why icon widget wont accept null?-CodePudding

i created a button widget and i want the icon of my button to be optional. so when i wanna write condition for it ,it wont accept it. here is my code:

import 'package:flutter/material.dart';

Widget CustomButtom({
  String? title,
  EdgeInsetsGeometry? paddin,
  EdgeInsetsGeometry? margin,
  double? width,
  double? height,
  Color? backgroundColor,
  dynamic? onPress,
  Color? fontColor,
  double? fontsize,
  double borderRaidius = 10,
  bool showIcon = true,
  Icon? buttonIcons,
}) {
  return Container(
    width: width,
    height: height,
    child: Directionality(
      textDirection: TextDirection.rtl,
      child: ElevatedButton.icon(
        style: ElevatedButton.styleFrom(
            backgroundColor: backgroundColor,
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(borderRaidius),
            )),
        onPressed: onPress,
        icon: showIcon? buttonIcons!:null,
        label: Text(
          '$title',
          style: TextStyle(fontSize: 20),
        ),
      ),
    ),
  );
}

and this is the error im getting

The argument type 'Icon?' can't be assigned to the parameter type 'Widget'.

CodePudding user response：

I'd suggest splitting it up to two different widgets then. Use a normal ElevatedButton when there's showIcon false, like:

return Container(
  width: width,
  height: height,
  child: Directionality(
    textDirection: TextDirection.rtl,
    child: showIcon
        ? ElevatedButton.icon(
            style: ElevatedButton.styleFrom(
                backgroundColor: backgroundColor,
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(borderRaidius),
                )),
            onPressed: onPress,
            icon: buttonIcons!,
            label: Text(
              '$title',
              style: TextStyle(fontSize: 20),
            ),
          )
        : ElevatedButton(
            style: ElevatedButton.styleFrom(
                backgroundColor: backgroundColor,
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(borderRaidius),
                )),
            onPressed: onPress,
            child: Text(
              '$title',
              style: TextStyle(fontSize: 20),
            ),
          ),
  ),
);

Note that you will get an exception when you have showIcon as true but buttonIcons as null. Maybe it's better to leave out the showIcon and just check on buttonIcons being null or not to decide between the two. So like:

return Container(
  width: width,
  height: height,
  child: Directionality(
    textDirection: TextDirection.rtl,
    child: buttonIcons != null
        ? ElevatedButton.icon(
            style: ElevatedButton.styleFrom(
                backgroundColor: backgroundColor,
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(borderRaidius),
                )),
            onPressed: onPress,
            icon: buttonIcons,
            label: Text(
              '$title',
              style: TextStyle(fontSize: 20),
            ),
          )
        : ElevatedButton(
            style: ElevatedButton.styleFrom(
                backgroundColor: backgroundColor,
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(borderRaidius),
                )),
            onPressed: onPress,
            child: Text(
              '$title',
              style: TextStyle(fontSize: 20),
            ),
          ),
  ),
);