问题
I am converting my HTTP calls to asynchronous calls from synchronous ones. Because the connection is running in the background the data isn't there when I originally set my list adaptor. How can I get the list adaptor to update after my HTTP call? I've tried a few things like not setting the adaptor until data gets sent back and setting the adaptor again, but nothing has worked. Here's my current oncreate code
protected void onCreate(Bundle savedInstanceState) {
overridePendingTransition(R.layout.anim_out,R.layout.anim_in);
setTheme(R.style.Theme_D_theme);
setContentView(R.layout.news_fragment);
super.onCreate(savedInstanceState);
text = (TextView) this.findViewById(R.id.nomore);
list = (ListView) this.findViewById(R.id.newslist);
list.setDividerHeight(2);
new MyAsyncTask().execute("THIS");
list.setOnItemClickListener(this);
list.setCacheColorHint(Color.WHITE);
adapter = new SimpleAdapter(this, x, R.layout.drill1_listview,
new String[] {"title","content","distance", "image"},
new int[] {R.id.title, R.id.content, R.id.distance, R.id.image} );
}
And my AsyncTast
private class MyAsyncTask extends AsyncTask<String, Integer, Double>{
@Override
protected Double doInBackground(String... params) {
// TODO Auto-generated method stub
postData(params[0]);
return null;
}
protected void onPostExecute(Double result){
//pb.setVisibility(View.GONE);
Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
}
protected void onProgressUpdate(Integer... progress){
//pb.setProgress(progress[0]);
}
public void postData(String valueIWantToSend) {
ThreadPolicy tp = ThreadPolicy.LAX;
StrictMode.setThreadPolicy(tp);
HttpClient httpclient = new DefaultHttpClient();
String type = getIntent().getExtras().getString("type");
HttpGet httppost = new HttpGet("http://myip.../all?latitude=42.12345&longitude=-76.2154");
InputStream inputStream = null;
try {
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
String JSONstring = EntityUtils.toString(entity);
Log.w("HTTPRESPONSE", JSONstring);
//Toast.makeText(this, JSONstring, Toast.LENGTH_SHORT).show();
if (!(JSONstring.equals(" 0"))) {
JSONArray array = new JSONArray(JSONstring);
for (int i = 0; i < array.length(); i++) {
JSONObject row = array.getJSONObject(i);
HashMap<String,String> temp = new HashMap<String,String>();
String thisid = row.getString("id");
ider.add(thisid);
String starthold = row.getString("start_time");
start.add(starthold);
String endhold = row.getString("end_time");
end.add(endhold);
String latitudehold = row.getString("latitude");
latitude.add(latitudehold);
String longitudehold = row.getString("longitude");
longitude.add(longitudehold);
String addresshold = row.getString("street");
address.add(addresshold);
String title = row.getString("company");
company.add(title);
temp.put("title", title);
String distance_hold = row.getString("distance");
distance.add(distance_hold);
temp.put("distance", distance_hold);
int[] images = new int[] { R.drawable.local_eat,R.drawable.local_eat,
R.drawable.local_drink, R.drawable.local_shop,
R.drawable.local_do, R.drawable.local_chance,
R.drawable.local_all };
String image = row.getString("promo_type");
temp.put("image", Integer.toString(images[Integer.valueOf(image)]));
String description = row.getString("name");
name.add(description);
temp.put("content", description);
x.add(temp);
}
}
} catch (Exception e) {
// Oops
} finally {
try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
}
}
}
回答1:
in on post execution add this line. in the end.
x.add(temp);
adapter.notifyDataSetChanged();
回答2:
Do this way
private class MyAsyncTask extends AsyncTask<String, Integer, Double>{
@Override
protected Double doInBackground(String... params) {
// TODO Auto-generated method stub
postData(params[0]);
return null;
}
protected void onPostExecute(Double result){
//pb.setVisibility(View.GONE);
Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
//UPDATE HERE
adapter = new SimpleAdapter(this, x, R.layout.drill1_listview,
new String[] {"title","content","distance", "image"},
new int[] {R.id.title, R.id.content, R.id.distance, R.id.image} );
list.setAdapter(adapter);
}
protected void onProgressUpdate(Integer... progress){
//pb.setProgress(progress[0]);
}
public void postData(String valueIWantToSend) {
ThreadPolicy tp = ThreadPolicy.LAX;
StrictMode.setThreadPolicy(tp);
HttpClient httpclient = new DefaultHttpClient();
String type = getIntent().getExtras().getString("type");
HttpGet httppost = new HttpGet("http://myip.../all?latitude=42.12345&longitude=-76.2154");
InputStream inputStream = null;
try {
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
String JSONstring = EntityUtils.toString(entity);
Log.w("HTTPRESPONSE", JSONstring);
//Toast.makeText(this, JSONstring, Toast.LENGTH_SHORT).show();
if (!(JSONstring.equals(" 0"))) {
JSONArray array = new JSONArray(JSONstring);
for (int i = 0; i < array.length(); i++) {
JSONObject row = array.getJSONObject(i);
HashMap<String,String> temp = new HashMap<String,String>();
String thisid = row.getString("id");
ider.add(thisid);
String starthold = row.getString("start_time");
start.add(starthold);
String endhold = row.getString("end_time");
end.add(endhold);
String latitudehold = row.getString("latitude");
latitude.add(latitudehold);
String longitudehold = row.getString("longitude");
longitude.add(longitudehold);
String addresshold = row.getString("street");
address.add(addresshold);
String title = row.getString("company");
company.add(title);
temp.put("title", title);
String distance_hold = row.getString("distance");
distance.add(distance_hold);
temp.put("distance", distance_hold);
int[] images = new int[] { R.drawable.local_eat,R.drawable.local_eat,
R.drawable.local_drink, R.drawable.local_shop,
R.drawable.local_do, R.drawable.local_chance,
R.drawable.local_all };
String image = row.getString("promo_type");
temp.put("image", Integer.toString(images[Integer.valueOf(image)]));
String description = row.getString("name");
name.add(description);
temp.put("content", description);
x.add(temp);
}
}
} catch (Exception e) {
// Oops
} finally {
try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
}
}
}
来源：https://stackoverflow.com/questions/19042621/update-android-listview-after-asynchronous-update