TA貢獻(xiàn)1801條經(jīng)驗(yàn) 獲得超16個(gè)贊
有幾種方法可以實(shí)現(xiàn)此目的。我使用以下方式：
FirebaseDatabase.getInstance()
.getReference()
.child("demografi")
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnap : dataSnapshot.getChildren()) {
YourObject object = dataSnap.getValue(YourObject.class);
// Use your object as needed
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
dataSnapshot返回被引用的子級(jí)。一旦擁有了它，您所要做的就是遍歷它們，您可以根據(jù)需要訪問“所有孩子”。
TA貢獻(xiàn)1834條經(jīng)驗(yàn) 獲得超8個(gè)贊
FirebaseDatabase.getInstance()
.getReference()
.child("demografi")
.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
/** Qty of data in demografi, this is what you want. */
long Count = dataSnapshot.getChildrenCount();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
如果您想實(shí)時(shí)監(jiān)控?cái)?shù)據(jù)計(jì)數(shù)，
您必須將[addListenerForSingleValueEvent]替換為[addValueEventListener]。
TA貢獻(xiàn)1871條經(jīng)驗(yàn) 獲得超13個(gè)贊
我會(huì)更喜歡這種方式-
String email, gender, nama;
DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("demografi");
databaseReference.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
// To get children count
dataSnapshot.getChildrenCount();
email = dataSnapshot.child("email").getValue().toString();
gender = dataSnapshot.child("gender").getValue().toString();
nama = dataSnapshot.child("nama").getValue().toString();
// and so on..
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s){
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
舉報(bào)