EditText监听键盘输入

<EditText
                android:imeOptions="actionDone"/>

        myCourse_roomId_input.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                //回车键
                if(actionId == EditorInfo.IME_ACTION_DONE){
                    Intent intent = new Intent(getActivity(), TopicInfoActivity.class);
                    intent.putExtra(IntentKey.topicId, myCourse_roomId_input.getText().toString());
                    startActivity(intent);
                }
                return true;
            }
        });

myCourse_roomId_input.addTextChangedListener(new TextWatcher() {
            private CharSequence temp;

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                temp = s;
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {
                if (temp.length() > 0) {//限制长度
                    myCourse_roomId_clear.setVisibility(View.VISIBLE);
                } else {
                    myCourse_roomId_clear.setVisibility(View.GONE);
                }
            }
        });