我有一个Viewpager我在哪里加载不同类别的数据。我想，只要用户停留在一个特定的类别5秒以上，询问用户是否他/她想要分享的内容，以显示一个自定义对话框弹出。对于我已经使用了自定义对话框，我隐藏/显示基于的条件。
但问题是，如果我想，如果用户在位置保持Viewpager项，打开对话框让我们说3，对话是在第4位打开了Viewpager项目。
我不知道为什么它引用了错误的Viewpager项目。我包括适配器类的引用代码。
public class ArticleAdapter extends PagerAdapter {
public List<Articles> articlesListChild;
private LayoutInflater inflater;
Context context;
View rootView;
View customArticleShareDialog, customImageShareDialog;
public int counter = 0;
int contentType = 0;
int userId;
public ArticleAdapter(Context context, List<Articles> articlesListChild, int userId) {
super();
this.context = context;
this.userId = userId;
this.articlesListChild = articlesListChild;
}
@Override
public int getCount() {
return articlesListChild.size();
}
@Override
public void destroyItem(View collection, int position, Object view) {
((ViewPager) collection).removeView((View) view);
}
private Timer timer;
private TimerTask timerTask;
public void startTimer() {
timer = new Timer();
initializeTimerTask();
timer.schedule(timerTask, 5*1000, 5*1000);
}
private void initializeTimerTask() {
timerTask = new TimerTask() {
public void run() {
switch (contentType) {
case 1:
showShareDialog("articles");
break;
case 2:
showShareDialog("images");
break;
default :
// Do Nothing
}
}
};
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@SuppressLint("ClickableViewAccessibility")
@Override
public Object instantiateItem(ViewGroup container, final int position) {
inflater = LayoutInflater.from(container.getContext());
View viewLayout = inflater.inflate(R.layout.article_single_item, null, false);
final ImageView contentIv, imageContentIv;
final TextView sharingTextTv;
final LinearLayout articleShareBtn, articlesLayout, imagesLayout, customArticleShareDialog, customImageShareDialog;
contentIv = viewLayout.findViewById(R.id.content_iv);
articleShareBtn = viewLayout.findViewById(R.id.article_share_btn);
articlesLayout = viewLayout.findViewById(R.id.articles_layout);
imagesLayout = viewLayout.findViewById(R.id.images_layout);
imageContentIv = viewLayout.findViewById(R.id.image_content_iv);
sharingTextTv = viewLayout.findViewById(R.id.sharing_text_tv);
customArticleShareDialog = viewLayout.findViewById(R.id.articles_share_popup);
customImageShareDialog = viewLayout.findViewById(R.id.images_share_popup);
rootView = viewLayout.findViewById(R.id.post_main_cv);
viewLayout.setTag(rootView);
articleShareBtn.setTag(rootView);
// Images
if (articlesListChild.get(position).getArticleCatId() == 1) {
articlesLayout.setVisibility(GONE);
imagesLayout.setVisibility(View.VISIBLE);
RequestOptions requestOptions = new RequestOptions();
requestOptions.placeholder(R.drawable.placeholder);
Glide.with(context)
.setDefaultRequestOptions(requestOptions)
.load(articlesListChild.get(position).getArticleImage())
.into(imageContentIv);
imageContentIv.setScaleType(ImageView.ScaleType.FIT_XY);
sharingTextTv.setText("Found this image interesting? Share it with your friends.");
counter = 0;
startTimer();
// Articles
} else if (articlesListChild.get(position).getArticleCatId() == 2){
RequestOptions requestOptions = new RequestOptions();
requestOptions.placeholder(R.drawable.placeholder);
articlesLayout.setVisibility(View.VISIBLE);
Glide.with(context)
.setDefaultRequestOptions(requestOptions)
.load(articlesListChild.get(position).getArticleImage())
.into(contentIv);
contentIv.setScaleType(ImageView.ScaleType.FIT_XY);
sharingTextTv.setText("Found this article interesting? Share it with your friends.");
counter = 0;
startTimer();
}
container.addView(viewLayout, 0);
return viewLayout;
}
public void showShareDialog(String categoryType) {
if (categoryType.equalsIgnoreCase("articles")) {
new Handler(Looper.getMainLooper()).post(new Runnable() {
public void run() {
customArticleShareDialog.setVisibility(View.VISIBLE);
}
});
} else if (categoryType.equalsIgnoreCase("images")) {
new Handler(Looper.getMainLooper()).post(new Runnable() {
public void run() {
customImageShareDialog.setVisibility(View.VISIBLE);
}
});
}
}
}
public class ArticleActivity extends AppCompatActivity {
@BindView(R.id.toolbar)
Toolbar toolbar;
@BindView(R.id.drawer_layout)
DrawerLayout drawer;
@BindView(R.id.articles_view_pager)
ViewPager articlesViewPager;
@BindView(R.id.constraint_head_layout)
CoordinatorLayout constraintHeadLayout;
private ArticleAdapter articleAdapter;
private List<List<Articles>> articlesList = null;
private List<Articles> articlesListChild = new ArrayList<>();
private List<Articles> articlesListChildNew = new ArrayList<>();
SessionManager session;
Utils utils;
final static int MY_PERMISSIONS_WRITE_EXTERNAL_STORAGE = 1;
int userIdLoggedIn;
LsArticlesSharedPreference lsArticlesSharedPreference;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
ButterKnife.bind(this);
toolbar.setTitle("");
toolbar.bringToFront();
session = new SessionManager(getApplicationContext());
if (session.isLoggedIn()) {
HashMap<String, String> user = session.getUserDetails();
String userId = user.get(SessionManager.KEY_ID);
userIdLoggedIn = Integer.valueOf(userId);
} else {
userIdLoggedIn = 1000;
}
utils = new Utils(getApplicationContext());
String storedTime = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("lastUsedDate", "");
System.out.println("lastUsedDate : " + storedTime);
if (utils.isNetworkAvailable()) {
insertData();
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
toggle.getDrawerArrowDrawable().setColor(getResources().getColor(R.color.colorWhite));
drawer.addDrawerListener(toggle);
if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_WRITE_EXTERNAL_STORAGE);
}
articleAdapter = new ArticleAdapter(getApplicationContext(), articlesListChild, userIdLoggedIn);
toggle.syncState();
clickListeners();
toolbar.setVisibility(View.GONE);
} else {
Intent noInternetIntent = new Intent(getApplicationContext(), NoInternetActivity.class);
startActivity(noInternetIntent);
}
}
@Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
finishAffinity();
super.onBackPressed();
}
}
@Override
public void onStart() {
super.onStart();
}
@Override
public void onStop() {
super.onStop();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
@Override
public boolean onSupportNavigateUp() {
finish();
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_refresh:
articleAdapter.notifyDataSetChanged();
insertData();
Toast.makeText(this, "Refreshed", Toast.LENGTH_SHORT).show();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@SuppressLint("ClickableViewAccessibility")
public void clickListeners() {
}
private void insertData() {
Intent intent = new Intent(getBaseContext(), OverlayService.class);
startService(intent);
final SweetAlertDialog pDialog = new SweetAlertDialog(ArticleActivity.this, SweetAlertDialog.PROGRESS_TYPE);
pDialog.getProgressHelper().setBarColor(getResources().getColor(R.color.colorPrimary));
pDialog.setTitleText("Loading");
pDialog.setCancelable(false);
pDialog.show();
Api.getClient().getHomeScreenContents(userIdLoggedIn, new Callback<ArticlesResponse>() {
@Override
public void success(ArticlesResponse articlesResponse, Response response) {
articlesList = articlesResponse.getHomeScreenData();
if (!articlesList.isEmpty()) {
for (int i = 0; i < articlesList.size(); i++) {
articlesListChildNew = articlesList.get(i);
articlesListChild.addAll(articlesListChildNew);
}
articleAdapter = new ArticleAdapter(getApplicationContext(), articlesList, articlesListChild, userIdLoggedIn, toolbar);
articlesViewPager.setAdapter(articleAdapter);
articleAdapter.notifyDataSetChanged();
pDialog.dismiss();
} else {
List<Articles> savedArticles = lsArticlesSharedPreference.getFavorites(getApplicationContext());
if (!savedArticles.isEmpty()) {
articleAdapter = new ArticleAdapter(getApplicationContext(), articlesList, savedArticles, userIdLoggedIn, toolbar);
articlesViewPager.setAdapter(articleAdapter);
articleAdapter.notifyDataSetChanged();
pDialog.dismiss();
} else {
Api.getClient().getAllArticles(new Callback<AllArticlesResponse>() {
@Override
public void success(AllArticlesResponse allArticlesResponse, Response response) {
articlesListChild = allArticlesResponse.getArticles();
articleAdapter = new ArticleAdapter(getApplicationContext(), articlesList, articlesListChild, userIdLoggedIn, toolbar);
articlesViewPager.setAdapter(articleAdapter);
articleAdapter.notifyDataSetChanged();
};
@Override
public void failure(RetrofitError error) {
Log.e("articlesData", error.toString());
}
});
pDialog.dismiss();
}
}
}
@Override
public void failure(RetrofitError error) {
pDialog.dismiss();
Toast.makeText(ArticleActivity.this, "There was some error fetching the data.", Toast.LENGTH_SHORT).show();
}
});
}
}
问题原因：
你面对这个问题，因为在后台预加载viewpager片段。这意味着，当你看到第三个片段中，viewpager就是实例4。由于这种工作流程你的第三个屏幕计时器被取消，定时器4的屏幕开始。看看这个link明白是怎么回事。
解：
我接下来会做：
startTimer()方法实例化项目不需要调用instantiateItem()方法。