如果我在列表视图中滚动得更快，进度对话框不会关闭
Progress dialog does not dismiss if i scroll faster in my listview
如果我滚动得更快，我的 progress dialog 不会关闭并停留在屏幕上以获得无限 time.Any 帮助？尝试了很多东西，但它仍然存在。有什么办法可以消除它。我猜 dismis() 函数没有在 onPostExecute() 中调用。
代码
package com.company.napp;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.widget.AbsListView;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends Activity {
// Declare Variables
ArrayList<HashMap<String, String>> arraylist1;
int page=1;
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapter adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String TITLE = "title";
static String ADDRESS = "address";
static String COUNTRY = "country";
static String IMAGE = "image";
static String SERVICETYPE="serviceType";
static String PHNUM="phnum";
static String DESCRIPTION="description";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview_main);
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
listview = (ListView) findViewById(R.id.listview);
listview.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
int threshold = 1;
int count = listview.getCount();
System.out.println("\nLast visible = "+listview.getLastVisiblePosition()+"\nCount = "+count);
if (scrollState == SCROLL_STATE_IDLE) {
if (listview.getLastVisiblePosition()+1 > count-1) {
// Execute LoadMoreDataTask AsyncTask
new LoadMoreDataTask().execute();
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
}
//DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
mProgressDialog.setTitle("Napp");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
mProgressDialog.setCanceledOnTouchOutside(false);
//mProgressDialog.getWindow().setGravity(Gravity.BOTTOM);
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.169.88.65/events/TA/JsonTA.php?page=1");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("Contacts");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
String t, a, d, s;
t = jsonobject.getString("title");
t = t.replaceAll("\n", "");
//t="\n"+t;
a = jsonobject.getString("address");
a = a.replaceAll("\n", "");
d = jsonobject.getString("description");
d = d.replaceAll("\n", "");
s = jsonobject.getString("serviceType");
s = s.replaceAll("\n", "");
//s=s+"\n";
map.put("title", t);
map.put("address", a);
map.put("country", jsonobject.getString("country"));
map.put("image", jsonobject.getString("image"));
map.put("serviceType", s);
map.put("phnum", jsonobject.getString("phnum"));
map.put("description", d);
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
private class LoadMoreDataTask extends AsyncTask <Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
//mProgressDialog.setTitle("Napp");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
//Show progressdialog
mProgressDialog.show();
mProgressDialog.setCanceledOnTouchOutside(false);
//mProgressDialog.getWindow().setGravity(Gravity.BOTTOM);
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
page+=1;
//arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.169.88.65/events/TA/JsonTA.php?page="+page);
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("Contacts");
arraylist1 = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
String t,a,d,s;
t=jsonobject.getString("title");
t=t.replaceAll("\n", "");
//t="\n"+t;
a=jsonobject.getString("address");
a=a.replaceAll("\n","");
d=jsonobject.getString("description");
d=d.replaceAll("\n","");
s=jsonobject.getString("serviceType");
s=s.replaceAll("\n","");
//s=s+"\n";
map.put("title",t);
map.put("address",a);
map.put("country", jsonobject.getString("country"));
map.put("image", jsonobject.getString("image"));
map.put("serviceType",s);
map.put("phnum",jsonobject.getString("phnum"));
map.put("description",d);
// Set the JSON Objects into the array
arraylist1.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Set the JSON Objects into the array
arraylist.addAll(arraylist1);
//locate listview last item
int position =listview.getLastVisiblePosition();
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
//show the lastest retrieved results on the top
listview.setSelectionFromTop(position,0);
adapter.notifyDataSetChanged();
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
看起来在 Asynctask 的第一次调用完成之前，您正在再次调用它。因此，最好的解决方案是不要在每次创建任务时都创建进度对话框，而是检查对话框是否已经 运行 并进行相应处理。创建了多个进度对话框实例，但都没有被销毁
如果我滚动得更快，我的 progress dialog 不会关闭并停留在屏幕上以获得无限 time.Any 帮助？尝试了很多东西，但它仍然存在。有什么办法可以消除它。我猜 dismis() 函数没有在 onPostExecute() 中调用。
代码
package com.company.napp;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.widget.AbsListView;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class MainActivity extends Activity {
// Declare Variables
ArrayList<HashMap<String, String>> arraylist1;
int page=1;
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
ListViewAdapter adapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
static String TITLE = "title";
static String ADDRESS = "address";
static String COUNTRY = "country";
static String IMAGE = "image";
static String SERVICETYPE="serviceType";
static String PHNUM="phnum";
static String DESCRIPTION="description";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview_main);
// Execute DownloadJSON AsyncTask
new DownloadJSON().execute();
listview = (ListView) findViewById(R.id.listview);
listview.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
int threshold = 1;
int count = listview.getCount();
System.out.println("\nLast visible = "+listview.getLastVisiblePosition()+"\nCount = "+count);
if (scrollState == SCROLL_STATE_IDLE) {
if (listview.getLastVisiblePosition()+1 > count-1) {
// Execute LoadMoreDataTask AsyncTask
new LoadMoreDataTask().execute();
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
}
//DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
mProgressDialog.setTitle("Napp");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
mProgressDialog.setCanceledOnTouchOutside(false);
//mProgressDialog.getWindow().setGravity(Gravity.BOTTOM);
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.169.88.65/events/TA/JsonTA.php?page=1");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("Contacts");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
String t, a, d, s;
t = jsonobject.getString("title");
t = t.replaceAll("\n", "");
//t="\n"+t;
a = jsonobject.getString("address");
a = a.replaceAll("\n", "");
d = jsonobject.getString("description");
d = d.replaceAll("\n", "");
s = jsonobject.getString("serviceType");
s = s.replaceAll("\n", "");
//s=s+"\n";
map.put("title", t);
map.put("address", a);
map.put("country", jsonobject.getString("country"));
map.put("image", jsonobject.getString("image"));
map.put("serviceType", s);
map.put("phnum", jsonobject.getString("phnum"));
map.put("description", d);
// Set the JSON Objects into the array
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
}
}
private class LoadMoreDataTask extends AsyncTask <Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(MainActivity.this);
// Set progressdialog title
//mProgressDialog.setTitle("Napp");
// Set progressdialog message
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
//Show progressdialog
mProgressDialog.show();
mProgressDialog.setCanceledOnTouchOutside(false);
//mProgressDialog.getWindow().setGravity(Gravity.BOTTOM);
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
page+=1;
//arraylist = new ArrayList<HashMap<String, String>>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions.getJSONfromURL("http://54.169.88.65/events/TA/JsonTA.php?page="+page);
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("Contacts");
arraylist1 = new ArrayList<HashMap<String, String>>();
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
String t,a,d,s;
t=jsonobject.getString("title");
t=t.replaceAll("\n", "");
//t="\n"+t;
a=jsonobject.getString("address");
a=a.replaceAll("\n","");
d=jsonobject.getString("description");
d=d.replaceAll("\n","");
s=jsonobject.getString("serviceType");
s=s.replaceAll("\n","");
//s=s+"\n";
map.put("title",t);
map.put("address",a);
map.put("country", jsonobject.getString("country"));
map.put("image", jsonobject.getString("image"));
map.put("serviceType",s);
map.put("phnum",jsonobject.getString("phnum"));
map.put("description",d);
// Set the JSON Objects into the array
arraylist1.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Set the JSON Objects into the array
arraylist.addAll(arraylist1);
//locate listview last item
int position =listview.getLastVisiblePosition();
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
//show the lastest retrieved results on the top
listview.setSelectionFromTop(position,0);
adapter.notifyDataSetChanged();
// Close the progressdialog
mProgressDialog.dismiss();
}
}
}
看起来在 Asynctask 的第一次调用完成之前，您正在再次调用它。因此，最好的解决方案是不要在每次创建任务时都创建进度对话框，而是检查对话框是否已经 运行 并进行相应处理。创建了多个进度对话框实例，但都没有被销毁