Flutter 在颤振中完成验证时，HelperText将消失

我需要在TextFormField下添加信息文本，我已经在TextFormField中添加了帮助器文本

我面临一个问题,

如果我没有在TextFormField中输入文本，并在验证完成后单击submit，则错误文本将出现，helpertext将消失。即使出现错误文本，我也希望helpertext出现在那里

有没有办法做到这一点？或任何其他在textformfield下添加文本的解决方案，如超文本

TextFormField(
                decoration: InputDecoration(
                  helperText:
                      'This May Include: \n1) House Rent or Loan EMI. \n2) Utilities Bills (Telephone, Broadband, Water). \n3) Education, Grocery, Home Helps. ',
                  helperStyle: TextStyle(
                    color: Colors.brown,
                    fontSize: 13,
                    fontWeight: FontWeight.bold,
                  ),
                  labelText: 'Current Monthly Expenses Total',
                  focusedBorder: OutlineInputBorder(
                    borderSide: BorderSide(color: Colors.black, width: 1.0),
                  ),
                  enabledBorder: OutlineInputBorder(
                    borderSide: BorderSide(color: Colors.black38, width: 1.0),
                  ),
                  errorBorder: new OutlineInputBorder(
                    borderSide: new BorderSide(color: Colors.red, width: 1.0),
                  ),
                  focusedErrorBorder: new OutlineInputBorder(
                    borderSide: new BorderSide(color: Colors.red, width: 1.0),
                  ),
                ),
                keyboardType: TextInputType.number,
                validator: (value) {
                  if (value == null || value.isEmpty) {
                    return 'Please enter current monthly expenses';
                  }
                  return null;
                },
                onSaved: (value) {
                  //print(value);
                  inflationRate = value.toString();
                  //double.parse(value);
                },
              ),