flutter - 如何在FocusNode上设置循环

Question

我是新手。这是TextField的代码，我希望这些Focusnode通过for循环来实现，

List myFocusNode;

FormFields(hintText) {
  for (var i = 0; i < 15; i++) {
   TextField(
    focusNode: myFocusNode[i],
    textAlign: TextAlign.left,
    style: TextStyle(
      color: Color(0xFF727c8e),
      ),
    decoration: InputDecoration(
      enabledBorder: OutlineInputBorder(
        borderSide: BorderSide(color: Color(0xFF960bef)),
        ),
      focusedBorder: OutlineInputBorder(
        borderSide: BorderSide(color: Color(0xFFe34fd1)),
        ),
      labelText: hintText,
      labelStyle: TextStyle(
          color: myFocusNode[i].hasFocus ? Color(0xFFe34fd1) : Color(0xFF960bef) ,
          fontSize: 15,
          fontFamily: 'Exo2-VariableFont_wght'),
      ),
    );
   }

}

运行后出现以下错误。
I / flutter(6472):[MediaQuery]，状态:_ProfileSettingPageState＃112a0):
I / flutter(6472):方法'[]'在null上调用。
I / flutter(6472):接收者:null
I / flutter(6472):尝试调用:[](0)

我把这个叫做其他类，如下 FormFields("First Name",),请给我一个解决方案。

Answer 1

用一些FocusNodes初始化列表 myFocusNode

List<FocusNode> myFocusNode = [FocusNode, FocusNode, FocusNode, FocusNode .....];

 FormFields(hintText) {
   // expected the length of myFocusNode = 15
   for (var i = 0; i < myFocusNode.length; i++) {
    TextField(
     focusNode: myFocusNode[i],
     textAlign: ........
    );
   }
 }