使用异步类删除 Listview 项目？

Question

我有我的列表视图，它显示我的本地数据库中的数据库条目。每次单击列表视图项时，我都想删除一行。然后计数器更新并刷新列表。有什么想法吗？

类：

public class ViewAllLocations extends ListActivity {

String id;

// Progress Dialog
private ProgressDialog pDialog;

// JSON parser class
JSONParser jsonParser = new JSONParser();

ArrayList<HashMap<String, String>> profileList;

// url to get all products list
private static String url_all_profile = "http://MYIP:8888/android_connect/get_all_location.php";
// url to delete product
private static final String url_delete_profile = "http://MYIP:8888/android_connect/delete_location.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_LOCATION = "Location";
private static final String TAG_ID = "id";
private static final String TAG_LATITUDE = "latitude";
private static final String TAG_LONGITUDE = "longitude";


// products JSONArray
JSONArray userprofile = null;

TextView locationCount;
int count = 0;
Button deleteLocation;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_view_all_locations);
    // Hashmap for ListView
    profileList = new ArrayList<HashMap<String, String>>();

    deleteLocation = (Button) findViewById(R.id.deleteLocation);
    locationCount = (TextView) findViewById(R.id.locationCount);

    // Loading products in Background Thread
        new LoadAllLocation().execute();



  // Get listview
        ListView lo = getListView();
        lo.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                new DeleteLocation().execute();
                profileList.remove(position);
            }
        });
    }

    /*****************************************************************
     * Background Async Task to Delete Product
     * */
    class DeleteLocation extends AsyncTask<String, String, String> {


        /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(ViewAllLocations.this);
        pDialog.setMessage("Deleting Location...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Deleting product
     * */
    protected String doInBackground(String... args) {

        // Check for success tag
        int success;
        try {
            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("id", id));

            // getting product details by making HTTP request
            JSONObject json = jsonParser.makeHttpRequest(
                    url_delete_profile, "POST", params);

            // check your log for json response
            Log.d("Delete Product", json.toString());

            // json success tag
            success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
                // product successfully deleted
                // notify previous activity by sending code 100
               // Intent i = getIntent();
                // send result code 100 to notify about product deletion
                //setResult(100, i);
                Toast.makeText(getApplicationContext(), "Location Deleted",
                        Toast.LENGTH_SHORT).show();
                finish();
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }


    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog once product deleted
        pDialog.dismiss();

    }

}

/**
 * Background Async Task to Load all product by making HTTP Request
 * */
class LoadAllLocation extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(ViewAllLocations.this);
        pDialog.setMessage("Loading Locations. Please wait...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
    }

    /**
     * getting All products from url
     * */
    protected String doInBackground(String... args) {
        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        // getting JSON string from URL
        JSONObject json = jsonParser.makeHttpRequest(url_all_profile, "GET", params);

        // Check your log cat for JSON reponse
        Log.d("All Profiles: ", json.toString());

        try {
            // Checking for SUCCESS TAG
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // products found
                // Getting Array of Products
                userprofile = json.getJSONArray(TAG_LOCATION);

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

                    // Storing each json item in variable
                    String id = c.getString(TAG_ID);
                    String latitude = c.getString(TAG_LATITUDE);
                    String longitude = c.getString(TAG_LONGITUDE);


                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_ID, id);
                    map.put(TAG_LATITUDE, latitude);
                    map.put(TAG_LONGITUDE, longitude);


                    // adding HashList to ArrayList
                    profileList.add(map);
                }
            } else {
                // no products found
                // Launch Add New product Activity
                Intent i = new Intent(getApplicationContext(),
                        UserLocation.class);
                // Closing all previous activities
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog after getting all products
        pDialog.dismiss();
        // updating UI from Background Thread
        runOnUiThread(new Runnable() {
            public void run() {
                /**
                 * Updating parsed JSON data into ListView
                 * */


                 ListAdapter adapter = new SimpleAdapter(
                        ViewAllLocations.this, profileList,
                        R.layout.locationitem, new String[] { TAG_ID,
                        TAG_LATITUDE, TAG_LONGITUDE},
                        new int[] { R.id.id, R.id.latitude, R.id.longitude});
                // updating listview
                setListAdapter(adapter);
                locationCount.setText(""+profileList.size());

            }
        });

    }

}

Answer 1

当您成功删除产品后，您还需要从列表中删除该产品。

使用yourList.remove(position) 刷新您的列表。