我正在尝试根据微调框的选择过滤列表视图。我可以成功过滤列表视图。但是，当我尝试删除列表中的项目时，列表视图将不会刷新，甚至不会将未过滤的数据加载到列表中。以下是我到目前为止尝试过的。
我的适配器
public class NoteList extends ArrayAdapter<Notes> {
private Activity context;
private List<Notes> noteList;
public NoteList(Activity context, List<Notes> noteList){
super(context, R.layout.list_layout, noteList);
this.context = context;
this.noteList = noteList;
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View listViewItem = inflater.inflate(R.layout.list_layout, null, true);
TextView textViewCategory = (TextView) listViewItem.findViewById(R.id.textViewCategory);
// TextView textViewNote = (TextView) listViewItem.findViewById(R.id.textViewNote);
TextView textViewRating = (TextView) listViewItem.findViewById(R.id.textViewRating);
Notes note = noteList.get(position);
textViewCategory.setText(note.getNoteCategory());
// textViewNote.setText(note.getNote());
textViewRating.setText(note.getRating());
return listViewItem;
}
}
以下是我的MyNotes活动
public class MyNotes extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
ListView listViewNotes;
List<Notes> notesList;
DatabaseReference databaseNotes;
TextView category, date;
Spinner spinner;
NoteList adapter;
String display;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_notes);
Slidr.attach(this);
listViewNotes = (ListView) findViewById(R.id.listViewNotes);
category = (TextView) findViewById(R.id.textViewCategory);
notesList = new ArrayList<>();
date = (TextView) findViewById(R.id.DateTime);
spinner = (Spinner) findViewById(R.id.notes_spinner);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.notes_array, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(this);
databaseNotes = FirebaseDatabase.getInstance().getReference("notes");
databaseNotes.keepSynced(true);
String minutes = DateFormat.getDateTimeInstance().format(new Date());
date.setText(minutes);
listViewNotes.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Notes notes = notesList.get(i);
showUpdateDialog(notes.getNoteId(), notes.getNote(), notes.getRating(), notes.getNoteCategory(), notes.getCreationDateLong());
//return false;
}
});
}
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
display = adapterView.getItemAtPosition(i).toString();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
notesList.clear();
if (display.equals("Grateful")) {
notesList.clear();
Query query = reference.child("notes").orderByChild("rating").equalTo(display);
query.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
notesList.clear();
for (DataSnapshot noteSnapshot : dataSnapshot.getChildren()) {
Log.d("Grateful Datasnapshot", ":"+noteSnapshot);
Notes notes = noteSnapshot.getValue(Notes.class);
notesList.add(notes);
}
adapter = new NoteList(MyNotes.this, notesList);
listViewNotes.setAdapter(adapter);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
Toast.makeText(this, "Selected: " + display, Toast.LENGTH_SHORT).show();
}
if (display.equals("Ungrateful")) {
notesList.clear();
Query query = reference.child("notes").orderByChild("rating").equalTo(display);
query.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
notesList.clear();
// if (dataSnapshot.exists()) {
for (DataSnapshot noteSnapshot : dataSnapshot.getChildren()) {
Notes notes = noteSnapshot.getValue(Notes.class);
notesList.add(notes);
Log.d("Ungrateful Datasnapshot", ":"+noteSnapshot);
}
adapter = new NoteList(MyNotes.this, notesList);
listViewNotes.setAdapter(adapter);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
Toast.makeText(this, "Selected: " + display, Toast.LENGTH_SHORT).show();
} if (display.equals("All")){
notesList.clear();
databaseNotes.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
notesList.clear();
for (DataSnapshot noteSnapshot : dataSnapshot.getChildren()) {
if(noteSnapshot.exists()) {
Notes notes = noteSnapshot.getValue(Notes.class);
notesList.add(notes);
Log.d("All Datasnapshot", ":"+noteSnapshot);
}
}
adapter = new NoteList(MyNotes.this, notesList);
listViewNotes.setAdapter(adapter);
//adapter.notifyDataSetChanged();
// adapter.notifyDataSetInvalidated();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
Toast.makeText(this, "Selected: " + display, Toast.LENGTH_SHORT).show();
}
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
buttonDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
AlertDialog diaBox = AskOption(noteId);
diaBox.show();
alertDialog.dismiss();
}
});
}
private void deleteNote(String noteId) {
DatabaseReference drNote = FirebaseDatabase.getInstance().getReference("notes").child(noteId);
drNote.removeValue();
// notesList.clear();
// Toast.makeText(this, "Note is deleted", Toast.LENGTH_LONG).show();
}
}
正如您在上面看到的那样，我试图通过选定的值进行过滤，例如All，Grateful和Ungrateful。删除过滤的“感恩”列表中的项目后，该列表将生成未过滤的列表。我已经搜索并尝试了类似的问题，但没有任何效果。
谢谢。