flutter - 如何在 TextFormField Flutter 中聚焦时清空提示文本

Question

我想让 TextFormField 中的提示文本在字段获得焦点时消失。但提示文本不会消失，直到我在字段中插入一个字符。我做了以下事情。当字段聚焦时，如何使提示文本消失？谢谢!

Container buildTextField(bool isObscure, TextEditingController textEditingController, String hintText, bool onlyNumber) {
    return Container(
      width: double.infinity,
      height: 60,
      color: MyColors.primary,
      alignment: Alignment.center,
      child: Padding(
        padding: EdgeInsets.only(left: 15, right: 10),
        child: TextFormField(
          textAlign: TextAlign.center,
          keyboardType: onlyNumber ? TextInputType.number : TextInputType.text,
          decoration: InputDecoration(
            hintText: hintText,
            hintStyle: TextStyle(
              color: Colors.white,
              fontWeight: FontWeight.w600,
            ),
            border: InputBorder.none,
          ),
          style: TextStyle(
            color: Colors.white,
            decoration: TextDecoration.none,
            fontWeight: FontWeight.w600,
          ),
          obscureText: isObscure,
          controller: textEditingController,
        ),
      ),
    );
  }

Answer 1

您可能需要添加一个监听器来监听焦点变化:

FocusNode myFocusNode = FocusNode();

myFocusNode.addListener( () {
   setState((){});
}

然后，在您的 InputDecoration 中更新值:

hintText: myFocusNode.hasFocus ? hintText : ''