TextField(
  controller: _controller,
  keyboardType: TextInputType.number,
  inputFormatters: <TextInputFormatter>[
  FilteringTextInputFormatter.allow(RegExp(r'[0.0-9.9]')),
 ])

TextField小部件需要设置keyboardType: 和inputFormatters: <TextInputFormatter>[FilteringTextInputFormatter。digitsOnly]只接受数字作为输入。

     TextField(
            keyboardType: TextInputType.number,
            inputFormatters: <TextInputFormatter>[
              FilteringTextInputFormatter.digitsOnly
            ], // Only numbers can be entered
          ),

在DartPad中的例子

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

    void main() => runApp(new MyApp());
    
    class MyApp extends StatelessWidget {
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          home: HomePage(),
          theme: ThemeData(primarySwatch: Colors.blue),
        );
      }
    }
    
    class HomePage extends StatefulWidget {
      @override
      State<StatefulWidget> createState() {
        return HomePageState();
      }
    }
    
    class HomePageState extends State<HomePage> {
      @override
      Widget build(BuildContext context) {
        return Scaffold(
          backgroundColor: Colors.white,
          body: Container(
              padding: const EdgeInsets.all(40.0),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Text("This Input accepts Numbers only"),
                  SizedBox(height: 20),
                  TextField(
                    decoration: InputDecoration(
                      focusedBorder: OutlineInputBorder(
                        borderSide:
                            BorderSide(color: Colors.greenAccent, width: 5.0),
                      ),
                      enabledBorder: OutlineInputBorder(
                        borderSide: BorderSide(color: Colors.red, width: 5.0),
                      ),
                      hintText: 'Mobile Number',
                    ),
                    keyboardType: TextInputType.number,
                    inputFormatters: <TextInputFormatter>[
                      FilteringTextInputFormatter.digitsOnly
                    ], // Only numbers can be entered
                  ),
                  SizedBox(height: 20),
                  Text("You can test be Typing"),
                ],
              )),
        );
      }
    }

对于那些需要在文本字段中使用货币格式的人:

只使用:，(逗号)和。(期)

并阻止符号:-(连字符，减号或破折号)

以及:⌴(空格)

在你的TextField，只需设置以下代码:

keyboardType: TextInputType.numberWithOptions(decimal: true),
inputFormatters: [BlacklistingTextInputFormatter(new RegExp('[\\-|\\ ]'))],

符号连字符和空格仍然会出现在键盘上，但会被阻塞。

如果需要使用双位数:

keyboardType: TextInputType.numberWithOptions(decimal: true),
inputFormatters: [FilteringTextInputFormatter.allow(RegExp('[0-9.,]')),],
onChanged: (value) => doubleVar = double.parse(value),

RegExp('[0-9.，]')允许0到9之间的数字，也允许逗号和点。

double.parse()将字符串转换为double。

别忘了你需要: 导入的包:颤振/ services.dart ';

TextField(
  controller: _controller,
  keyboardType: TextInputType.number,
  inputFormatters: <TextInputFormatter>[
  FilteringTextInputFormatter.allow(RegExp(r'[0.0-9.9]')),
 ])

您可以使用keyboardType参数轻松更改输入类型 你有很多可能性检查文档TextInputType 所以你可以使用号码或电话值

 new TextField(keyboardType: TextInputType.number)