如果你使用的是badges flutter软件包的最新版本。您需要定义BadgeStyle到badgeStyle属性。检查一下这个，告诉我它是否解决了你的问题。

Badge(
      position: badges.BadgePosition.topEnd(top: -10, end: -12),
      showBadge: true,
      ignorePointer: false,
      onTap: () {},
      badgeContent: // this enebles what you put inside badge such as numbers, icons etc...
          Icon(Icons.check, color: Colors.white, size: 10),
      badgeAnimation: badges.BadgeAnimation.rotation(
        animationDuration: Duration(seconds: 1),
        colorChangeAnimationDuration: Duration(seconds: 1),
        loopAnimation: false,
        curve: Curves.fastOutSlowIn,
        colorChangeAnimationCurve: Curves.easeInCubic,
      ),
 badgeStyle: BadgeStyle( // this provides you badge shape, color etc. 
        shape: badges.BadgeShape.square,
        badgeColor: Colors.blue,
        padding: EdgeInsets.all(5),
        borderRadius: BorderRadius.circular(4),
        borderSide: BorderSide(color: Colors.white, width: 2),
        borderGradient: badges.BadgeGradient.linear(
            colors: [Colors.red, Colors.black]),
        badgeGradient: badges.BadgeGradient.linear(
            colors: [Colors.blue, Colors.yellow],
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
        ),
        elevation: 0,
      ),
child:Container()
)