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在onComplete方法中实现接口时出现问题

google-cloud-firestore firebase android java

Scrin · 技术社区 · 4 年前

按照我在这里创建的上一个线程: How do I set a variable inside of an onComplete method?

我仍在尝试调用我在内部设置的变量 onComplete 方法。我知道在访问该方法之间存在延迟。向我提出的一个解决方案是创建一个界面。虽然我已经成功实现了接口,但我不确定我的实现是否正确,因为我仍然会得到null。

这是我的界面:

public interface MyCallBack {
void onCallFullName(String fullName);
void onCallEmail(String Email);
}

从firebase获取数据的方法:

private void callUserCredential(MyCallBack myCallBack) {
    fAuth = FirebaseAuth.getInstance();
    fStore = FirebaseFirestore.getInstance();
    String userID = fAuth.getCurrentUser().getUid();


    DocumentReference docRef = fStore
            .collection("users")
            .document(userID);

    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 for successfully fetching data from firebase
                    Log.d(TAG,"User full name: " + document.getString("FullName"));
                    Log.d(TAG, "User email: " + document.getString("Email"));

                    String fullName = document.getString("FullName");
                    String eMail = document.getString("Email");

                    //Log for successfully setting the data into the variables
                    Log.d(TAG, "donorFullName set: " + fullName);
                    Log.d(TAG, "donorEmail set: " + eMail);

                    //Interface callback
                    myCallBack.onCallFullName(fullName);
                    myCallBack.onCallEmail(eMail);

                }
            }
        }
    });
}

最后,我调用接口:

//Create booking information
    BookingInformation bookingInformation = new BookingInformation();

    callUserCredential(new MyCallBack() {
        @Override
        public void onCallFullName(String fullName) {
            donorFullName = fullName;
        }

        @Override
        public void onCallEmail(String Email) {
            donorEmail = Email;
        }
    });

    //Log for successfully calling the interface
    Log.d(TAG, "donorFullName bookingInformation: " + donorFullName);
    Log.d(TAG, "donorEmail bookingInformation: " + donorEmail);
    bookingInformation.setDonorName(donorFullName);
    bookingInformation.setDonorEmail(donorEmail);

logcat仍然显示相同的内容:

0 回复 | 直到 4 年前

您必须在回调函数中设置DonorName()和setDonorEmail(),例如:

//Create booking information
    BookingInformation bookingInformation = new BookingInformation();

    callUserCredential(new MyCallBack() {
        @Override
        public void onCallFullName(String fullName) {
            bookingInformation.setDonorName(fullName);
            //Log for successfully calling the interface
            Log.d(TAG, "donorFullName bookingInformation: " + fullName);
        }

        @Override
        public void onCallEmail(String email) {
            bookingInformation.setDonorEmail(email);
            //Log for successfully calling the interface
            Log.d(TAG, "donorEmail bookingInformation: " + email);
        }
    });

因为当你调用log函数时,请求尚未完成!