【发布时间】：2020-12-27 14:09:35
【问题描述】：
我在Fragment 中有Listview，我在其中使用ArrayAdapter 设置数据，当我使用对话框删除数据时，值在listview 中重复。我不知道该怎么做我想在对话框中单击删除按钮时刷新我的fragment，但我不知道该怎么做。我是 Android 新手，请让我知道我能做些什么解决这个问题。这是我的代码。
ListOfFaculty
public class ListOfFaculty extends Fragment {
DatabaseReference ref;
ListView listview;
List<String> store;
List<String> UserID;
String[] faculty_list;
String a;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ref = FirebaseDatabase.getInstance().getReference("Faculty");
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
final View root = inflater.inflate(R.layout.fragment_list_of_faculty, container, false);
listview = root.findViewById(R.id.lv);
store =new ArrayList<>();
UserID =new ArrayList<>();
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot postsap : dataSnapshot.getChildren() ) {
DataSnapshot data = postsap.child("name");
if(data.exists()){
a = data.getValue().toString();
}
store.add(a);
String Id = postsap.getKey();
UserID.add(Id);
}
faculty_list = new String[store.size()];
for(int i=0;i<faculty_list.length;i++){
faculty_list[i] =store.get(i);
}
if (getActivity() != null) {
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getContext(), android.R.layout.simple_spinner_item, faculty_list);
listview.setAdapter(adapter);
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(getContext(),Faculty.class);
i.putExtra("User_Id",UserID.get(position));
startActivity(i);
}
});
listview.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
String name = faculty_list[position];
Toast.makeText(getContext(), ""+UserID.get(position), Toast.LENGTH_SHORT).show();
DialogFragment dialogFragment =new MyDailogFragment();
Bundle bundle =new Bundle();
bundle.putString("Name",name);
bundle.putString("Id",UserID.get(position));
dialogFragment.setArguments(bundle);
dialogFragment.show(getChildFragmentManager(),"missiles");
return true;
}
});
return root;
}
}
这是我的对话框代码，我在 ListofFaculty fragment 中使用 .setOnItemLongClickListener 调用此 Dialog 框。
MyDailogFragment
public class MyDailogFragment extends DialogFragment {
DatabaseReference dailog;
String Id;
@NonNull
@Override
public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
Bundle bundle = getArguments();
final String name= bundle.getString("Name","");
Id = bundle.getString("Id","");
AlertDialog.Builder alertDialog = new AlertDialog.Builder(getActivity());
alertDialog.setMessage("Delete "+name+ " ?")
.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getActivity(), ""+Id, Toast.LENGTH_SHORT).show();
dailog = FirebaseDatabase.getInstance().getReference("Faculty").child(Id);
dailog.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
dataSnapshot.getRef().removeValue();
Toast.makeText(getActivity(), name+" Deleted Successfully ", Toast.LENGTH_SHORT).show();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(getActivity(), "Nothing", Toast.LENGTH_SHORT).show();
}
});
return alertDialog.create();
}
}
【问题讨论】：
标签： java android android-listview