0

所以我正在创建一个输入文本的应用程序，当我点击“提交”按钮时，它应该将每个字母转换为其各自的数字并执行数字总和以获得最终的单个数字答案。有人可以指导我如何去做吗？我是 Dart 编程语言的初学者，我似乎无法关联逻辑

 import 'package:flutter/cupertino.dart';
    import 'package:flutter/material.dart';
    import 'package:luckynumberapp/Calculate.dart';
    import 'package:luckynumberapp/about.dart';
    
    void main() {
      runApp(MyApp());
    }
    
    class MyApp extends StatefulWidget {
      @override
      _MyAppState createState() => _MyAppState();
    }
    
    class _MyAppState extends State<MyApp> {
      var name, value;
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          theme: ThemeData.dark(),
          home: Builder(
            builder: (context) => Scaffold(
              backgroundColor: Colors.black,
              appBar: AppBar(
                iconTheme: IconThemeData(color: Colors.white),
                backgroundColor: Colors.red,
                title: Text(
                  'LUCKY NUMBER',
                  style: TextStyle(fontFamily: 'Pacifico', letterSpacing: 4),
                ),
              ),
              body: Container(
                padding: EdgeInsets.fromLTRB(20, 10, 20, 30),
                child: Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: <Widget>[
                      TextField(
                        decoration: InputDecoration(
                          hintText: 'Enter a word/name',
                          labelText: 'Enter',
                        ),
                        keyboardType: TextInputType.text,
                        onChanged: (name) {
                          value = name;
                          value1 = name;
                        },
                      ),
                      RaisedButton(
                        onPressed: () {
                          Navigator.of(context).push(MaterialPageRoute(
                            builder: (context) => screen2(value: value),
                          ));
                        },
                        child: Text('Submit'),
                      ),
                    ],
                  ),
                ),
              ),
              drawer: Drawer(
                child: ListView(
                  children: <Widget>[
                    UserAccountsDrawerHeader(
                      decoration: BoxDecoration(color: Colors.red),
                      accountName: Text('Yogesh Prakash'),
                      accountEmail: Text('test@dev.com'),
                      currentAccountPicture: CircleAvatar(
                        child: Image(
                          image: AssetImage(
                              'Image/105769079_10217500208479055_1053899048265455769_n.jpg'),
                        ),
                      ),
                    ),
                    ListTile(
                        title: Text('About'),
                        onTap: () {
                          Navigator.push(
                            context,
                            MaterialPageRoute(builder: (context) => AboutPage()),
                          );
                        })
                  ],
                ),
              ),
            ),
          ),
        );
      }
    }
4

3 回答 3

0

您可以使用地图。因为它基本上是一个键值对。

前任：

var VariableName = {
  key : value, 
  key : value,
  key : value,
  key : value,
};

所以如果你想让 A = 1, B = 2, ...

var myMapName= {
  'A' : 1, 
  'B' : 2,
  'C' : 3,
  'D' : 4,
};

所以如果你想打印 1 到 A，你可以这样称呼它：

print(myMapName['A']);

所以输出将是：

1
于 2020-06-30T10:11:42.990 回答
0

您可以获得输入字符串的 ASCII 值的总和

sum=0;
String s;
for (int i = 0; i < s.length; i++) {
    sum=sum+s.codeUnitAt(i)
  }
print(sum)
于 2020-06-30T10:14:34.087 回答
0

试试这个效果很好，点击提交按钮后，总和会打印在控制台中，希望对您有所帮助

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String value;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark(),
      home: Builder(
        builder: (context) => Scaffold(
          backgroundColor: Colors.black,
          appBar: AppBar(
            iconTheme: IconThemeData(color: Colors.white),
            backgroundColor: Colors.red,
            title: Text(
              'LUCKY NUMBER',
              style: TextStyle(fontFamily: 'Pacifico', letterSpacing: 4),
            ),
          ),
          body: Container(
            padding: EdgeInsets.fromLTRB(20, 10, 20, 30),
            child: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  TextField(
                    decoration: InputDecoration(
                      hintText: 'Enter a word/name',
                      labelText: 'Enter',
                    ),
                    keyboardType: TextInputType.text,
                    onChanged: (name) {
                      value = name;
                      //value1 = name;
                    },
                  ),
                  RaisedButton(
                    onPressed: () {
                      int sum=0;
                      if(value.trim().isNotEmpty)
                      for(int i=0;i<value.length;i++)
                        (value[i].toUpperCase() == value[i]) ? sum+= (value.codeUnitAt(i) - 64) :
                        sum+= (value.codeUnitAt(i) - 96);
                      print(sum);
                      Navigator.of(context).push(MaterialPageRoute(
                        builder: (context) => screen2(value: sum),
                      ));
                    },
                    child: Text('Submit'),
                  ),
                ],
              ),
            ),
          ),
          drawer: Drawer(
            child: ListView(
              children: <Widget>[
                UserAccountsDrawerHeader(
                  decoration: BoxDecoration(color: Colors.red),
                  accountName: Text('Yogesh Prakash'),
                  accountEmail: Text('test@dev.com'),
                  currentAccountPicture: CircleAvatar(
                    child: Image(
                      image: AssetImage(
                          'Image/105769079_10217500208479055_1053899048265455769_n.jpg'),
                    ),
                  ),
                ),
                ListTile(
                    title: Text('About'),
                    onTap: () {
                      Navigator.push(
                        context,
                        MaterialPageRoute(builder: (context) => AboutPage()),
                      );
                    })
              ],
            ),
          ),
        ),
      ),
    );
  }
}
于 2020-06-30T11:10:57.780 回答