我在android中有一个应用程序，可以从远程服务器获取数据并将其显示在ListFragment上。它成功获取了我在LogCat上显示的数据，但它没有显示在ListFragment所在的Activity本身上。它只是显示加载圈，无论我等多久它仍然做同样的事情。我使用httprequest获取数据并使用AsyncTask来获取它们。
以下是主要活动代码：
package com.thesis.menubook;
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.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
public class MenuMain extends ListActivity {
JSONParser jsonParser = new JSONParser();
ArrayList<HashMap<String, String>> categoryList = new ArrayList<HashMap<String, String>>();
private ProgressDialog pDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu_main);
// Populate Category List from database
new GetCategories().execute();
//set list on click listener for category
// on category list click update fragment using dbase query
// set swipe listener
// on swipe update fragment using dbase query
// set add button listener
// on click add to order list list adapter
// set order list listener
// on click remove from list
// set send button listener
// update remote database using order list
}
class GetCategories extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MenuMain.this);
pDialog.setMessage("Loading Categories. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* Getting product details in background thread
* */
protected String doInBackground(String... param) {
Bundle b = getIntent().getExtras();
String ipaddress = b.getString("IPAddress");
List<NameValuePair> params = new ArrayList<NameValuePair>();
Log.d("IP ADDRESS", ipaddress +" ");
JSONObject json = jsonParser.makeHttpRequest("http://"+ipaddress+"/MenuBook/selectCategories.php", "GET", params);
// Check your log cat for JSON reponse
Log.d("All Categories: ", json.toString() + " ");
int num = 1;
try {
// Checking for SUCCESS TAG
int success = json.getInt("success");
if (success == 1) {
// products found
// Getting Array of Products
JSONArray category_list = json.getJSONArray("category_list");
// looping through All Products
for (int j = 1; j < category_list.length(); j++) {
JSONObject c = category_list.getJSONObject(j);
// Storing each json item in variable
String category = c.getString("category");
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put("category", category);
Log.d("category #"+num+"", category + " ");
num = num + 1;
// adding HashList to ArrayList
if(categoryList.contains(map) != true)
{
categoryList.add(map);
}
Log.d("Category List", categoryList.toString() + " ");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
@Override
protected void onPostExecute(String result) {
pDialog.dismiss();
ArrayAdapter<ArrayList<HashMap<String, String>>> arrayAdapter = new ArrayAdapter<ArrayList<HashMap<String, String>>>(MenuMain.this, R.layout.activity_menu_category);
arrayAdapter.add(categoryList);
if(arrayAdapter.isEmpty() == true)
{
setListAdapter(null);
}
else
{
setListAdapter(arrayAdapter);
}
}
}
}
这里是ListFragments代码：
package com.thesis.menubook;
import android.annotation.TargetApi;
import android.app.ListFragment;
import android.os.Build;
import android.os.Bundle;
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class MenuCategory extends ListFragment {
@Override
public void onActivityCreated(Bundle savedState) {
super.onActivityCreated(savedState);
}
}
这是ListFragments XML：
<?xml version="1.0" encoding="utf-8"?>
<ListView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</ListView>
如果有帮助，这里是LogCat：
02-13 22:57:35.422: V/TLINE(1349): new: android.text.TextLine@4066c0c0
02-13 22:57:36.702: V/TLINE(1349): new: android.text.TextLine@40674c00
02-13 22:57:59.142: D/dalvikvm(1349): GC_FOR_ALLOC freed 161K, 5% free 6481K/6791K, paused 162ms
02-13 22:57:59.184: I/dalvikvm-heap(1349): Grow heap (frag case) to 6.926MB for 513744-byte allocation
02-13 22:57:59.562: D/dalvikvm(1349): GC_CONCURRENT freed 13K, 5% free 6969K/7303K, paused 50ms+26ms
02-13 22:58:02.334: D/NetWork Info(1349): NetworkInfo: type: mobile[UMTS], state: CONNECTED/CONNECTED, reason: simLoaded, extra: internet, roaming: false, failover: false, isAvailable: true
02-13 22:58:08.841: D/Response(1349): org.apache.http.message.BasicHttpResponse@406867f8--response from apache
02-13 22:58:08.841: D/IP Address(1349): 192.168.10.149:80
02-13 22:58:09.181: D/NEXT VALUE --in Async on postexecute(1349): true
02-13 22:58:18.232: D/dalvikvm(1349): GC_CONCURRENT freed 139K, 4% free 7258K/7559K, paused 40ms+13ms
02-13 22:58:18.802: D/URL(1349): http://192.168.10.149:80/MenuBook/checkTable.php
02-13 22:58:23.082: D/Check Table(1349): {"success":1,"tabledb":[{"table_location":"UP","table_seat":"5","table_status":"AVAILABLE","table_ID":"001"}]}
02-13 22:58:23.082: D/Table Status in doinbg(1349): AVAILABLE
02-13 22:58:23.192: D/Table Status in post execute(1349): AVAILABLE
02-13 22:58:25.622: D/IP ADDRESS(1349): 192.168.10.149:80
02-13 22:58:28.432: D/dalvikvm(1349): GC_CONCURRENT freed 353K, 7% free 7356K/7879K, paused 14ms+264ms
02-13 22:58:32.556: D/All Categories:(1349): {"success":1,"category_list":[{"category":"MAIN DISH"},{"category":"MAIN DISH"},{"category":"DESSERT"}]}
02-13 22:58:33.273: D/Category List JSON Array(1349): [{"category":"MAIN DISH"},{"category":"MAIN DISH"},{"category":"DESSERT"}]
02-13 22:58:33.852: D/category #1(1349): MAIN DISH
02-13 22:58:34.982: D/Category List(1349): [{category=MAIN DISH}]
02-13 22:58:35.164: D/category #2(1349): DESSERT
02-13 22:58:35.382: D/Category List(1349): [{category=MAIN DISH}, {category=DESSERT}]
02-13 22:58:35.664: D/Category List(1349): [{category=MAIN DISH}, {category=DESSERT}]