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我有一個ListView和一個列表視圖適配器。適配器從List填充ListView。列表視圖有一個onScrollListener。我遇到的問題是當滾動新數據加載到視圖，但滾動條跳轉到視圖的頂部。Android Listview Scroll position
我想要的是保持滾動位置在哪裏！
任何幫助？ 感謝
列表視圖類：
private class GetItems extends AsyncTask<Void, Void, Void>
{
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(AppList.this);
// Set progressdialog title
mProgressDialog.setTitle("Loading more");
mProgressDialog.setMessage("loading);
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params)
{
applicationList = new ArrayList();
try
{
GetDataAppList getDataAppList = new GetDataAppList();
JSONArray jsonData = getDataAppList.getJSONData(webfileName, limit, offset);
for (int i = 0; i <= jsonData.length() - 2; i++)
{
JSONObject c = jsonData.getJSONObject(i);
id = c.getString("id");
name = c.getString("name");
logo = c.getString("logo");
developer = c.getString("developer");
rate = c.getInt("rates");
category = c.getInt("category");
fileName = c.getString("filename");
path = c.getString("path");
appSize = c.getDouble("size");
if(category == 1001)
{
String gCat = c.getString("game_category");
applicationList.add(new ApplicationPojo(id,name,logo,developer,appSize,category,fileName,path,gCat));
}
else
{
applicationList.add(new ApplicationPojo(id,name,logo,developer,appSize,category,fileName,path));
}
}
JSONObject sizeObj = jsonData.getJSONObject(jsonData.length() - 1);
size = sizeObj.getInt("size");
}
catch (Exception ex)
{
Log.d("Thread:", ex.toString());
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
// Locate the ListView in listview.xml
listview = (ListView) findViewById(R.id.listView);
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapter(AppList.this, applicationList,listview);
// Binds the Adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
// Create an OnScrollListener
listview.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
int threshold = 1;
int count = listview.getCount();
if (scrollState == SCROLL_STATE_IDLE) {
if (listview.getLastVisiblePosition() >= count - threshold) {
if (size >= offset)
{
new LoadMoreDataTask().execute();
offset = offset + 15;
}
else
{
Toast.makeText(getApplicationContext(), "ختم لست!", Toast.LENGTH_LONG).show();
}
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
}
});
RatingBar bar = (RatingBar) findViewById(R.id.ratingBarShow);
}
}
private class LoadMoreDataTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(AppList.this);
mProgressDialog.setTitle("Loading more");
mProgressDialog.setMessage("loading);
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params)
{
try
{
GetDataAppList getDataAppList = new GetDataAppList();
JSONArray jsonData = getDataAppList.getJSONData(webfileName, limit, offset);
for (int i = 0; i <= jsonData.length(); i++) {
JSONObject c = jsonData.getJSONObject(i);
id = c.getString("id");
name = c.getString("name");
logo = c.getString("logo");
developer = c.getString("developer");
rate = c.getInt("rates");
category = c.getInt("category");
fileName = c.getString("filename");
path = c.getString("path");
appSize = c.getDouble("size");
if(category == 1001)
{
String gCat = c.getString("game_category");
applicationList.add(new ApplicationPojo(id,name,logo,developer,appSize,category,fileName,path,gCat));
}
else
{
applicationList.add(new ApplicationPojo(id,name,logo,developer,appSize,category,fileName,path));
}
}
}
catch (Exception ex)
{
}
return null;
}
@Override
protected void onPostExecute(Void result)
{
int position = listview.getLastVisiblePosition();
adapter = new ListViewAdapter(AppList.this, applicationList,listview);
listview.setAdapter(adapter);
listview.setSelectionFromTop(position, 0);
mProgressDialog.dismiss();
}
}
的Adpater類：列表視圖的
public ListViewAdapter(Activity activity, ArrayList<ApplicationPojo> applicationList, ListView listView)
{
this.activity = activity;
this.applicationList = applicationList;
this.inflater = LayoutInflater.from(activity);
downloader = new ApkFileDownloader(activity);
this.listView = listView;
}
@Override
public int getCount() {
return applicationList.size();
}
@Override
public ApplicationPojo getItem(int position) {
return applicationList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
public View getView(final int position, View view, ViewGroup parent)
{
if (view == null)
{
holder = new ViewHolder();
view = inflater.inflate(R.layout.singleapp, null);
holder.openInstalledAppBtn = (ImageView) view.findViewById(R.id.openInstalledApp);
holder.downloadBtn = (ImageView) view.findViewById(R.id.updateApp);
holder.progressBar = (ProgressBar)view.findViewById(R.id.updateProgress);
holder.cancelBtn = (ImageView) view.findViewById(R.id.cancel);
holder.appName = (TextView) view.findViewById(R.id.appName);
holder.developer = (TextView) view.findViewById(R.id.developer);
holder.size = (TextView) view.findViewById(R.id.size);
holder.appCat = (TextView) view.findViewById((R.id.appCat));
holder.installBtn = (ImageView) view.findViewById(R.id.install);
holder.catlogo = (ImageView) view.findViewById(R.id.catlogo);
view.setTag(holder);
}
else
{
holder = (ViewHolder) view.getTag();
}
try
{
final View finalView = view;
holder.logo = (ImageView) finalView.findViewById(R.id.appLogo);
logoName = applicationList.get(position).getLogo();
Picasso.with(activity)
.load(IPClass.SERVERIP + logoName)
.into(holder.logo);
// holder.logo.setOnClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View arg0) {
//
// }
// });
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String appid = applicationList.get(position).getId();
int category = applicationList.get(position).getCategory();
Intent rec1Intent = new Intent(activity, AppView.class);
activity.startActivity(rec1Intent);
AppView appView = new AppView();
appView.setParameters(appid, category);
AppList.adapter.notifyDataSetChanged();
}
});
final String id = applicationList.get(position).getId();
final String path = applicationList.get(position).getPath();
final String fileName = applicationList.get(position).getFileName();
final String name = applicationList.get(position).getName();
final String developer = applicationList.get(position).getDeveloper();
final double size = applicationList.get(position).getSize();
final String logo = applicationList.get(position).getLogo();
final int category = applicationList.get(position).getCategory();
final String appName = applicationList.get(position).getFileName();
String checkAppInstalled = appName.substring(0,appName.length() - 4);
//------------CHECK IF APPLICATION IS INSTALLED ----------------------------------------
if(appInstalled(checkAppInstalled))
{
holder.downloadBtn.setVisibility(View.GONE);
holder.cancelBtn.setVisibility(View.GONE);
holder.progressBar.setVisibility(View.GONE);
holder.installBtn.setVisibility(View.GONE);
holder.openInstalledAppBtn.setVisibility(View.VISIBLE);
holder.openInstalledAppBtn.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
String fileName = (applicationList.get(position).getFileName());
String appToOpen = fileName.substring(0,fileName.length() - 4);
Context ctx = activity.getApplicationContext();
Intent mIntent = ctx.getPackageManager().getLaunchIntentForPackage(appToOpen);
String mainActivity = mIntent.getComponent().getClassName();
Intent intent = new Intent("android.intent.category.LAUNCHER");
intent.setClassName(appToOpen, mainActivity);
activity.startActivity(intent);
}
});
}
//------------- IF APPLICATION IS NOT ALREADY INSTALLED --------------------------------
else
{
//------------------------ CHECK IF APK EXISTS -------------------------------------
String filePath = Environment.getExternalStorageDirectory().toString();
File file = new File(filePath + "/appsaraai/" + fileName);
if(file.exists())
{
holder.downloadBtn.setVisibility(View.GONE);
holder.cancelBtn.setVisibility(View.GONE);
holder.openInstalledAppBtn.setVisibility(View.GONE);
holder.progressBar.setVisibility(View.GONE);
holder.installBtn.setVisibility(View.VISIBLE);
holder.installBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(new File(Environment.getExternalStorageDirectory() + "/appsaraai/" + fileName)), "application/vnd.android.package-archive");
activity.startActivity(intent);
for (int i = 0; i < DownloadLists.list.size(); i++) {
if (DownloadLists.list.get(i).getName().equals(name)) {
DownloadLists.list.remove(i);
}
}
}
});
AppList.adapter.notifyDataSetChanged();
}
//------------------ IF APK DOES NOT EXIST -----------------------------------------
else
{
//-----CHECK IF DOWNLOAD IS IN PROGRESS ----------------------------------------
if (ApkFileDownloader.applicationList.containsKey(name))
{
holder.downloadBtn.setVisibility(View.GONE);
holder.installBtn.setVisibility(View.GONE);
holder.openInstalledAppBtn.setVisibility(View.GONE);
new ApkFileDownloader(activity).getDownloadStatus(holder.progressBar, name, holder.installBtn, holder.cancelBtn);
holder.progressBar.setVisibility(View.VISIBLE);
holder.cancelBtn.setVisibility(View.VISIBLE);
holder.cancelBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
downloader.cancelDownload(name);
holder.cancelBtn.setVisibility(View.GONE);
holder.downloadBtn.setVisibility(View.VISIBLE);
DownloadLists dlist = new DownloadLists(activity);
dlist.deleteData(name);
try {
AppList.adapter.notifyDataSetChanged();
} catch (Exception ex) {
System.out.println(ex);
}
try
{
SearchResult.adapter.notifyDataSetChanged();
}
catch (Exception ex)
{
System.out.println(ex);
}
}
});
}
//-------------- IF DOWNLOAD IS NOT IN PROGRESS START NEW DOWNLOAD -------------
else
{
holder.progressBar.setVisibility(View.GONE);
holder.cancelBtn.setVisibility(View.GONE);
holder.installBtn.setVisibility(View.GONE);
holder.openInstalledAppBtn.setVisibility(View.GONE);
holder.downloadBtn.setVisibility(view.VISIBLE);
holder.downloadBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
holder.downloadBtn.setVisibility(View.GONE);
holder.cancelBtn.setVisibility(View.VISIBLE);
holder.cancelBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
downloader.cancelDownload(name);
holder.cancelBtn.setVisibility(View.GONE);
holder.downloadBtn.setVisibility(View.VISIBLE);
try {
AppList.adapter.notifyDataSetChanged();
} catch (Exception ex) {
System.out.println(ex);
}
try {
SearchResult.adapter.notifyDataSetChanged();
} catch (Exception ex) {
System.out.println(ex);
}
}
});
new Thread(new Runnable() {
@Override
public void run() {
try {
Bitmap logoImg = Picasso.with(activity).load(IPClass.SERVERIP + logo).get();
DownloadLists.list.add(new ApplicationPojo(id, name, developer, size, logoImg, holder.progressBar));
DownloadLists dlist = new DownloadLists(activity);
dlist.insertData(id, name, developer, size, fileName, logoImg);
UpdateServerDownload d = new UpdateServerDownload();
d.updateDownloadNo(id, category);
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
new ApkFileDownloader(activity).setParameters(path, fileName, name);
try {
AppList.adapter.notifyDataSetChanged();
} catch (Exception ex) {
System.out.println(ex);
}
try {
SearchResult.adapter.notifyDataSetChanged();
} catch (Exception ex) {
System.out.println(ex);
}
}
});
}
}
}
holder.appName.setText(applicationList.get(position).getName());
holder.developer.setText(applicationList.get(position).getDeveloper());
String sizeText = " میگابایت ";
String appSize =String.valueOf(applicationList.get(position).getSize()) + sizeText;
holder.size.setText(appSize);
if(category == 1001)
{
String cat = applicationList.get(position).getgCat();
holder.appCat.setText(" " + returnGameCat(cat));
holder.catlogo.setImageResource(R.drawable.gamecatlogo);
}
}
catch (Exception ex)
{
Log.d("Adapter Exception", ex.toString());
}
return view;
}
//--------------- A METHOD TO CHECK IF APPLICATION IS ALREADY INSTALLED ------------------------
public boolean appInstalled(String checkApp)
{
pm = activity.getPackageManager();
try
{
pm.getPackageInfo(checkApp, PackageManager.GET_ACTIVITIES);
isAppInstalled = true;
}
catch (PackageManager.NameNotFoundException e)
{
isAppInstalled = false;
}
return isAppInstalled;
}
顯示你的代碼。 – Rajesh
這個問題有許多最佳解決方案，但標準只是將您的新數據添加到原始列表並通知適配器，而不是在每個新數據請求上分配新適配器。 –