我在我的View寻呼机中有四个标签我在谷歌搜索但是我可以找到任何解决方案当刷扫我的视图寻呼机它工作正常像1-2-3-4但当我尝试滑动反向4-3-2-1而不是我的数据丢失或你可以说我的适配器丢失。我的View Pager在Activity.My数据丢失当我转到下一页然后回来然后我的数据丢失。 我的主要活动是：
public class MainActivity extends AppCompatActivity {
public static int notificationCountCart = 0;
Toolbar toolbar;
ActionBar actionBar;
static ViewPager viewPager;
static TabLayout tabLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
if (toolbar != null)
setSupportActionBar(toolbar);
actionBar = getSupportActionBar();
if (actionBar != null) {
TextView textView = new TextView(this);
textView.setText("Shopping");
textView.setTextSize(20);
textView.setTypeface(null, Typeface.BOLD);
textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
textView.setGravity(Gravity.CENTER);
textView.setTextColor(getResources().getColor(R.color.white));
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setCustomView(textView);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeAsUpIndicator(new IconDrawable(this, FontAwesomeIcons.fa_angle_left).colorRes(R.color.white).actionBarSize());
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
viewPager = (ViewPager) findViewById(R.id.viewpagerrr);
tabLayout = (TabLayout) findViewById(R.id.tabs);
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
}
@Override
protected void onResume() {
super.onResume();
invalidateOptionsMenu();
}
@Override
public void onBackPressed() {
super.onBackPressed();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// Get the notifications MenuItem and
// its LayerDrawable (layer-list)
MenuItem item = menu.findItem(R.id.action_cart);
NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCountCart);
// force the ActionBar to relayout its MenuItems.
// onCreateOptionsMenu(Menu) will be called again.
invalidateOptionsMenu();
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_search) {
startActivity(new Intent(MainActivity.this, SearchResultActivity.class));
return true;
} else if (id == R.id.action_cart) {
/* NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCount);
invalidateOptionsMenu();*/
startActivity(new Intent(MainActivity.this, CartListActivity.class));
/* notificationCount=0;//clear notification count
invalidateOptionsMenu();*/
return true;
} else if (id == android.R.id.home) {
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
// startActivity(new Intent(MainActivity.this, EmptyActivity.class));
}
return super.onOptionsItemSelected(item);
}
private void setupViewPager(ViewPager viewPager) {
Adapter adapter = new Adapter(getSupportFragmentManager());
ImageListFragment fragment = new ImageListFragment();
SpeakerFragment speakerFragment = new SpeakerFragment();
adapter.addFragment(fragment, getString(R.string.item_2));
adapter.addFragment(speakerFragment, getString(R.string.item_4));
adapter.addFragment(new HeadPhone(), getString(R.string.item_3));
adapter.addFragment(new Offer(), getString(R.string.item_1));
viewPager.setAdapter(adapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
static class Adapter extends FragmentPagerAdapter {
private final List<Fragment> mFragments = new ArrayList<>();
private final List<String> mFragmentTitles = new ArrayList<>();
public Adapter(FragmentManager fm) {
super(fm);
}
public void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mFragmentTitles.add(title);
}
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitles.get(position);
}
}
}
我的片段是
public class ImageListFragment extends Fragment {
String category_Name, Category_ID, Product_ID, Product_Name,
Product_Image, Product_Price, Product_Sale, Cart;
public static final String STRING_IMAGE_URI = "ImageUri";
public static final String STRING_IMAGE_POSITION = "ImagePosition";
private static MainActivity mActivity;
ArrayList<SingleItemModel> singleItemModels;
RecyclerView recyclerView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getCategoryone();
Fresco.initialize(getContext());
mActivity = (MainActivity) getActivity();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
recyclerView = (RecyclerView) inflater.inflate(R.layout.layout_recylerview_list, container, false);
return recyclerView;
}
public static class SimpleStringRecyclerViewAdapter
extends RecyclerView.Adapter<ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder> {
// private String[] mValues;
private ArrayList<SingleItemModel> mValues;
private RecyclerView mRecyclerView;
public static class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final SimpleDraweeView mImageView;
public final LinearLayout mLayoutItem;
public final ImageView mImageViewWishlist;
TextView iTemName, itemDescription, itemPrice;
public ViewHolder(View view) {
super(view);
mView = view;
mImageView = (SimpleDraweeView) view.findViewById(R.id.image1);
mLayoutItem = (LinearLayout) view.findViewById(R.id.layout_item);
mImageViewWishlist = (ImageView) view.findViewById(R.id.ic_wishlist);
iTemName = (TextView) view.findViewById(R.id.itemName);
itemDescription = (TextView) view.findViewById(R.id.itemDescription);
itemPrice = (TextView) view.findViewById(R.id.itemPrice);
}
}
public SimpleStringRecyclerViewAdapter(RecyclerView recyclerView, ArrayList<SingleItemModel> items) {
mValues = items;
mRecyclerView = recyclerView;
}
@Override
public ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
return new ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder(view);
}
@Override
public void onViewRecycled(ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder holder) {
if (holder.mImageView.getController() != null) {
holder.mImageView.getController().onDetach();
}
if (holder.mImageView.getTopLevelDrawable() != null) {
holder.mImageView.getTopLevelDrawable().setCallback(null);
//
}
}
@Override
public void onBindViewHolder(final ImageListFragment.SimpleStringRecyclerViewAdapter.ViewHolder holder, final int position) {
SingleItemModel singleItemModel = mValues.get(position);
holder.iTemName.setText(singleItemModel.getCategory_Name());
final Uri uri = Uri.parse(singleItemModel.getProduct_Image());
holder.mImageView.setImageURI(uri);
holder.itemPrice.setText(singleItemModel.getProduct_Price());
holder.itemDescription.setText(singleItemModel.getProduct_Sale());
}
@Override
public int getItemCount() {
return mValues.size();
}
}
public void getCategoryone() {
final RequestQueue queue = Volley.newRequestQueue(getActivity());
StringRequest stringRequest = new StringRequest(Request.Method.POST, "http://proaudiobrands.com/app/feature.php",
new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.i("shabina shopping response", response);
try {
singleItemModels = new ArrayList<>();
JSONObject mainObj = new JSONObject(response);
Log.d("shabina ", response);
JSONArray Feature_product = mainObj.getJSONArray("Feature_product");
for (int i = 0; i < Feature_product.length(); i++) {
JSONObject Feature_Product = Feature_product.getJSONObject(i);
String Category_Namee = Feature_Product.getString("Category_Namee");
String Category_IDs = Feature_Product.getString("Category_IDs");
JSONArray Product_List = Feature_Product.getJSONArray("Product_List");
for (int j = 0; j < Product_List.length(); j++) {
JSONObject Category_Name = Product_List.getJSONObject(j);
if (Category_Name.getString("Category_Name").equals("Microphones")) {
category_Name = Category_Name.getString("Category_Name");
Category_ID = Category_Name.getString("Category_ID");
Product_ID = Category_Name.getString("Product_ID");
Product_Name = Category_Name.getString("Product_Name");
Product_Image = Category_Name.getString("Product_Image");
Product_Price = Category_Name.getString("Product_Price");
Product_Sale = Category_Name.getString("Product_Sale");
Cart = Category_Name.getString("Cart");
Log.e("sushil Category_Name", category_Name + " " + Category_ID + " " + Product_ID + " " + Product_Name + " " + Product_Image + " " + Product_Price + " " + Product_Sale + " " + Cart);
SingleItemModel singleItemModel1 = new SingleItemModel(category_Name, Category_ID, Product_ID, Product_Name, Product_Image, Product_Price, Product_Sale, Cart);
singleItemModels.add(singleItemModel1);
}
StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(new ImageListFragment.SimpleStringRecyclerViewAdapter(recyclerView, singleItemModels));
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("error", error.toString());
}
}) {
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("method", "feature");
params.put("userId", "PRO1");
return params;
}
};
stringRequest.setRetryPolicy(new DefaultRetryPolicy(
90000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
queue.add(stringRequest);
}
}
答案 0 :(得分：1)
用以下
替换您的MainActivitypublic class MainActivity extends AppCompatActivity {
public static int notificationCountCart = 0;
Toolbar toolbar;
ActionBar actionBar;
static ViewPager viewPager;
static TabLayout tabLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
if (toolbar != null)
setSupportActionBar(toolbar);
actionBar = getSupportActionBar();
if (actionBar != null) {
TextView textView = new TextView(this);
textView.setText("Shopping");
textView.setTextSize(20);
textView.setTypeface(null, Typeface.BOLD);
textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
textView.setGravity(Gravity.CENTER);
textView.setTextColor(getResources().getColor(R.color.white));
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setCustomView(textView);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeAsUpIndicator(new IconDrawable(this, FontAwesomeIcons.fa_angle_left).colorRes(R.color.white).actionBarSize());
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
viewPager = (ViewPager) findViewById(R.id.viewpagerrr);
viewPager.setOffscreenPageLimit(4);
tabLayout = (TabLayout) findViewById(R.id.tabs);
setupViewPager(viewPager);
tabLayout.setupWithViewPager(viewPager);
}
@Override
protected void onResume() {
super.onResume();
invalidateOptionsMenu();
}
@Override
public void onBackPressed() {
super.onBackPressed();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// Get the notifications MenuItem and
// its LayerDrawable (layer-list)
MenuItem item = menu.findItem(R.id.action_cart);
NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCountCart);
// force the ActionBar to relayout its MenuItems.
// onCreateOptionsMenu(Menu) will be called again.
invalidateOptionsMenu();
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_search) {
startActivity(new Intent(MainActivity.this, SearchResultActivity.class));
return true;
} else if (id == R.id.action_cart) {
/* NotificationCountSetClass.setAddToCart(MainActivity.this, item, notificationCount);
invalidateOptionsMenu();*/
startActivity(new Intent(MainActivity.this, CartListActivity.class));
/* notificationCount=0;//clear notification count
invalidateOptionsMenu();*/
return true;
} else if (id == android.R.id.home) {
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
// startActivity(new Intent(MainActivity.this, EmptyActivity.class));
}
return super.onOptionsItemSelected(item);
}
private void setupViewPager(ViewPager viewPager) {
Adapter adapter = new Adapter(getSupportFragmentManager());
ImageListFragment fragment = new ImageListFragment();
SpeakerFragment speakerFragment = new SpeakerFragment();
adapter.addFragment(fragment, getString(R.string.item_2));
adapter.addFragment(speakerFragment, getString(R.string.item_4));
adapter.addFragment(new HeadPhone(), getString(R.string.item_3));
adapter.addFragment(new Offer(), getString(R.string.item_1));
viewPager.setAdapter(adapter);
viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
}
static class Adapter extends FragmentPagerAdapter {
private final List<Fragment> mFragments = new ArrayList<>();
private final List<String> mFragmentTitles = new ArrayList<>();
public Adapter(FragmentManager fm) {
super(fm);
}
public void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mFragmentTitles.add(title);
}
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitles.get(position);
}
}
}