從另一個類調用AsyncTask？

Question

您好，我從androidhive教程如下： http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/

我有這個asyntask作爲一個單獨的類，它做一些事情（在這裏：它從MySQL數據） - 我想從另一個調用此的AsyncTask類。所以每當我將這個類稱爲「LoadAllProducts」時，它就會完成這些工作。

我的第一個問題是，我怎麼能從另一個類中調用這個asyntask？

package com.example.androidhive; 

import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 

import org.apache.http.NameValuePair; 
import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import android.app.ListActivity; 
import android.app.ProgressDialog; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.TextView; 


public class LoadAllProducts extends AsyncTask<String, String, String> { 


    // Progress Dialog 
    private ProgressDialog pDialog; 

    // Creating JSON Parser object 
    JSONParser jParser = new JSONParser(); 

    ArrayList<HashMap<String, String>> productsList; 

    // url to get all products list 
    private static String url_all_products = "http://....url"; 

    // JSON Node names 
    private static final String TAG_SUCCESS = "success"; 
    private static final String TAG_PRODUCTS = "products"; 
    private static final String TAG_PID = "pid"; 
    private static final String TAG_NAME = "name"; 

    // products JSONArray 
    JSONArray products = null; 


     /** 
     * Before starting background thread Show Progress Dialog 
     * */ 
     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 

     productsList = new ArrayList<HashMap<String, String>>(); 
      pDialog = new ProgressDialog(AllProductsActivity.this); 
      pDialog.setMessage("Loading products. 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 = jParser.makeHttpRequest(url_all_products, "GET", params); 

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

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

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

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

         // Storing each json item in variable 
         String id = c.getString(TAG_PID); 
         String name = c.getString(TAG_NAME); 

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

         // adding each child node to HashMap key => value 
         map.put(TAG_PID, id); 
         map.put(TAG_NAME, name); 

         // adding HashList to ArrayList 
         productsList.add(map); 
        } 
       } else { 
        // no products found 
        // Launch Add New product Activity 
        Intent i = new Intent(getApplicationContext(), 
          NewProductActivity.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(); 


       } 
      }); 

     } 

    } 
} 

Answer 1

new LoadAllProducts().execute();應該可以調用這個類。