仅限号码类型

keyboardType: TextInputType.number

和更多的选择与数字垫

keyboardType: TextInputType.numberWithOptions(decimal: true,signed: false)

这里是关于如何添加数字键盘，如何进行验证，如何添加样式，以及dart/flutter中的其他内容的所有细节。 我希望它能帮助你更好地学习。

Padding(
            padding: const EdgeInsets.all(3.0),
            child: TextFormField(
              maxLength: 10,
              keyboardType: TextInputType.number,
              validator: (value) {
                if (value.isEmpty) {
                  return 'Enter Number Please';
                }
                
                return null;
              },
              decoration: InputDecoration(
                prefixIcon: Icon(Icons.smartphone),
                prefixText: '+92',
                labelText: 'Enter Phone Number',
                contentPadding: EdgeInsets.zero,
                enabledBorder: OutlineInputBorder(),
                focusedBorder: OutlineInputBorder(
                    borderSide: BorderSide(
                      width: 2, color: Theme
                        .of(context)
                        .primaryColor,
                    )
                ),
                focusColor: Theme
                    .of(context)
                    .primaryColor,
              ),
            ),
          ),

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"),
                ],
              )),
        );
      }
    }

对于那些正在寻找使TextField或TextFormField只接受数字作为输入的人，尝试以下代码块:

用于flutter 1.20或更新版本

TextFormField(
  controller: _controller,
  keyboardType: TextInputType.number,
  inputFormatters: <TextInputFormatter>[
   // for below version 2 use this
 FilteringTextInputFormatter.allow(RegExp(r'[0-9]')), 
// for version 2 and greater youcan also use this
 FilteringTextInputFormatter.digitsOnly

  ],
  decoration: InputDecoration(
    labelText: "whatever you want",
    hintText: "whatever you want",
    icon: Icon(Icons.phone_iphone)
  )
)

对于1.20的早期版本

TextFormField(
    controller: _controller,
    keyboardType: TextInputType.number,
    inputFormatters: <TextInputFormatter>[
        WhitelistingTextInputFormatter.digitsOnly
    ],
    decoration: InputDecoration(
        labelText:"whatever you want", 
        hintText: "whatever you want",
        icon: Icon(Icons.phone_iphone)
    )
)

下面是数字键盘的代码: keyboardType: TextInputType。当你在文本框中添加这个代码时，它将打开数字键盘。

  final _mobileFocus = new FocusNode();
  final _mobile = TextEditingController();


     TextFormField(
          controller: _mobile,
          focusNode: _mobileFocus,
          maxLength: 10,
          keyboardType: TextInputType.phone,
          decoration: new InputDecoration(
            counterText: "",
            counterStyle: TextStyle(fontSize: 0),
            hintText: "Mobile",
            border: InputBorder.none,
            hintStyle: TextStyle(
              color: Colors.black,
                fontSize: 15.0.
            ),
          ),
          style: new TextStyle(
              color: Colors.black,
              fontSize: 15.0,
           ),
          );

以下是Flutter中实际手机键盘的代码:

     //Mobile
            const TextField(
              keyboardType: TextInputType.number,
              decoration: InputDecoration(
                  prefixIcon: Icon(Icons.phone), hintText: 'Mobile'),
            ),