Flutter实现单选,复选和开关组件的示例代码

const Switch({
  Key? key,
  required this.value,//当前开关状态
  required this.onChanged,// 改变状态回调
  this.activeColor,// 开启全部颜色
  this.activeTrackColor,// 开启轨道的颜色
  this.inactiveThumbColor,//关闭滑块颜色
  this.inactiveTrackColor,// 关闭轨道颜色
  this.activeThumbImage,// 开启滑块图片
  this.onActiveThumbImageError,// 开启滑块图片加载失败触发
  this.inactiveThumbImage,// 关闭滑块图片
  this.onInactiveThumbImageError,// 关闭滑块图片加载失败触发
  this.thumbColor,// 可以通过不同状态设置滑块颜色
  this.trackColor,// 可以通过不同状态设置轨道颜色
  this.materialTapTargetSize,//设置组件的最小大小
  this.dragStartBehavior = DragStartBehavior.start,// 处理手势拖拽行为
  this.mouseCursor,//设置鼠标停留状态 app用不到
  this.focusColor,// 获取焦点颜色
  this.hoverColor,//指针悬停颜色 
  this.overlayColor,// 设置按压滑动覆盖上面的颜色
  this.splashRadius,// 设置点击滑动覆盖圆环的半径
  this.focusNode,//焦点控制
  this.autofocus = false,// 是否自动获取焦点

Switch(
    // activeColor: Colors.blue,
    activeTrackColor: Colors.red,
    inactiveTrackColor: Colors.green,
    // inactiveThumbColor: Colors.yellow,
    materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
    dragStartBehavior: DragStartBehavior.start,
    activeThumbImage: AssetImage("images/lbxx.png"),
    inactiveThumbImage: AssetImage("images/lbxx.png"),
    value: _switchSelected,
    onChanged: (value) {
      setState(() {
        _switchSelected = value;
      });
    }),

const Radio<T>({
  Key? key,
  required this.value,//单选按钮的值
  required this.groupValue,//当前选中的值
  required this.onChanged,//选中这个按钮的回调
  this.mouseCursor,// 鼠标悬停状态
  this.toggleable = false,//点击已选中按钮是否调用onChanged回调
  this.activeColor,// 选项按钮颜色
  this.fillColor,//设置单选框不同状态的的颜色
  this.focusColor,// 获取焦点颜色
  this.hoverColor,//指针悬停颜色
  this.overlayColor,//按压覆盖颜色
  this.splashRadius,//按压覆盖颜色的半径
  this.materialTapTargetSize,//组件最小大小
  this.visualDensity,//组件的紧凑程度
  this.focusNode,//焦点
  this.autofocus = false,//是否自动获取焦点
})

Column(
  children: [
_radioCheckBox(_dataList[0]),
_radioCheckBox(_dataList[1]),
_radioCheckBox(_dataList[2]),
_radioCheckBox(_dataList[3])
  ],
),
Row _radioCheckBox(FMRadioBean fmRadioBean) {
  return Row(
    children: [
      Radio<FMRadioBean>(
          visualDensity: VisualDensity(
              horizontal: VisualDensity.minimumDensity,
              vertical: VisualDensity.minimumDensity),
          value: fmRadioBean,
          // activeColor: Colors.red,
          fillColor: MaterialStateProperty.resolveWith((state) {
            if (state.contains(MaterialState.selected)) {
              return Colors.red;
            } else {
              return Colors.blue;
            }
          }),
          focusColor: Colors.orange,
          groupValue: groupValue,
          toggleable: false,
          onChanged: (value) {
            setState(() {
              groupValue = fmRadioBean;
              radioText = fmRadioBean.text;
            });
          }),
      Text(fmRadioBean.text)
    ],
  );
}
class FMRadioBean {
  int index;
  String text;
  bool isSelect;
  FMRadioBean(this.index, this.text, this.isSelect);
}

const Checkbox({
  Key? key,
  required this.value,// 是否被选中
  this.tristate = false,//复选框value是否可以为null
  required this.onChanged,// 选中回调
  this.mouseCursor,// 鼠标指针状态
  this.activeColor,// 选中颜色
  this.fillColor,// 不同状态颜色设置
  this.checkColor,// 对勾颜色
  this.focusColor,// 获取焦点颜色
  this.hoverColor,// 指针悬停颜色
  this.overlayColor,// 按压覆盖颜色
  this.splashRadius,// 按压覆盖半径
  this.materialTapTargetSize,//最小大小
  this.visualDensity,// 组件紧凑程度
  this.focusNode,
  this.autofocus = false,
  this.shape,// 自定义选项框样式
  this.side,// 自定义选项框边框样式
}) 

Column(
  children: [
    _checkCheckBox(_dataList[0]),
    _checkCheckBox(_dataList[1]),
    _checkCheckBox(_dataList[2]),
    _checkCheckBox(_dataList[3])
  ],
),
Text(_checkText.toString())

Row _checkCheckBox(FMRadioBean fmRadioBean) {
  return Row(
    children: [
      Checkbox(
          visualDensity: VisualDensity(
              horizontal: VisualDensity.minimumDensity,
              vertical: VisualDensity.minimumDensity),
          value: fmRadioBean.isSelect,
          activeColor: Colors.blue,
          checkColor: Colors.white,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.all(Radius.circular(6))
          ),
          side: BorderSide(color: Colors.black,width: 2,style: BorderStyle.solid),
          onChanged: (value) {
            setState(() {
              if (value == true) {
                fmRadioBean.isSelect = true;
                _checkText.add(fmRadioBean.text);
              } else {
                fmRadioBean.isSelect = false;
                _checkText.remove(fmRadioBean.text);
              }
            });
          }),
      Text(fmRadioBean.text)
    ],
  );
}