我正在尝试使用JSONObject并在listview中显示。该对象的请求返回了它应该返回的内容,似乎其余的代码都无法正常工作...。
这是我的代码:
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:
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"}]}
如您所见,JSON信息已被提取,只是从那里做的不多。在应用程序本身上,屏幕只是空白,没有列表视图或没有填充列表视图。
最佳答案
AsyncTask在BackGround中执行,因此直到填充directlyList
之前,您一直将其设置为listAdapter,填充setListAdapter
之后需要directoryList
您必须像这样在setListAdapter
中onPostExecute
->
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);
}