JSONObject的不显示列表视图上 [英] JSONObject not displaying on Listview
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问题描述
我试图采取一个JSONObject和显示在列表视图。对象的请求返回的必要内容，似乎code的其余部分是不工作....
I'm attempting to take a JSONObject and display in listview. The request for the object is returning what it should, it seems the rest of the code isn't working....
下面是我的code：
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.NavUtils;
import android.util.JsonReader;
import android.util.Log;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class DisplayServiceActivity extends ListActivity {
private ListView listOfServices;
//JSONArrays?
JSONArray directory;
//JSON Node names
private static String TAG_ID = "id";
private static String TAG_NAME= "name";
private static String TAG_DIRECTORY = "Categories";
private final static String url= "APILINKHERE";
JSONObject json;
jsonParser jParser = new jsonParser();
ArrayList<HashMap<String, String>> directoryList;
@SuppressLint("NewApi")
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Request request = new Request();
request.execute();
listOfServices =getListView(); //get builtin listView
directoryList = new ArrayList<HashMap<String, String>>();
ListAdapter adapter = new SimpleAdapter(this,
directoryList,
R.layout.list_item,
new String[] { TAG_ID,TAG_NAME },
new int[] { android.R.id.text1,android.R.id.text2 });
setListAdapter(adapter);
setContentView(R.layout.service);
// Make sure we're running on Honeycomb or higher to use ActionBar APIs
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// Show the Up button in the action bar.
getActionBar().setDisplayHomeAsUpEnabled(true);
}
}// end of onCreate Method
@SuppressWarnings("unused")
public class Request extends AsyncTask<String, Void, JSONObject> {
private static final int REGISTRATION_TIMEOUT = 3 * 1000;
private static final int WAIT_TIMEOUT = 30 * 1000;
private ProgressDialog dialog =
new ProgressDialog(DisplayServiceActivity.this);
protected void onPreExecute() {
dialog = new ProgressDialog(DisplayServiceActivity.this);
dialog.setMessage("Getting your info real quick... Please wait...");
dialog.show();
}
protected JSONObject doInBackground(String... params) {
json = jParser.getJSONfromURL(url);
Log.e("JSON Variable", "json returns this value: " + json);
return json;
}
protected void onPostExecute(JSONObject s) {
super.onPostExecute(s);
dialog.dismiss();
Log.e("Test JSON","JSON s returns: " + s);
try {
directory = s.getJSONArray("Categories");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for(int i = 0; i< directory.length(); i++){
String str_id = directory.optString(i, "id");
String str_name = directory.optString(i, "name");
displayCatList(str_id, str_name);
Log.e("Test directory","Directory returns: " + json);
}
}
}
public void displayCatList(String id, String name){
//create new HashMap
HashMap<String,String> map = new HashMap<String, String>();
//add each child node to HashMap key
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
//adding HashList to ArrarList
directoryList.add(map);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
logcat的：
Logcat:
05-12 17:26:33.165: I/Adreno200-EGLSUB(10190): <ConfigWindowMatch:2087>: Format RGBA_8888.
05-12 17:26:34.497: E/success(10190): created object: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.497: E/JSON Variable(10190): json returns this value: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.537: E/Test JSON(10190): JSON s returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.537: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.537: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.537: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.547: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.557: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
05-12 17:26:34.557: E/Test directory(10190): Directory returns: {"Categories":[{"id":"2","name":"Glass Repair"},{"id":"3","name":"Appliance Repair"},{"id":"4","name":"Air Conditioning"},{"id":"5","name":"Community Involvement"},{"id":"6","name":"Electrical"},{"id":"7","name":"Flooring"},{"id":"8","name":"Heating Repair"},{"id":"9","name":"Landscaping"},{"id":"10","name":"Plumbing"},{"id":"11","name":"Remodeling\/Renovation"},{"id":"12","name":"Window Coverings"}]}
正如你所看到的JSON信息被牵引，它只是没有做从那里很多。在应用程序本身的屏幕，而不在ListView只是停留空白，或者被填充。
as you can see the JSON info is being pulled, it's just not doing much from there. On the app itself the screen just stays blank without the listview or it being populated.
推荐答案
的AsyncTask的执行的背景，所以直到得到填充 directlyList 的时候，你将其设置为一个listAdapter，需要 setListAdapter directoryList
The AsyncTask executes in BackGround, so till the time directlyList getting populated, you were setting it as a listAdapter, you need to setListAdapter after population of directoryList
您必须 setListAdapter 在 onPostExecute 这样的 - >
You have to setListAdapter in onPostExecute like this ->
protected void onPostExecute(JSONObject s) {
super.onPostExecute(s);
dialog.dismiss();
Log.e("Test JSON","JSON s returns: " + s);
try {
directory = s.getJSONArray("Categories");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for(int i = 0; i< directory.length(); i++){
String str_id = directory.optString(i, "id");
String str_name = directory.optString(i, "name");
displayCatList(str_id, str_name);
Log.e("Test directory","Directory returns: " + json);
}
listOfServices = DisplayServiceActivity.this.getListView(); //get builtin listView
ListAdapter adapter = new SimpleAdapter(DisplayServiceActivity.this,
directoryList,
R.layout.list_item,
new String[] { TAG_ID,TAG_NAME },
new int[] { android.R.id.text1,android.R.id.text2 });
setListAdapter(adapter);
}
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