Flutter-監聽輸入框獲取焦點合失去焦點事件

監聽輸入框

FocusNode _focusNode = FocusNode();

initState()

void initState() {
    _focusNode.addListener(() {
      if (_focusNode.hasFocus) {
        setState(() {
          _focusView = true;
        });
      }else{
        setState(() {
          _focusView = false;
        });
      }
    });
    super.initState();
  }

TextFormField添加

focusNode: _focusNode,