Question

我有一个像下面这样的对象数据结构：

这些是我已经检索过文档数据的代码：

DocumentReference docRef = db.collection("deyaPayUsers").document(mAuth.getUid()).collection("Split").document(mAuth.getUid()).collection("SentInvitations").document(documentId);
        docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
            @Override
            public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                if (task.isSuccessful()) {
                    DocumentSnapshot document = task.getResult();
                    if (document.exists()) {
                        Log.d(TAG, "DocumentSnapshot data: " + document.getData());

                        Object value = document.getData();// Here I added the data to the object type value 
                        System.out.println("values"+ value);


                        } else {
                        Log.d(TAG, "No such document");
                    }
                } else {
                    Log.d(TAG, "get failed with ", task.getException());
                }
            }
        });

我从Firestore数据库中检索了这些数据。现在我需要所有Invite（1,2）中的金额，电话号码和状态并添加到列表视图中。我无法先获得这些字段。之后我需要将它们添加到列表视图中。而且每当用户更新字段状态时，listview也应该更新。

Answer 1

您可以通过以下方式达到以上目的，根据您的意见，您可以获得文档ID

Invite invite = document.toObject(Invite.class).withId(document.getId());

public class Invite {

    private int amount;
    private String phoneNumber;
    private String status;


    public int getAmount() {
        return amount;
    }

    public void setAmount(int amount) {
        this.amount = amount;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }
}

Answer 2

假设您的docRef DocumentReference正确无误，要获取Amount，PhoneNumber和Status属性的值，请更改以下代码行：

Object value = document.getData();// Here I added the data to the object type value 
System.out.println("values"+ value);

到

String amount = document.getString("Amount");
String phoneNumber = document.getString("PhoneNumber");
String status = document.getString("Status");
System.out.println(amount + " / " + phoneNumber + " / " + status);

假设您想获取Invite1文档的属性值，输出将是：

10 / 9876543210 / Pending

修改：根据您的评论，我了解您希望从所有文档中获取这些属性的值，但在您的代码中，您使用的是以下参考，指向单个文档和不是整个系列。

DocumentReference docRef = db
    .collection("deyaPayUsers")
    .document(mAuth.getUid())
    .collection("Split")
    .document(mAuth.getUid())
    .collection("SentInvitations")
    .document(documentId); //Reference to a document

请参阅，调用的最后一个方法是.document(documentId)？要获取所有文档，您需要使用CollectionReference。所以请使用以下代码：

DocumentReference docRef = db
    .collection("deyaPayUsers")
    .document(mAuth.getUid())
    .collection("Split")
    .document(mAuth.getUid())
    .collection("SentInvitations").get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            for (QueryDocumentSnapshot document : task.getResult()) {
                Map<String, Object> map = document.getData();
                String amount = map.get("Amount").toString();
                String phoneNumber = map.get("PhoneNumber").toString();
                String status = map.get("Status").toString();
                System.out.println(amount + " / " + phoneNumber + " / " + status);
            }
        } else {
            Log.d(TAG, "Error getting documents: ", task.getException());
        }
    }
});

输出将是：

10 / 9876543210 / Pending
20 / 1234566789 / Pending

<强> EDIT2：

docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()) {
            DocumentSnapshot document = task.getResult();
            if (document.exists()) {
                Map<String, Object> map = document.getData();
                for (Map.Entry<String, Object> entry : map.entrySet()) {
                    Map<String, Object> m = (Map<String, Object>) entry.getValue();
                    StringBuilder s = new StringBuilder();
                    for (Map.Entry<String, Object> e : m.entrySet()) {
                        s.append(e.getValue() + " ");
                    }
                    Log.d(TAG, s.toString());
                }
            }
        }
    }
});

输出将是：

10 9876543210 Pending
20 1234566789 Pending
//And so on

Firestore：从firestore获取数据并从object获取值并将其添加到listview之后

2 个答案: