我使用PagerSlidingTabStrip库，但这个库有问题。我有一个 GridView，当页面更改时，它会通过 AsyncTask 从 Web 更新。if swipe from page 1 to page 2, page 2 get update from web but My problem is, when such as tab 1 is selected click on tab 2, page 2 not update and show page 1 content(grid adapter updated but pager not show new内容）。滑动更新内容，但选项卡选择不更新内容。我的代码有什么问题？
如何避免在寻呼机中缓存下一页和上一页？我想在选择任何页面时从服务器接收数据。
public class SubCategoryActivity extends SherlockFragmentActivity {
boolean firstPagerAdapterConfirmed = false;
LayoutInflater inflator;
PagerSlidingTabStrip tabs;
ViewPager pager;
MyPagerAdapter pagerAdapter;
TextView tvCustomTitle;
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
JSONArray jsonArray;
String[][] SubCat;
GridviewAdapter gridAdapter;
GridView gridViewSubCategory;
HashMap<String, String> map;
ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
Intent intent;
int recordNum = 0;
int totalItems = 0;
int pageNum = 1;
int itemsPerPage = 20;
boolean loadingMore = false;
int itemId[];
ProgressBar progressBar;
RelativeLayout relativeLayoutLoadingMore;
private class getSubCategoryObjects extends AsyncTask<String, Void, String> {
int i = 0;
@Override
protected String doInBackground(String... url) {
// TODO Auto-generated method stub
return BaseActivity.jsonParser.makeHttpRequest(url[0], "POST",
nameValuePairs);
}
@Override
protected void onProgressUpdate(Void... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
// progressBar.setVisibility(View.VISIBLE);
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
try {
jsonArray = new JSONArray(result);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (pageNum == 1 ) {
i = 3;
try {
recordNum = jsonArray.getJSONObject(0).getInt("recordNum");
totalItems = jsonArray.getJSONObject(1)
.getInt("totalItems");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
itemId = new int[totalItems];
for (int i = 0; i < totalItems; i++) {
try {
itemId[i] = jsonArray.getJSONObject(2).getInt(
String.valueOf(i));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
for (; i < jsonArray.length(); i++) {
JSONObject jsonObjet;
map = new HashMap<String, String>();
try {
jsonObjet = jsonArray.getJSONObject(i);
map.put("id", String.valueOf(jsonObjet.getInt("id")));
map.put("title", jsonObjet.getString("title_fa"));
map.put("image", jsonObjet.getString("image"));
map.put("price", jsonObjet.getString("price"));
map.put("date", jsonObjet.getString("date"));
list.add(map);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
if (pageNum == 1 && firstPagerAdapterConfirmed == false) {
// progressBar.setVisibility(View.GONE);
gridAdapter = new GridviewAdapter(SubCategoryActivity.this,
list);
pagerAdapter = new MyPagerAdapter(gridAdapter);
pager.setAdapter(pagerAdapter);
firstPagerAdapterConfirmed = true;
//pager.setOffscreenPageLimit(1);
}else if(pageNum == 1 && firstPagerAdapterConfirmed) {
//progressBar.setVisibility(View.GONE);
gridAdapter = new GridviewAdapter(SubCategoryActivity.this,
list);
gridViewSubCategory.setAdapter(gridAdapter);
}else {
gridAdapter.GridviewAdapterAdd(SubCategoryActivity.this,
list);
runOnUiThread(returnRes);
}
}
}
private class getSubCategory extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... url) {
// TODO Auto-generated method stub
return BaseActivity.jsonParser.makeHttpRequest(url[0], "POST",
nameValuePairs);
}
@Override
protected void onProgressUpdate(Void... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
try {
jsonArray = new JSONArray(result);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SubCat = new String[jsonArray.length()][2];
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObjet;
try {
jsonObjet = jsonArray.getJSONObject(i);
SubCat[i][0] = String.valueOf(jsonObjet.getInt("id"));
SubCat[i][1] = jsonObjet.getString("title_fa");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO: handle exception
e.toString();
}
}
pagerAdapter = new MyPagerAdapter();
pager.setAdapter(pagerAdapter);
// pager.setCurrentItem(SubCat.length-1);
// final int pageMargin = (int) TypedValue.applyDimension(
// TypedValue.COMPLEX_UNIT_DIP, 30, getResources()
// .getDisplayMetrics());
// pager.setPageMargin(pageMargin);
// pager.setCurrentItem(0);
// pager.setOffscreenPageLimit(0);
tabs.setViewPager(pager);
tabs.setTextSize(20);
tabs.setTypeface(BaseActivity.font, Typeface.NORMAL);
list = new ArrayList<HashMap<String, String>>();
nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("getAdvertise", "true"));
nameValuePairs
.add(new BasicNameValuePair("subCatId", SubCat[0][0]));
new getSubCategoryObjects().execute(url2);
}
}
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
intent = getIntent();
tabs = (PagerSlidingTabStrip) findViewById(R.id.tabs);
pager = (ViewPager) findViewById(R.id.pager);
tabs.setOnPageChangeListener(new OnPageChangeListener() {
@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
recordNum = 0;
totalItems = 0;
pageNum = 1;
//loadingMore = false;
jsonArray = new JSONArray();
list = new ArrayList<HashMap<String, String>>();
nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("getAdvertise",
"true"));
nameValuePairs.add(new BasicNameValuePair("subCatId",
SubCat[arg0][0]));
// Activity myActivity = getActivity();
// if (myActivity instanceof SubCategoryActivity) {
new getSubCategoryObjects().execute(url2);
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub
}
@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub
}
});
inflator = SubCategoryActivity.this.getLayoutInflater();
jsonArray = new JSONArray();
nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("getSubCategory", "true"));
nameValuePairs.add(new BasicNameValuePair("catId", intent
.getStringExtra("id")));
new getSubCategory().execute(url);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayShowCustomEnabled(true);
tvCustomTitle = new TextView(this);
tvCustomTitle.setText(intent.getStringExtra("title"));
LinearLayout ll = new LinearLayout(this);
LinearLayout.LayoutParams para = new LinearLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
para.setMargins(0, 0, 0, 0); // left,top,right, bottom
para.gravity = Gravity.CENTER_VERTICAL;
tvCustomTitle.setTypeface(BaseActivity.font);
Configuration config = getResources().getConfiguration();
if (Build.VERSION.SDK_INT >= 13) {
if (config.smallestScreenWidthDp >= 600) {
tvCustomTitle.setTextSize(22);
} else {
tvCustomTitle.setTextSize(14);
}
} else {
tvCustomTitle.setTextSize(14);
}
tvCustomTitle.setTextColor(Color.WHITE);
ll.addView(tvCustomTitle, para);
getSupportActionBar().setCustomView(ll);
changeColor(intent.getIntExtra("color", Color.parseColor("#FF666666")));
}
private void changeColor(int newColor) {
tabs.setIndicatorColor(newColor);
// change ActionBar color just if an ActionBar is available
Drawable colorDrawable = new ColorDrawable(newColor);
Drawable bottomDrawable = getResources().getDrawable(
R.drawable.actionbar_bottom);
LayerDrawable ld = new LayerDrawable(new Drawable[] { colorDrawable,
bottomDrawable });
getSupportActionBar().setBackgroundDrawable(ld);
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
public class MyPagerAdapter extends PagerAdapter {
GridviewAdapter gridAdapter;
public MyPagerAdapter(GridviewAdapter gridAdapter) {
// TODO Auto-generated constructor stub
this.gridAdapter = gridAdapter;
}
public MyPagerAdapter() {
// TODO Auto-generated constructor stub
}
public Object instantiateItem(View collection, int position) {
View rootView = inflator.inflate(
R.layout.fragment_sub_category_objects, null);
gridViewSubCategory = (GridView) rootView
.findViewById(R.id.gridViewSubCategory);
//progressBar = (ProgressBar) rootView.findViewById(R.id.progressBar);
relativeLayoutLoadingMore = (RelativeLayout) rootView.findViewById(R.id.relativeLayoutLoadingMore);
gridViewSubCategory.setAdapter(gridAdapter);
gridViewSubCategory
.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,
View view, int position, long id) {
// TODO Auto-generated method stub
BaseActivity.cd = new ConnectionDetector(
SubCategoryActivity.this);
BaseActivity.isInternetPresent = BaseActivity.cd
.isConnectingToInternet();
if (BaseActivity.isInternetPresent) {
Intent i = new Intent(SubCategoryActivity.this,
SubCategoryActivity.class);
i.putExtra("id", ((TextView) view
.findViewById(R.id.textViewId))
.getText().toString());
i.putExtra(
"color",
i.getIntExtra("color",
Color.parseColor("#FF666666")));
startActivity(i);
} else {
Toast.makeText(
SubCategoryActivity.this,
"به اینترنت متصل نیستید، به اینترنت متصل شده و دوباره امتحان کنید.",
Toast.LENGTH_SHORT).show();
}
}
});
gridViewSubCategory.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view,
int scrollState) {
// TODO Auto-generated method stub
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
// save index and top position
// what is the bottom iten that is visible
int lastInScreen = firstVisibleItem + visibleItemCount;
// is the bottom item visible & not loading more already ?
// Load
// more !
if ((lastInScreen == totalItemCount) && !(loadingMore)
&& recordNum > 1) {
recordNum--;
pageNum++;
relativeLayoutLoadingMore.setVisibility(View.VISIBLE);
Thread thread = new Thread(null, loadMoreGridItems);
thread.start();
}
}
});
((ViewPager) collection).addView(rootView, 0);
return rootView;
}
@Override
public CharSequence getPageTitle(int position) {
return SubCat[position][1];
}
@Override
public int getCount() {
return SubCat.length;
}
@Override
public void destroyItem(View collection, int position, Object view) {
((ViewPager)collection).removeView((RelativeLayout) view);
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((RelativeLayout) object);
}
}
// Runnable to load the items
private Runnable loadMoreGridItems = new Runnable() {
@Override
public void run() {
// Set flag so we cant load new items 2 at the same time
loadingMore = true;
// Reset the array that holds the new items
list = new ArrayList<HashMap<String, String>>();
nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("getAdvertise", "true"));
nameValuePairs
.add(new BasicNameValuePair("subCatId", SubCat[pager.getCurrentItem()][0]));
nameValuePairs.add(new BasicNameValuePair("pageNum", String
.valueOf(pageNum)));
new getSubCategoryObjects().execute(url3);
}
};
// Since we cant update our UI from a thread this Runnable takes care of
// that!
private Runnable returnRes = new Runnable() {
@Override
public void run() {
//pager.requestLayout();
relativeLayoutLoadingMore.setVisibility(View.GONE);
gridViewSubCategory.setAdapter(gridAdapter);
//gridAdapter.notifyDataSetChanged();
// Done loading more.
loadingMore = false;
}
};
public class GridviewAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> list;
HashMap<String, String> tempMap;
public GridviewAdapter(Activity activity,
ArrayList<HashMap<String, String>> list) {
this.activity = activity;
this.list = list;
}
public void GridviewAdapterAdd(Activity activity,
ArrayList<HashMap<String, String>> list) {
this.activity = activity;
for (int i = 0; i < list.size(); i++)
this.list.add(list.get(i));
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
LayoutInflater inflator = activity.getLayoutInflater();
View vi = convertView;
if (convertView == null)
vi = inflator.inflate(R.layout.gridview_sub_category_row, null);
TextView id = (TextView) vi.findViewById(R.id.textViewId);
TextView title = (TextView) vi.findViewById(R.id.textViewTitle);
ImageView imageViewSubCat = (ImageView) vi
.findViewById(R.id.imageViewSubCat);
TextView price = (TextView) vi.findViewById(R.id.textViewPrice);
TextView date = (TextView) vi.findViewById(R.id.textViewDate);
RelativeLayout textBackground = (RelativeLayout) vi
.findViewById(R.id.relativeLayoutText);
tempMap = new HashMap<String, String>();
tempMap = list.get(position);
id.setText(tempMap.get("id"));
textBackground.setBackgroundColor(intent.getIntExtra("color",
Color.parseColor("#FF666666")));
title.setText(tempMap.get("title"));
price.setText(tempMap.get("price"));
date.setText(tempMap.get("date"));
title.setTypeface(BaseActivity.font);
price.setTypeface(BaseActivity.font);
date.setTypeface(BaseActivity.font);
// File cachedImg = ImageLoader.getInstance().getDiscCache()
// .get(picUrl + tempMap.get("logo") + ".jpg");
// if (cachedImg.exists())
// cachedImg.delete();
ImageLoader.getInstance().displayImage(
BaseActivity.picUrl + tempMap.get("image") + ".jpg",
imageViewSubCat);
return vi;
}
}