尝试在Android上的Firebase数据库中更改值时循环

Question

我目前正在尝试编写一个消息传递应用程序,并发现了一个我已经被困了两个星期的错误而且无法到达任何地方.

该应用程序的工作方式如下:联系用户时,应将两个用户的状态设置为"已阻止",以便其他任何人都无法联系他们.这是我在程序中实现它的方式:

发送按钮:

openNewChatButton = (Button) findViewById(R.id.mainSendButton);
        openNewChatButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String checkText = sendMainMessage.getText().toString();
                if (checkText.isEmpty()) {
                    Toast.makeText(MainActivity.this, "Bitte verfasse vorher eine Nachricht.", Toast.LENGTH_SHORT).show();
                } else {
                    sendMessageToUser();
                }
            }
        });

创建消息并发送它:

public void sendMessageToUser() {
        mUsersDatabaseForRandomChatUser.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                key = sampleUserID;
                if (current_uid.equals(key) || key == null || key == "") {
                    Toast.makeText(MainActivity.this, "Keinen passenden Chatpartner gefunden!", Toast.LENGTH_SHORT).show();
                } else {
                    Intent newMessageIntent = new Intent(MainActivity.this, ChatActivity.class);
                    newMessageIntent.putExtra("chatuser_id", key);
                    newMessageIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                    newMessageIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    sendChatMessage();
                    finish();
                    setYouChatID();
                    changeStateOfUserToBlocked();
                    startActivity(newMessageIntent);

                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        });
    }



private void sendChatMessage() {
        String message = sendMainMessage.getText().toString();
        if (!TextUtils.isEmpty(message)) {
            String current_user_ref = "messages/" + current_uid + "/" + key;
            String chat_user_ref = "messages/" + key + "/" + current_uid;

            DatabaseReference user_message_push = mRootReference.child("Messages").child(current_uid).child(key).push();
            String push_id = user_message_push.getKey();

            Map messageMap = new HashMap();
            messageMap.put("message", message);
            messageMap.put("seen", false);
            messageMap.put("type", "text");
            messageMap.put("time", ServerValue.TIMESTAMP);
            messageMap.put("from", current_uid);

            sendMainMessage.setText("");

            Map messageUserMap = new HashMap();
            messageUserMap.put(current_user_ref + "/" + push_id, messageMap);
            messageUserMap.put(chat_user_ref + "/" + push_id, messageMap);

            mRootReference.updateChildren(messageUserMap, new DatabaseReference.CompletionListener() {
                @Override
                public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
                    if (databaseError != null)
                        Log.d("CHAT_LOG", databaseError.getMessage().toString());
                }
            });

        }
    }

更改用户的状态并设置当前的chatpartner:

private void setYouChatID() {
    DatabaseReference youChatID = mRootReference.child("Users").child(mAuth.getCurrentUser().getUid()).child("youchatid");
    youChatID.setValue(key);

    DatabaseReference youChatIDChatUser = mRootReference.child("Users").child(key).child("youchatid");
    youChatIDChatUser.setValue(current_uid);
}

private void changeStateOfUserToBlocked() {
    DatabaseReference stateDatabaseChatUser = mRootReference.child("Users").child(key).child("status");
    stateDatabaseChatUser.setValue("blocked");

    DatabaseReference stateDatabaseUser = mRootReference.child("Users").child(mAuth.getCurrentUser().getUid()).child("status");
    stateDatabaseUser.setValue("blocked");
}

到这里一切都很完美.

现在,当聊天关闭时,两个用户的状态应该设置为"空闲",并且当前的chatPartner(youchatid)应该设置为"default".

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mAuth = FirebaseAuth.getInstance();
        mCurrentUserId = mAuth.getCurrentUser().getUid();
        mRootReference = FirebaseDatabase.getInstance().getReference();
        mChatUserId = getIntent().getStringExtra("giveUserChatID");

        setContentView(R.layout.activity_securty_pop_up);
        bestaetigenButton = findViewById(R.id.bestaetigenButton);
        bestaetigenButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(SecurtyPopUpActivity.this, MainActivity.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
                finish();
                startActivity(intent);
                changeStateOfUserToFree();
                removeYouChatID();


            }
        });
    }

   public void changeStateOfUserToFree() {
        DatabaseReference stateDatabaseChatUser = mRootReference.child("Users").child(mChatUserId).child("status");
        stateDatabaseChatUser.setValue("free");

        DatabaseReference stateDatabaseUser = mRootReference.child("Users").child(mAuth.getCurrentUser().getUid()).child("status");
        stateDatabaseUser.setValue("free");
    }

  public void removeYouChatID() {
        DatabaseReference youChatID = mRootReference.child("Users").child(mAuth.getCurrentUser().getUid()).child("youchatid");
        youChatID.setValue("default");

        DatabaseReference youChatIDChatUser = mRootReference.child("Users").child(mChatUserId).child("youchatid");
        youChatIDChatUser.setValue("default");
    }

这正是问题开始的地方!

看起来好像程序在这一点上陷入了循环.两个属性都会短暂更改,但会返回旧值并再次打开活动.

但是,如果我关闭智能手机上的所有任务(包括我的应用程序)并再次尝试相同的操作,它可以正常工作.然而,在第一次之后,它不再起作用并且循环重新开始,正如您从视频中看到的那样.

因为这不容易理解,我在这里添加了一个视频:https: //www.youtube.com/watch？v = fNgjYbgB44w

我不止绝望,只是找不到解决这个问题的方法？也许你们其中一个人会有一个想法.

Answer 1

我无法相信解决方案是如此"简单".我一直认为setYouChatID()方法中的ValueEventListeners 是错误的.然而,在该sendMessageToUser()方法中仍然存在addValueEventListener()而不是addListenerForSingleValueEvent().我解决了这个问题后,问题就消失了!