多关于它的信息，您可以按照下面的link

注意：变量应该是private，方法应该是public

然后，最好创建自己的自定义适配器

public class ListAdapter extends ArrayAdapter<Item> {

    private List<Contact> contactList;

    public ListAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    public ListAdapter(Context context, int resource, List<Contact> contactList) {
        super(context, resource, contactList);
        this.contactList = contactList;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View v = convertView;

        if (v == null) {
            LayoutInflater vi;
            vi = LayoutInflater.from(getContext());
            v = vi.inflate(R.layout.itemlistrow, null);
        }

        Item p = getItem(position);

        if (p != null) {
            TextView tvId = (TextView) v.findViewById(R.id.id);
            TextView tvLastName = (TextView) v.findViewById(R.id.lastName);
            TextView tvFirstName = (TextView) v.findViewById(R.id.firstName);

            tvId.setText(contactList.getId()); // this will show ID
            tvLastName.setText(contactList.getLastName()); 
            tvFirstName.setText(contactList.getFirstName());

        }

        return v;
    }

}

然后，从JSON链接获取所有数据后，将数据发送给构造函数。我将更新您的来源：

      try {
                contactList = new ArrayList<Contact>;
                JSONObject jsonObj = new JSONObject(jsonStr);

                // Getting JSON Array node
                JSONArray contacts = jsonObj.getJSONArray("drivers");

                // looping through All Contacts
                for (int i = 0; i < contacts.length(); i++) {
                    Contact contact = new Contact();

                    JSONObject c = contacts.getJSONObject(i);


                    JSONObject user = c.getJSONObject("user");
                    contact.setId(c.getString("id"));
                    contact.setFirstName(user.getString("firstName"));
                    contact.setLastName(user.getString("lastName"));

                    contactList.add(contact);


                }
            }

同时更新onPostExecute()方法

@Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);

            // Dismiss the progress dialog
            if (pDialog.isShowing())
                pDialog.dismiss();


            //System.out.println(contactList.size());

            /**
             * Updating parsed JSON data into ListView
             * */

            ListAdapter adapter = new ListAdapter(
                    getApplicationContext(), R.layout.list_item, contactList);
            lv.setAdapter(adapter);
        }

如果您有任何错误，请在此处进行评论，我将更新。尚未测试，但我认为这将有帮助。享受吧

Python中文网

有 Java 编程相关的问题?

java如何从ClickListener上的listview获取id值

共 (2) 个答案

# 1 楼答案

# 2 楼答案