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'),
            ),

设置键盘和验证器

String numberValidator(String value) {
  if(value == null) {
    return null;
  }
  final n = num.tryParse(value);
  if(n == null) {
    return '"$value" is not a valid number';
  }
  return null;
}

new TextFormField(
    keyboardType: TextInputType.number, 
    validator: numberValidator, 
    textAlign: TextAlign.right
    ...

https://docs.flutter.io/flutter/material/TextFormField/TextFormField.html https://docs.flutter.io/flutter/services/TextInputType-class.html

只需将此添加到您的TextFormField

  keyboardType: TextInputType.number,
  inputFormatters: <TextInputFormatter>[
  FilteringTextInputFormatter.allow(RegExp(r'[0-9]')), ],

的例子,

TextFormField(
        controller: textController,
        onChanged: (value) {
         print(value);
        },
        keyboardType: TextInputType.number,
        inputFormatters: <TextInputFormatter>[
          FilteringTextInputFormatter.allow(RegExp(r'[0-9]')),
        ],
      ),

我需要en IntegerFormField与最小/最大的控制。最大的问题是当焦点改变时，oneditingcomplete没有被调用。以下是我的解决方案:

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

class IntegerFormField extends StatefulWidget {
  final int value, min, max;
  final InputDecoration decoration;
  final ValueChanged<TextEditingController> onEditingComplete;
  IntegerFormField({@required this.value, InputDecoration decoration, onEditingComplete, int min, int max})
      : min = min ?? 0,
        max = max ?? maxIntValue,
        onEditingComplete = onEditingComplete ?? ((_) {}),
        decoration = decoration ?? InputDecoration()
  ;

  @override
  _State createState() => _State();
}

class _State extends State<IntegerFormField> {
  final TextEditingController controller = TextEditingController();

  @override
  void initState() {
    super.initState();
    controller.text = widget.value.toString();
  }

  @override
  void dispose() {
    super.dispose();
  }

  void onEditingComplete() {
    {
      try {
        if (int.parse(controller.text) < widget.min)
          controller.text = widget.min.toString();
        else if (int.parse(controller.text) > widget.max)
          controller.text = widget.max.toString();
        else
          FocusScope.of(context).unfocus();
      } catch (e) {
        controller.text = widget.value.toString();
      }
      widget.onEditingComplete(controller);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Focus(
      child: TextFormField(
        controller: controller,
        inputFormatters: [FilteringTextInputFormatter.digitsOnly],
        keyboardType: TextInputType.number,
        decoration: widget.decoration,
      ),
      onFocusChange: (value) {
        if (value)
          controller.selection = TextSelection(baseOffset: 0, extentOffset: controller.value.text.length);
        else
          onEditingComplete();
      },
    );
  }
}

为避免粘贴的不是数字值，添加后

keyboardType: TextInputType.number

这段代码:

inputFormatters: [FilteringTextInputFormatter.digitsOnly] 

从https://api.flutter.dev/flutter/services/FilteringTextInputFormatter-class.html

下面是Android上实际的手机键盘代码:

按键部分:keyboardType: TextInputType.phone，

  TextFormField(
    style: TextStyle(
      fontSize: 24
    ),
    controller: _phoneNumberController,
    keyboardType: TextInputType.phone,
    decoration: InputDecoration(
      prefixText: "+1 ",
      labelText: 'Phone number'),
    validator: (String value) {
      if (value.isEmpty) {
        return 'Phone number (+x xxx-xxx-xxxx)';
      }
      return null;
    },
  ),