在使用addSnapshotListener时查看Firestore的实时变化,可以按照以下步骤进行操作:
以下是一个示例代码:
FirebaseFirestore db = FirebaseFirestore.getInstance();
CollectionReference collectionRef = db.collection("your_collection");
collectionRef.addSnapshotListener(new EventListener<QuerySnapshot>() {
@Override
public void onEvent(@Nullable QuerySnapshot querySnapshot, @Nullable FirebaseFirestoreException e) {
if (e != null) {
Log.w(TAG, "Listen failed.", e);
return;
}
for (DocumentChange change : querySnapshot.getDocumentChanges()) {
DocumentSnapshot documentSnapshot = change.getDocument();
switch (change.getType()) {
case ADDED:
Log.d(TAG, "New document: " + documentSnapshot.getId());
// 处理新增文档的逻辑
break;
case MODIFIED:
Log.d(TAG, "Modified document: " + documentSnapshot.getId());
// 处理修改文档的逻辑
break;
case REMOVED:
Log.d(TAG, "Removed document: " + documentSnapshot.getId());
// 处理删除文档的逻辑
break;
}
}
}
});
在这个示例中,我们监听了一个名为"your_collection"的集合。当该集合中的文档发生变化时,会触发onEvent方法。根据变化的类型,我们可以执行相应的逻辑。
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