您好，我想开发一个带有缩略图和产品名称的产品列表。我削减了产品名称，JSON但我想在左侧添加缩略图。是否可以AsyncTask与图像和Strings. 我该怎么做？如何将图像和文本一起返回。我想在如下所示的代码中调用图像：
package com.eticaret.hakan;
import java.io.BufferedInputStream;
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.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class ProductActivity extends ListActivity {
int intid;
// 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://10.0.2.2/projeler/e-ticaret/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "urunler";
private static final String TAG_PID = "pid";
private static final String TAG_PNAME = "pname";
private static final String TAG_PPRICE = "pprice";
private static final String TAG_PDESCRIPTION = "pdescription";
private static final String TAG_CREATEDAT = "created_at";
private static final String TAG_CATID = "cat_Id";
// products JSONArray
JSONArray products = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.products);
Bundle extras = getIntent().getExtras();
String id = extras.getString("cat_Id");
intid=Integer.parseInt(id);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
Details.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit Product Activity
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ProductActivity.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_PNAME);
String price = c.getString(TAG_PPRICE);
String description = c.getString(TAG_PDESCRIPTION);
String created_at = c.getString(TAG_CREATEDAT);
String catid = c.getString(TAG_CATID);
int intcatid=Integer.parseInt(catid);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
if(intcatid==intid){
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_PNAME, name);
map.put(TAG_PPRICE, price);
map.put(TAG_PDESCRIPTION, description);
map.put(TAG_CREATEDAT, created_at);
// adding HashList to ArrayList
productsList.add(map);
}
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
ProductActivity.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(
ProductActivity.this, productsList,
R.layout.plist_item, new String[] { TAG_PID,
TAG_PNAME,TAG_PPRICE},
new int[] { R.id.pid, R.id.pname,R.id.pprice});
// updating listview
setListAdapter(adapter);
}
});
}
}
}