[英]How to retrieve this data from firebase database
我想進入“ Categorias”文件夾中的數據的列表視圖,但是我嘗試了一切,但我無法做到這一點。
片段代碼:
myRef.addValueEventListener(new ValueEventListener() {
public static final String TAG = "TNW";
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// This method is called once with the initial value and again
// whenever data at this location is updated.
Map<String, Object> td = (HashMap<String,Object>) dataSnapshot.getValue();
list3 values = td.values();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
Toast.makeText(getActivity().getApplicationContext(), "Ese usuario ya existe ", Toast.LENGTH_SHORT).show();
}
});
非常簡單,這是獲取值的代碼。
DatabaseReference db = FirebaseDatabase.getInstance().getReference("people");
db.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot ds: dataSnapshot.getChildren()){
//get the categorias node
DataSnapshot dsCategorias = ds.child("categorias");
//loop inside the categorias node for all children
for(DataSnapshot dbValSnapshot: dsCategorias.getChildren()){
//Assuming all children have only boolean values
//getting the key and the values
String key = dbValSnapshot.getKey();
boolean value = dbValSnapshot.getValue(Boolean.class);
}
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
如果您無法理解我的代碼的任何部分,請告訴我。 謝謝
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