如何确定是否有人在editText上键入

Question

我正在使用android studio设计聊天应用程序，并且使用fire-base作为云服务提供商，并且我掌握了如何使监听程序（如用户在编辑文本字段中键入内容）的库存。 base将变为true，并且当用户不键入时，该值将变为false。我正在寻找此解决方案大约一个星期，但没有找到关于我的研究的任何答案。

如何放置TextWatcher？

编辑

       final Firebase firebase = new Firebase("https://my-first-sample-is.firebaseio.com/");


            editText = (EditText) findViewById(R.id.editText);

            listView = (ListView) findViewById(R.id.listView);

            listView.setAdapter(new MessageAdapter(this, Message.class, R.layout.fragment_message, firebase.child("chat")));
            editText.setAdapter(new RoomTypeAdapter(this, RoomType.class, R.layout.fragment_message1, firebase.child("Room-Typing")));

            button = (Button) findViewById(R.id.button);



            button.setOnClickListener(new View.OnClickListener() {


                @Override
                public void onClick(View view) {
  Message message = new Message();

                message.setMessage(editText.getText().toString());
                editText.setText("");
                message.setAuthor("Name");
                message.setNumMessages(numMessages);


                firebase.child("chat").push().setValue(message);


            }
        });
        editText.setImeOptions(EditorInfo.IME_ACTION_DONE);
        editText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_DONE) {

                    return true;
                }
                return false;
            }
        });
    }

Answer 1

像这样在您的edittext上实现TextWatcher

    EditText myTextBox = (EditText) findViewById(R.id.myTextBox);
  myTextBox.addTextChangedListener(new TextWatcher() {

   public void afterTextChanged(Editable s) {
   }

   public void beforeTextChanged(CharSequence s, int start, 
     int count, int after) {
   }

   public void onTextChanged(CharSequence s, int start, 
     int before, int count) {
   // Here you can trigger your another code/function about which you are asking
   }
  });

希望对您有所帮助！