如何在 flutter 中向 StatefulWidget 添加方法？

Question

我想调用这个方法但是不能。我的目的是从文本变量中获取字符串使用字符串中的单词制作列表显示列表。我希望通过这个来完成它。有没有其他方法或者我可以这样做？

class SecondRoute extends StatefulWidget {
  String text;
  //const SecondRoute({Key? key}) : super(key: key);
  SecondRoute({Key? key, required this.text}) : super(key: key);

  @override
  _SecondRouteState createState() => _SecondRouteState();


}

class _SecondRouteState extends State<SecondRoute> {
  String newT ="";
  

  List breakText(){
   newT = widget.text;
    var x = newT.split(" ");
    print(x);
    bool res = x.remove("");
    while(res == true){
      res = x.remove("");
    }
    print(x);
    return x;

  }
  List wordlist = breakText();// can not call this method
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Second Route"),
      ),
      body: Center(
        child: Text(
          "hhhh",
          // text,
          style: TextStyle(fontSize: 24),
        ),
      ),
    );
  }
}

Answer 1

你应该移动“List wordlist = breakText();”进入 initState() 或 build() 方法。

Answer 2

1-定义列表：

List wordlist ;

2-初始化：

 @override
  void initState(){
wordlist = breakText();
}

Answer 3

调用时需要初始化数据_SecondRouteState

class SecondRoute extends StatefulWidget {
  String text;
  //const SecondRoute({Key? key}) : super(key: key);
  SecondRoute({Key? key, required this.text}) : super(key: key);

  @override
  _SecondRouteState createState() => _SecondRouteState();


}

class _SecondRouteState extends State<SecondRoute> {
  String newT ="";
  

  List breakText(){
   newT = widget.text;
    var x = newT.split(" ");
    print(x);
    bool res = x.remove("");
    while(res == true){
      res = x.remove("");
    }
    print(x);
    return x;

  }
  List wordlist; // declare your list
  @override
  void initState() {
    super.initState();
    wordlist = breakText(); // initialize from here

  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Second Route"),
      ),
      body: Center(
        child: Text(
          "hhhh",
          // text,
          style: TextStyle(fontSize: 24),
        ),
      ),
    );
  }
}

如何在 flutter 中向 StatefulWidget 添加方法？

How can I add method to StatefulWidget in flutter?

flutter

dart

inheritance

parent-child

parent