Question

此函数返回消息，它返回null我需要解决方案以返回值谢谢

public String saveData(final User user) {
        final String[] message = new String[1];
        firebaseAuth = FirebaseAuth.getInstance();
        firebaseAuth.createUserWithEmailAndPassword(user.getEmail().toString(), user.getPassword().toString())
                .addOnSuccessListener(new OnSuccessListener<AuthResult>() {
                    @Override
                    public void onSuccess(AuthResult authResult) {

                    }
                }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                message[0] = "Fail" + e.getMessage();
            }
        });

        return message[0];
    }

Answer 1

问题在于firebaseAuth.createUserWithEmailAndPassword()是异步操作-因此onSuccess()和onFailure()回调将在以后不久触发。但是开始操作后您将立即返回message[0]-这就是为什么您获得null结果的原因。为了解决该问题，您可以将回调作为参数传递给函数，并在触发回调时处理结果。例如，

public void saveData(final User user, OnSuccessListener<AuthResult> success, OnFailureListener failure) {
    final String[] message = new String[1];
    firebaseAuth = FirebaseAuth.getInstance();
    firebaseAuth.createUserWithEmailAndPassword(user.getEmail().toString(), user.getPassword().toString())
            .addOnSuccessListener(success).addOnFailureListener(failure);
}

并调用它

saveData(user, new OnSuccessListener<AuthResult>() {
                @Override
                public void onSuccess(AuthResult authResult) {
                    // TODO handle result
                }
            }, new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {
            String message = "Fail" + e.getMessage();
        }
    });

类似的东西。

自定义函数中的Android Firebase代码返回null

1 个答案: