Question

我以response格式从服务器获取json。如何在listview中显示回复。

代码：

public class MainActivity extends Activity {
    private static String url = "http://api.androidhive.info/contacts/";

    @SuppressLint("NewApi")
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        InputStream is = null;
        StrictMode.setThreadPolicy(policy);

        new JSONParse().execute();

    }

    private class JSONParse extends AsyncTask<String, String, JSONObject> {
        private ProgressDialog pDialog;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();

            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Getting Data ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();

        }

        @Override
        protected JSONObject doInBackground(String... args) {

            JSONParser jParser = new JSONParser();

            // Getting JSON from URL
            JSONObject json = jParser.getJSONFromUrl(url);
            return json;
        }

        @Override
        protected void onPostExecute(JSONObject json) {
            pDialog.dismiss();

        }
    }
}

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();           

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

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
            System.out.println("sb:"+sb);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

Answer 1

这不需要

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
            .permitAll().build();
InputStream is = null;
StrictMode.setThreadPolicy(policy);

同样@SuppressLint("NewApi")表示您抑制了棉绒警告。有些功能仅适用于新api。请检查你的min sdk版本。

将列表中的响应显示在listview

中

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <!-- Main ListView 
         Always give id value as list(@android:id/list)
    -->
    <ListView
        android:id="id/list" // id is list
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

然后在onCreate

ListView lv;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    lv= (ListView) findViewById(R.id.list);
    new JSONParse().execute();
}

更改此

   private class JSONParse extends AsyncTask<String, String, JSONObject>

到

   private class JSONParse extends AsyncTask<String, String, ArrayList<HashMap<String, String>>>

确保您拥有这些

public class MainActivity extends Activity {

  private static String url = "http://api.androidhive.info/contacts/";
  private static final String TAG_CONTACTS = "contacts";
  private static final String TAG_ID = "id";
  private static final String TAG_NAME = "name";
  private static final String TAG_EMAIL = "email";
  private static final String TAG_ADDRESS = "address";
  private static final String TAG_GENDER = "gender";
  private static final String TAG_PHONE = "phone";
  private static final String TAG_PHONE_MOBILE = "mobile";
  private static final String TAG_PHONE_HOME = "home";
  private static final String TAG_PHONE_OFFICE = "office";

在doInbackground中你需要解析json

   @Override
    protected ArrayList<HashMap<String, String>> doInBackground(String... args) {
        ArrayList<HashMap<String, String>> contactList= new ArrayList<HashMap<String,String>>();
        JSONParser jParser = new JSONParser();

        // Getting JSON from URL
        JSONObject json = jParser.getJSONFromUrl(url);
          try {
                contacts = json.getJSONArray(TAG_CONTACTS);

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

                    String id = c.getString(TAG_ID);
                    String name = c.getString(TAG_NAME);
                    String email = c.getString(TAG_EMAIL);
                    String address = c.getString(TAG_ADDRESS);
                    String gender = c.getString(TAG_GENDER);

                    // Phone node is JSON Object
                    JSONObject phone = c.getJSONObject(TAG_PHONE);
                    String mobile = phone.getString(TAG_PHONE_MOBILE);
                    String home = phone.getString(TAG_PHONE_HOME);
                    String office = phone.getString(TAG_PHONE_OFFICE);

                    // tmp hashmap for single contact
                    HashMap<String, String> contact = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    contact.put(TAG_ID, id);
                    contact.put(TAG_NAME, name);
                    contact.put(TAG_EMAIL, email);
                    contact.put(TAG_PHONE_MOBILE, mobile);

                    // adding contact to contact list
                    contactList.add(contact);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        return contactList;
    }

然后

   @Override
    protected void onPostExecute(ArrayList<HashMap<String, String>>  result) {
        super.onPostExecute(result);
        // Dismiss the progress dialog
        if (pDialog.isShowing())
            pDialog.dismiss();
        ListAdapter adapter = new SimpleAdapter(
                MainActivity.this, result,
                R.layout.list_item, new String[] { TAG_NAME, TAG_EMAIL,
                        TAG_PHONE_MOBILE }, new int[] { R.id.name,
                        R.id.email, R.id.mobile });

        lv.setAdapter(adapter);
    }

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="10dp"
    android:paddingLeft="10dp"
    android:paddingRight="10dp" >

    <!-- Name Label -->

    <TextView
        android:id="@+id/name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:paddingTop="6dip"
        android:textColor="#43bd00"
        android:textSize="16sp"
        android:textStyle="bold" />

    <!-- Email label -->
    <TextView
        android:id="@+id/email"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:textColor="#acacac" />

    <!-- Mobile number label -->
    <TextView
        android:id="@+id/mobile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:text="Mobile: "
        android:textColor="#5d5d5d"
        android:textStyle="bold" />

</LinearLayout>

如何在列表视图中显示JSON响应

1 个答案: