嗨，我有一个片段，它从 web 服务加载 json 类型的数据并在 gridview（自定义）中显示。在前 16 个项目（第 1 页）中，我没有问题，但是当我尝试加载页面并将项目添加到适配器时有些项目重复:(
我的代码是：
分段：
@SuppressLint("ValidFragment")
public class MainTabFragment extends Fragment {
ProductArrayAdapter adapter;
LinearLayout baseLoading;
int lastpage = 1;
int totalpages = 0;
boolean loadingMore = false;
boolean isFirstTime = true;
RelativeLayout listFooterLoading;
com.goldenapps.iran14.GridView grdProducts;
GifDecoderView view;
ImageButton imgbtnConnectionLost;
public static final String CATEGORY_VIP = "vip";
public static final String CATEGORY_EMG = "fori";
String curentCat = "";
//Banner data
LinearLayout lytBanner;
ImageView imgBanner;
int bannerId = 0;
String bannerThumbnail = "";
String bannerContent = "";
String bannerUrl = "";
String bannerBGcolor = "";
public MainTabFragment() {
bannerId = 1;
}
public MainTabFragment(String _currentCat) {
this.curentCat = _currentCat;
if(this.curentCat.equals("")){
bannerId = 1;
}else if(this.curentCat.equals(CATEGORY_EMG)){
bannerId = 2;
}else if(this.curentCat.equals(CATEGORY_VIP)){
bannerId = 3;
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
baseLoading = (LinearLayout) rootView.findViewById(R.id.baseLoading);
grdProducts = (com.goldenapps.iran14.GridView) rootView.findViewById(R.id.grdProducts);
grdProducts.setOnScrollListener(new EndlessScrollListener(0));
grdProducts.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
// TODO Auto-generated method stub
Product p = adapter.getList().get(arg2);
ArrayList<Product> arrp = new ArrayList<Product>();
arrp.add(p);
Intent intent = new Intent(getActivity(), OtherActivity.class);
Bundle b = new Bundle();
b.putParcelableArrayList("Product", arrp);
if(!p.getImageviewUrl().equals("")){
b.putString("ImageUrl", p.getImageviewUrl());
}else if(p.getImages().size() > 0){
b.putString("ImageUrl", p.getImages().get(0));
}else{
b.putString("ImageUrl", "");
}
b.putInt(OtherActivity.FRAGMENT_TYPE, OtherActivity.FRAGMENT_TYPE_PRODUCTVIEW);
intent.putExtras(b);
getActivity().startActivity(intent);
}
});
LayoutInflater inflinflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View banner = inflinflater.inflate(R.layout.layout_top_banner, null);
// String[] colors = getActivity().getResources().getStringArray(R.array.iran14_banner_colors);
// Random rand = new Random();
LinearLayout lytBanner = (LinearLayout) banner.findViewById(R.id.lytBanner);
// lytBanner.setBackgroundColor(Color.parseColor(colors[rand.nextInt(colors.length)]));
imgBanner = (ImageView) banner.findViewById(R.id.imgBanner);
grdProducts.addHeaderView(banner);
//Footer loading
listFooterLoading = (RelativeLayout) rootView.findViewById(R.id.lytLoading);
listFooterLoading.addView(Globals.getFooterLoading(getActivity()));
isStarting();
new LoadBannerDataTask(lytBanner).execute(bannerId);
return rootView;
}
/**
* Load products task
* @author Server
*
*/
private class LoadContentsAsync extends AsyncTask<Integer, Void, Boolean>{
//Dialog d;
String err = "";
//View loadingView;
ArrayList<Product> tmpProducts = new ArrayList<Product>();
@Override
protected void onPreExecute() {
super.onPreExecute();
if(lastpage <= 2){
baseLoading.setVisibility(View.VISIBLE);
}
loadingMore = true;
}
@Override
protected Boolean doInBackground(Integer... params) {
// TODO Auto-generated method stub
JSONObject responseObject = null;
String jsonText = "";
if(!curentCat.equals("")){
jsonText = JsonConnections.getCategoryItemsFromServer(curentCat, params[0], false, getActivity()).trim();
}else{
jsonText = JsonConnections.getDataFromServer(params[0],false,getActivity()).trim();
}
if(jsonText == null){
return false;
}
if(jsonText.equals("")){
return false;
}
if(!Globals.isJSON(jsonText)){
return false;
}
try{
jsonText = jsonText.replaceAll("\n", "\\n");
responseObject = new JSONObject(jsonText);
if(!responseObject.getString("status").equals("ok")){
if(responseObject.has("error")){
err = responseObject.getString("error");
}else{
err += "موردی یافت نشد";
}
return false;
}else{
if(responseObject.has("pages")){
totalpages = responseObject.getInt("pages");
}
if(responseObject.has("count")){
int c = responseObject.getInt("count");
if(c < 1){
err += "موردی یافت نشد";
return false;
}
}
}
JSONArray posts = responseObject.getJSONArray("posts");
for(int i = 0; i < posts.length() ; i++){
JSONObject obj = posts.getJSONObject(i);
Product p = new Product();
p.setId(obj.getInt("id"));
p.setTitle((String) obj.get("title"));
p.setUrl((String) obj.get("url"));
p.setDate(((String) obj.get("date")).split(" ")[0]);
p.setTime(((String) obj.get("date")).split(" ")[1]);
if(obj.has("thumbnail_images")){
JSONObject objImageView = obj.getJSONObject("thumbnail_images");
if(objImageView != null){
if(objImageView.has("url")){
p.setImageviewUrl(objImageView.getString("url"));
}
}
}
ArrayList<String> images = new ArrayList<String>();
if(obj.has("thumbnail")){
if(obj.get("thumbnail") != null){
images.add((String) obj.get("thumbnail"));
}
}
//شاخه ها
if(obj.has("categories")){
JSONArray arrCategories = obj.getJSONArray("categories");
if(arrCategories != null){
if(arrCategories.length() > 0){
for(int j=0; j<arrCategories.length(); j++){
JSONObject objCat = arrCategories.getJSONObject(j);
if(objCat.getString("slug").equals(Product.TAG_VIP)){
p.setType(Product.TYPE_VIP);
break;
}else if(objCat.getString("slug").equals(Product.TAG_FORI)){
p.setType(Product.TYPE_FORI);
break;
}
}
}
}
}
p.setImages(images);
Log.i("Product", p.getTitle() + " , type= " + p.getType());
tmpProducts.add( p );
}
return true;
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
err += "خطا در ارتباط با سرور";
}
return false;
}
protected void onPostExecute(Boolean done){
loadingMore = false;
if(lastpage <= 2){
baseLoading.setVisibility(View.GONE);
}else{
listFooterLoading.setVisibility(View.GONE);
}
if(done){
if(isFirstTime){
isFirstTime = false;
adapter = new ProductArrayAdapter(getActivity(), tmpProducts, Product.NORMAL, null);
grdProducts.setAdapter(adapter);
}else{
for(Product p : tmpProducts){
adapter.add(p);
}
}
adapter.notifyDataSetChanged();
}else{
if(err.equals("")){
Globals.showMessage(getActivity(), "خطا");
}else{
Globals.showMessage(getActivity(), err);
}
}
if(adapter != null){
if(adapter.getCount() > 0){
new DownloadImageTask(null).execute(new String[]{""});
}
}
}
}
/**
* Load products task
* @author Server
*
*/
private class DownloadImageTask extends AsyncTask<String, Integer, Bitmap> {
public DownloadImageTask(ImageView bmImage) {
}
protected Bitmap doInBackground(String... urls) {
Bitmap mIcon11 = null;
ArrayList<Product> tmplist = adapter.getList();
int min = 0;
if(tmplist.size() > 16){
min = tmplist.size()-16;
}
for(int i=min ; i < tmplist.size() ; i++) {
if(tmplist.get(i) != null){
try{
if(tmplist.get(i).getImages().size() <= 0){
continue;
}
if(tmplist.get(i).getImages().get(0).equals("")){
continue;
}
InputStream in = new java.net.URL(tmplist.get(i).getImages().get(0)).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
if(mIcon11 != null){
tmplist.get(i).setMainImage(mIcon11);
}
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
publishProgress(0);
}
}
return null;
}
protected void onPostExecute(Bitmap result) {
// bmImage.setImageBitmap(result);
}
protected void onProgressUpdate(Integer... progress){
adapter.notifyDataSetChanged();
super.onProgressUpdate(progress[0]);
}
}
private boolean isStarting(){
InputStream stream = null;
try {
stream = getActivity().getAssets().open("loading.gif");
} catch (IOException e) {
e.printStackTrace();
}
view = new GifDecoderView(getActivity(), stream);
baseLoading.removeAllViews();
baseLoading.addView(view);
if(lastpage <=1 ){
baseLoading.setVisibility(View.VISIBLE);
}else{
baseLoading.setVisibility(View.GONE);
}
if(Globals.isNetworkOnline(getActivity())){
new LoadContentsAsync().execute(lastpage++);
return true;
}else{
baseLoading.setVisibility(View.GONE);
imgbtnConnectionLost = new ImageButton(getActivity());
imgbtnConnectionLost.setImageDrawable(getActivity().getResources().getDrawable(R.drawable.connection_lost_icon));
imgbtnConnectionLost.setBackgroundColor(Color.TRANSPARENT);
baseLoading.removeAllViews();
baseLoading.addView(imgbtnConnectionLost);
baseLoading.setVisibility(View.VISIBLE);
imgbtnConnectionLost.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
isStarting();
}
});
}
return true;
}
private class EndlessScrollListener implements OnScrollListener {
private int visibleThreshold = 5;
private int previousTotal = 0;
private boolean loading = true;
public EndlessScrollListener(int visibleThreshold) {
this.visibleThreshold = visibleThreshold;
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (loading) {
if (totalItemCount > previousTotal) {
loading = false;
previousTotal = totalItemCount;
}
}
if (firstVisibleItem + visibleItemCount == totalItemCount) {
// last item in grid is on the screen, show footer:
if(lastpage <= totalpages && totalpages > 0){
listFooterLoading.setVisibility(View.VISIBLE);
}
} else if (listFooterLoading.getVisibility() != View.GONE) {
// last item in grid not on the screen, hide footer:
listFooterLoading.setVisibility(View.GONE);
}
if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) {
// I load the next page of gigs using a background task,
// but you can call any function here.
if(lastpage > totalpages && totalpages > 0){
return;
}
new LoadContentsAsync().execute(lastpage++);
loading = true;
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
}
/**
* Load products task
* @author Server
*
*/
private class LoadBannerDataTask extends AsyncTask<Integer, Void, Boolean>{
LinearLayout lytBanner;
public LoadBannerDataTask(LinearLayout _lytBanner){
this.lytBanner = _lytBanner;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Boolean doInBackground(Integer... params) {
// TODO Auto-generated method stub
JSONObject responseObject = null;
String jsonText = "";
jsonText = JsonConnections.getBannerDataFromServer(params[0], getActivity()).trim();
if(jsonText == null){
return false;
}
if(jsonText.equals("")){
return false;
}
if(!Globals.isJSON(jsonText)){
return false;
}
try{
jsonText = jsonText.replaceAll("\n", "\\n");
responseObject = new JSONObject(jsonText);
JSONArray arrBanner = responseObject.getJSONArray("banners");
JSONObject bannerObj = arrBanner.getJSONObject(0);
bannerThumbnail = bannerObj.getString("thumbnail");
bannerContent = bannerObj.getString("content");
bannerUrl = bannerObj.getString("url");
bannerBGcolor = bannerObj.getString("bgcolor");
return true;
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return false;
}
protected void onPostExecute(Boolean done){
loadingMore = false;
this.lytBanner.setBackgroundColor(Color.parseColor(bannerBGcolor));
if(bannerThumbnail != null){
if(!bannerThumbnail.equals("")){
new DownloadBannerImageTask().execute(new String[]{bannerThumbnail});
}
}
}
}
/**
* Load products task
* @author Server
*
*/
private class DownloadBannerImageTask extends AsyncTask<String, Integer, Bitmap> {
protected Bitmap doInBackground(String... urls) {
Bitmap mIcon11 = null;
try{
InputStream in = new java.net.URL(urls[0]).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
imgBanner.setImageBitmap(result);
}
}
}