我正在尝试更改RecyclerView的位置，但是需要更改，但是如果我转到另一个Activity或退出应用程序并再次打开它，它会告诉我正确的位置。
数据被保存到数据库SDQLite中，我从那里读取Adapter并显示到Fragment。
onMove我写了一个Log，上面写着正确的位置，哪个位置是新的。
在Log处arrayList = getSampleData()处，它总是保存位置并读取实际位置，但是ArrayList处的Fragment现在被隐藏了，它不显示我什么。
第一次，它通常显示所有项目，但是当我更改位置时，项目将被隐藏，如果我进行arrayList.add(customer)，则显示给我数据但未排序。
我使用Collections.swap来更改职位。
这是视频，您可以看到发生了什么事。
https://streamable.com/fdyyy
下面是我的代码。
Fragment.class
public class SpeedDialFragment extends Fragment {
ArrayList<Bookmark> arrayList = new ArrayList<>();
AdapterForBookmark myAdapter;
List<Bookmark> test;
View paramView;
RecyclerView myRecyclerView;
BookmarkDB mDB;
private Context mContext;
private SharedPreferences mSharedPreferences;
private SharedPreferences.Editor mEditor;
public static final String LIST_OF_SORTED_DATA_ID = "json_list_sorted_data_id";
public final static String PREFERENCE_FILE = "preference_file";
private ItemTouchHelper mItemTouchHelper;
public OnCustomerListChangedListener mListChangedListener;
@Override
public void onAttach(Context context) {
super.onAttach(context);
mContext = context;
mDB = new BookmarkDB(mContext);
mDB.getAllBookmarks();
buildBookmarkArrayListfromDB();
loadBookMarksFromXML();
}
@Nullable
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
paramView = inflater.inflate(R.layout.bookmark, container, false);
myRecyclerView = paramView.findViewById(R.id.myRecyclerView);
final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(mContext);
myRecyclerView.setLayoutManager(linearLayoutManager);
myRecyclerView.setHasFixedSize(true);
myAdapter = new AdapterForBookmark(mContext, arrayList);
final Bookmark bookmark = new Bookmark();
mSharedPreferences = getActivity()
.getSharedPreferences(PREFERENCE_FILE, Context.MODE_PRIVATE);
mEditor = mSharedPreferences.edit();
// arrayList.add(bookmark);
arrayList = getSampleData();
mListChangedListener = new OnCustomerListChangedListener() {
@Override
public void onNoteListChanged(ArrayList<Bookmark> bookmarkList) {
ArrayList<String> listOfSortedCustomerId = new ArrayList<String>();
for (Bookmark customer: arrayList){
listOfSortedCustomerId.add(customer.getId());
}
// convert the List of Longs to a JSON string
Gson gson = new Gson();
String jsonListOfSortedCustomerIds = gson.toJson(listOfSortedCustomerId);
// save to SharedPreference
mEditor.putString(LIST_OF_SORTED_DATA_ID, jsonListOfSortedCustomerIds).apply();
mEditor.apply();
}
};
myRecyclerView.setAdapter(myAdapter);
Log.d("TAG", "onCreateView: " + getSampleData());
ItemTouchHelper helper = new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(ItemTouchHelper.UP | ItemTouchHelper.DOWN, 0) {
@Override
public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder viewHolder1) {
int position_dragged = viewHolder.getAdapterPosition();
int position_target = viewHolder1.getAdapterPosition();
long id = viewHolder.getItemId();
Collections.swap(arrayList, position_dragged, position_target);
myAdapter.notifyItemMoved(position_dragged, position_target);
mListChangedListener.onNoteListChanged(arrayList);
mDB.updateOrder(id, position_target);
SharedPreferences sharedPreferences = mContext.getSharedPreferences("OrderItems", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putInt("item_positon", position_target);
editor.apply();
return false;
}
@Override
public void onSwiped(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
}
@Override
public void onSelectedChanged(@Nullable RecyclerView.ViewHolder viewHolder, int actionState) {
if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
assert viewHolder != null;
viewHolder.itemView.setBackgroundColor(Color.parseColor("#30000000"));
}
super.onSelectedChanged(viewHolder, actionState);
}
@Override
public void clearView(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder) {
viewHolder.itemView.setBackgroundColor(getResources().getColor(R.color.white));
super.clearView(recyclerView, viewHolder);
}
});
helper.attachToRecyclerView(myRecyclerView);
return paramView;
}
private void loadBookMarksFromXML() {
// MAY WISH TO ONLY DO THIS ONCE as bookmarks would be loaded OTHERWISE DELETE LINE BELOW
if (DatabaseUtils.queryNumEntries(mDB.getWritableDatabase(), BookmarkDB.TBL_BOOKMARK) > 0)
return;
try {
XmlResourceParser xpp = getResources().getXml(R.xml.bookmarks);
while (xpp.getEventType() != XmlPullParser.END_DOCUMENT) {
if (xpp.getEventType() == XmlPullParser.START_TAG) {
if (xpp.getName().equals("Bookmark")) {
Bookmark bookmark = new Bookmark();
bookmark.setName(xpp.getAttributeValue(null, "name"));
bookmark.setSearchUrl(xpp.getAttributeValue(null, "searchUrl"));
bookmark.setNativeUrl(xpp.getAttributeValue(null, "nativeUrl"));
bookmark.setId(xpp.getAttributeValue(null, "id"));
int drawableResourceId = getResources().getIdentifier(xpp.getAttributeValue(null, "icon"), "drawable", mContext.getPackageName());
bookmark.setIcon(drawableResourceId);
bookmark.setViewType(0);
}
}
xpp.next();
}
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void buildBookmarkArrayListfromDB() {
arrayList.clear();
arrayList.addAll(mDB.getAllBookmarks());
/* Bookmark bookmark = new Bookmark();
bookmark.setViewType(1);
arrayList.add(bookmark);*/
}
private ArrayList<Bookmark> getSampleData(){
//Get the sample data
ArrayList<Bookmark> customerList = arrayList;
//create an empty array to hold the list of sorted Customers
ArrayList<Bookmark> sortedCustomers = new ArrayList<Bookmark>();
//get the JSON array of the ordered of sorted customers
String jsonListOfSortedCustomerId = mSharedPreferences.getString(LIST_OF_SORTED_DATA_ID, "");
//check for null
assert jsonListOfSortedCustomerId != null;
if (!jsonListOfSortedCustomerId.isEmpty()){
//convert JSON array into a List<Long>
Gson gson = new Gson();
ArrayList<String> listOfSortedCustomersId = gson.fromJson(jsonListOfSortedCustomerId, new TypeToken<ArrayList<String>>(){}.getType());
//build sorted list
if (listOfSortedCustomersId != null && listOfSortedCustomersId.size() > 0){
for (String id: listOfSortedCustomersId){
for (Bookmark customer: customerList){
if (id.equals(customer.getId())){
sortedCustomers.add(customer);
customerList.remove(customer);
break;
}
}
}
}
//if there are still customers that were not in the sorted list
//maybe they were added after the last drag and drop
//add them to the sorted list
if (customerList.size() > 0){
sortedCustomers.addAll(customerList);
}
return sortedCustomers;
}else {
return customerList;
}
}
@Override
public void onResume() {
super.onResume();
buildBookmarkArrayListfromDB();
}
}
Adapter.class
public class AdapterForBookmark extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
public static final int ITEM_TYPE_ONE = 0;
public static final int ITEM_TYPE_TWO = 1;
ArrayList<Bookmark> arrayList;
String BASE_URL = "https://besticon-demo.herokuapp.com/icon?url=";
private Context context;
private int lastPosition = -1;
private Bookmark bookmark;
public AdapterForBookmark(Context context, ArrayList<Bookmark> arrayList, Bookmark bookmark) {
this.context = context;
this.arrayList = arrayList;
this.bookmark = bookmark;
}
public AdapterForBookmark(Context context, ArrayList<Bookmark> arrayList) {
this.context = context;
this.arrayList = arrayList;
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = null;
if (viewType == ITEM_TYPE_ONE) {
view = LayoutInflater.from(context).inflate(R.layout.speed_link_item, parent, false);
return new ViewHolder(view);
} else if (viewType == ITEM_TYPE_TWO) {
view = LayoutInflater.from(context).inflate(R.layout.not_active_item, parent, false);
return new TextViewHolder(view);
} else {
return null;
}
}
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, final int position) {
final int itemType = getItemViewType(position);
final Bookmark bookmark = (Bookmark) this.arrayList.get(position);
if (itemType == ITEM_TYPE_ONE) {
final ViewHolder viewHolder = (ViewHolder) holder;
Animation animation = AnimationUtils.loadAnimation(context, (position > lastPosition) ? R.anim.up_from_bottom : R.anim.down_from_top);
ViewHolder.tvName.startAnimation(animation);
viewHolder.tvMove.startAnimation(animation);
viewHolder.tvDel.startAnimation(animation);
viewHolder.tvIcon.startAnimation(animation);
ViewHolder.tvName.setText(arrayList.get(position).getName());
lastPosition = position;
String imageUrl = BASE_URL + arrayList.get(position).getSearchUrl() + "&size=32";
RequestOptions requestOptions = new RequestOptions();
int resID = context.getResources().getIdentifier(String.valueOf(arrayList.get(position).getIcon()), "drawable", context.getPackageName()); // if resID == 0 means the icon is not available in drawable folder
if (resID == 0) {
Glide.with(context)
.load(imageUrl)
.apply(requestOptions
.placeholder(R.drawable.default_favicon)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.fitCenter())
.into(viewHolder.tvIcon);
} else {
viewHolder.tvIcon.setImageResource(resID);
}
if (bookmark.getHidden() != null) {
viewHolder.tvDel.setImageResource(R.drawable.ic_move_add);
} else
viewHolder.tvDel.setImageResource(R.drawable.ic_move_del);
viewHolder.tvDel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bookmark.setHidden("hidden");
arrayList.remove(position);
notifyDataSetChanged();
}
});
viewHolder.tvName.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, ActivityChangeBookmark.class);
Bundle extras = new Bundle();
viewHolder.tvIcon.buildDrawingCache();
Bitmap image = viewHolder.tvIcon.getDrawingCache();
intent.putExtra("selectedNote", arrayList.get(position));
extras.putParcelable("Image", image);
intent.putExtras(extras);
v.getContext().startActivity(intent);
}
});
} else if (itemType == ITEM_TYPE_TWO) {
TextViewHolder textViewHolder = (TextViewHolder) holder;
textViewHolder.textView.setText("Inactive Bookmarks");
}
}
@Override
public int getItemViewType(int position) {
// based on you list you will return the ViewType
if (arrayList.get(position).getViewType() == 0) {
return ITEM_TYPE_ONE;
} else {
return ITEM_TYPE_TWO;
}
}
@Override
public int getItemCount() {
return arrayList.size();
}
@Override
public void onViewDetachedFromWindow(@NonNull RecyclerView.ViewHolder holder) {
super.onViewDetachedFromWindow(holder);
holder.itemView.clearAnimation();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private static TextView tvName, tvId, tvSearchUrl, tvNativeUrl;
ImageView tvIcon, tvMove, tvDel;
public ViewHolder(@NonNull View itemView) {
super(itemView);
tvName = itemView.findViewById(R.id.tvSiteTitle);
tvIcon = itemView.findViewById(R.id.ivFav);
tvMove = itemView.findViewById(R.id.ivMove);
tvDel = itemView.findViewById(R.id.ivDel);
tvDel.setVisibility(View.VISIBLE);
tvMove.setVisibility(View.VISIBLE);
}
}
public class TextViewHolder extends RecyclerView.ViewHolder {
TextView textView;
public TextViewHolder(@NonNull View itemView) {
super(itemView);
textView = itemView.findViewById(R.id.inactiveBookmark);
}
}
SQLite.DB
public class BookmarkDB extends SQLiteOpenHelper {
public static final String DBNAME = "bookmarks.db"; // The name of the database file
public static final int DBVERSION = 1; // The Database version
public static final String TBL_BOOKMARK = "bookmark";
public static final String COL_ID = BaseColumns._ID; // equates to _id
public static final String COl_NAME = "name";
public static final String COl_HIDDEN = "hidden";
public static final String COL_ICON = "icon";
public static final String COL_NATIVEURL = "nativeurl";
public static final String COL_SEARCHURL = "searchurl";
SQLiteDatabase mDB;
Context mContext;
public BookmarkDB(Context context) {
super(context, DBNAME, null, DBVERSION);
mDB = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
// The SQL to be used to create the table
String crt_bookmark_tbl_sql = "CREATE TABLE IF NOT EXISTS " + TBL_BOOKMARK + "(" +
COL_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COl_NAME + " TEXT, " +
COl_HIDDEN + " INTEGER, " +
COL_ICON + " TEXT, " +
COL_NATIVEURL + " TEXT," +
COL_SEARCHURL + " TEXT" +
")";
db.execSQL(crt_bookmark_tbl_sql); // CREATE THE TABLE
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP IF TABLE EXISTS " + DBNAME);
onCreate(db);
}
public void updateName(String newName, int id, String oldName) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "UPDATE " + TBL_BOOKMARK + " SET " + COl_NAME +
" = '" + newName + "' WHERE " + COL_ID + " = '" + id + "'" +
" AND " + COl_NAME + " = '" + oldName + "'";
db.execSQL(query);
}
public long addBookmark(long id, String name, boolean hidden, String icon, String nativeurl, String searchurl) {
ContentValues cv = new ContentValues();
cv.put(COl_HIDDEN, hidden);
cv.put(COl_NAME, name);
cv.put(COL_ICON, icon);
cv.put(COL_NATIVEURL, nativeurl);
cv.put(COL_SEARCHURL, searchurl);
return mDB.insert(TBL_BOOKMARK, null, cv);
// uses the convenience insert method that builds the SQL
}
public ArrayList<Bookmark> getAllBookmarks() {
ArrayList<Bookmark> rv = new ArrayList<>();
Cursor csr = mDB.query(TBL_BOOKMARK, null, null, null, null, null, null);
while (csr.moveToNext()) {
Bookmark b = new Bookmark();
b.setId(csr.getString(csr.getColumnIndex(COL_ID)));
int Icon = csr.getInt(csr.getColumnIndex(COL_ICON));
String name = csr.getString(csr.getColumnIndex(COl_NAME));
String searchUrl = csr.getString(csr.getColumnIndex(COL_SEARCHURL));
b.setIcon(Icon);
b.setName(name);
b.setSearchUrl(searchUrl);
b.setViewType(csr.getInt(csr.getColumnIndex(COl_NAME)));
b.setNativeUrl(csr.getString(csr.getColumnIndex(COL_NATIVEURL)));
rv.add(b);
}
return rv;
}
public void deleteBookmark(int id, String name) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "DELETE FROM " + TBL_BOOKMARK + " WHERE "
+ COL_ID + " = '" + id + "'" +
" AND " + COl_NAME + " = '" + name + "'";
Log.d("Deleted", "Item" + query);
db.execSQL(query);
}
public boolean ifNativeUrlExists(String nativeUrl) {
boolean rv = false;
String whereclause = COL_NATIVEURL + "=?";
String[] whereargs = new String[]{nativeUrl};
Cursor csr = mDB.query(TBL_BOOKMARK, null, whereclause, whereargs, null, null, null);
if (csr.getCount() > 0) {
rv = true;
}
csr.close();
return rv;
}
public Cursor getItemID(String name) {
SQLiteDatabase db = this.getWritableDatabase();
String query = "SELECT " + COL_ID + " FROM " + TBL_BOOKMARK + " WHERE " +
COl_NAME + " ='" + name + "'";
Cursor data = db.rawQuery(query, null);
return data;
}
public void updateOrder(long rowID, int newPos) {
ContentValues cv = new ContentValues();
cv.put(COL_ID, newPos);
mDB.update(TBL_BOOKMARK, cv, COL_ID + "=" + rowID, null);
}
}