如何在 Flutter 中使我的单选按钮完全充满活动颜色且没有白色边框？

Question

我想用单一颜色完全填充我的单选按钮。 像这样

目前单选按钮默认提供此布局。

那么我该如何改变这个呢？

我的代码

Radio(
                    value: 3,
                    groupValue: radioValue,
                    onChanged: onChanged,
                    fillColor: MaterialStateColor.resolveWith(
                        (states) => Colors.lightBlueAccent),
                  ),

请帮忙

Answer 1

您可以创建自己的无线电小部件来实现此目的：

class FilledRadio<T> extends StatelessWidget {
  final T value;
  final T groupValue;
  final ValueChanged<T> onChanged;
  final double radius;
  final Color color;

  FilledRadio(
      {required this.value,
      required this.groupValue,
      required this.onChanged,
      this.radius = 16,
      this.color = const Color(0xFF49EF3E)});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: GestureDetector(
        onTap: () {
          onChanged(this.value);
        },
        child: Container(
          height: this.radius * 2,
          width: this.radius * 2,
          decoration: ShapeDecoration(
            shape: CircleBorder(),
            color: color,
          ),
          child: Center(
            child: Container(
              height: (this.radius * 2) - 8,
              width: (this.radius * 2) - 8,
              decoration: ShapeDecoration(
                shape: CircleBorder(),
                color: value == groupValue
                    ? color
                    : Theme.of(context).scaffoldBackgroundColor,
              ),
            ),
          ),
        ),
      ),
    );
  }
}

您可以像这样使用它：

Row(
   mainAxisAlignment: MainAxisAlignment.center,
   children: <Widget>[
      FilledRadio(
        value: "0",
        radius: 20,
        color: Colors.redAccent,
        groupValue: _radValue,
        onChanged: (String value) {
          setState(() {
            _radValue = value;
          });
        },
      ),
      FilledRadio(
        value: "1",
        radius: 16,
        color: Colors.red,
        groupValue: _radValue,
        onChanged: (String value) {
          setState(() {
            _radValue = value;
          });
        },
      ),
      FilledRadio(
        value: "2",
        radius: 12,
        color: Colors.amber,
        groupValue: _radValue,
        onChanged: (String value) {
          setState(() {
            _radValue = value;
          });
        },
      ),
      FilledRadio(
        value: "3",
        radius: 16,
        color: Colors.green,
        groupValue: _radValue,
        onChanged: (String value) {
          setState(() {
            _radValue = value;
          });
        },
      ),
      FilledRadio(
        value: "4",
        radius: 20,
        color: Colors.greenAccent,
        groupValue: _radValue,
        onChanged: (String value) {
          setState(() {
            _radValue = value;
          });
        },
      ),
   ],
),

它看起来像：

注意：此实现仅支持 dart 2.12.0 及更高版本。如果您尝试在旧版本的 dart 中使用它，只需将构造函数更改为：

FilledRadio(
      {@required this.value,
      @required this.groupValue,
      @required this.onChanged,
      this.radius = 16,
      this.color = const Color(0xFF49EF3E)});

Answer 2

上面分享的答案效果很好。但是，就我而言，我需要在按钮旁边显示文本。为了实现这一目标，我更新了代码，如下所示：

import 'package:flutter/material.dart';

class FilledRadio<T> extends StatelessWidget {
  final T value;
  final T groupValue;
  final ValueChanged<T> onChanged;
  final double radius;
  final Color color;
  final title;

  FilledRadio({
    required this.title,
    required this.value,
    required this.groupValue,
    required this.onChanged,
    this.radius = 16,
    this.color = const Color(0xFF49EF3E),
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Padding(
          padding: const EdgeInsets.all(8.0),
          child: GestureDetector(
            onTap: () {
              onChanged(this.value);
            },
            child: Container(
              height: this.radius * 2,
              width: this.radius * 2,
              decoration: ShapeDecoration(
                shape: CircleBorder(),
                color: color,
              ),
              child: Center(
                child: Container(
                  height: (this.radius * 2) - 4,
                  width: (this.radius * 2) - 4,
                  decoration: ShapeDecoration(
                    shape: CircleBorder(),
                    color: value == groupValue
                        ? color
                        : Theme.of(context).scaffoldBackgroundColor,
                  ),
                ),
              ),
            ),
          ),
        ),
        GestureDetector(
          onTap: () {
            onChanged(this.value);
          },
          child: Text(
            title,
            style: TextStyle(fontSize: 16, color: secondaryTextColor),
          ),
        ),
      ],
    );
  }
}

使用示例

FilledRadio(
  title: "Wallet",
  radius: 10,
  value: PaymentMethod.wallet.name,
  groupValue: checkoutController
      .paymentMethod.value,
  onChanged: (value) {
    checkoutController.setPaymentMethod(
        value.toString());
  },
);

结果如下图：