如何从Firestore数据库获取文档ID [英] How to get document id from firestore database

问题描述

我正在尝试通过调用 doc.getId()来检索文档ID，但无法从此代码中调用它

I'm trying to retrieve a document id by calling doc.getId() but I can't call it from this code

        db.collection("Pegawai").addSnapshotListener(new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(@Nullable QuerySnapshot queryDocumentSnapshots, @Nullable FirebaseFirestoreException e) {
                if(e != null) {
                    Log.d(TAG, e.toString());
                }
                if (queryDocumentSnapshots != null) {
                    for (DocumentChange doc: queryDocumentSnapshots.getDocumentChanges()) {
                        if (doc.getType() == DocumentChange.Type.ADDED) {
                            Pegawai pegawai = doc.getDocument().toObject(Pegawai.class);
                            pegawai.setId(doc.getId());
                            pegawaiList.add(pegawai);

                            pegawaiListAdapter.notifyDataSetChanged();
                        }
                    }
                }
            }
        });

我已经尝试过此代码，并且显然可以用此代码调用 doc.getId()，但是此代码根本没有填充我的 recyclerview

I've tried this code, and apparently, I can call doc.getId() with this code, but this code isn't populating my recyclerview at all

        db.collection("Pegawai").addSnapshotListener(new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(@Nullable QuerySnapshot queryDocumentSnapshots, @Nullable FirebaseFirestoreException e) {
                if(e != null) {
                    Log.d(TAG, e.toString());
                }
                if (queryDocumentSnapshots != null) {
                    for (DocumentSnapshot doc : queryDocumentSnapshots) {
                        Pegawai pegawai = doc.toObject(Pegawai.class);
                        pegawai.setId(doc.getId());
                        pegawaiList.add(pegawai);
                    }
                }
            }
        });

推荐答案

一个 DocumentChange 对象具有 getDocument()，它返回 DocumentSnapshot 的子类.这意味着它还具有getId()方法.因此，您应该能够使用 doc.getDocument().getId()来获取正在处理的文档的ID.

A DocumentChange object has a method getDocument() which returns a QueryDocumentSnapshot object. This is a subclass of DocumentSnapshot which means it also has a getId() method. So you should be able to use doc.getDocument().getId() to get the ID of the document being processed.

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