Getting "The body might complete normally, causing 'null' to be returned, but the ret-CodePudding

I get the following error message:

The body might complete normally, causing 'null' to be returned, but the return type is a potentially non-nullable type.
Try adding either a return or a throw statement at the end.

While trying to use an observable variable using the following code:

      Obx((){ElevatedButton(
        child: Text(_authMode.value == AuthMode.Login ? 'LOGIN' : 'SIGN UP'),
        onPressed: _submit,
        style: ElevatedButton.styleFrom(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(30),
          ),
          primary: Theme.of(context).primaryColor,
          padding: const EdgeInsets.symmetric(
              horizontal: 30.0, vertical: 8.0),
          onPrimary: Theme.of(context).primaryTextTheme.button!.color,
        ))},
      ),

      Obx((){ TextButton(
        child: Text(
            '${_authMode.value == AuthMode.Login ? 'SIGN UP' : 'LOGIN'} '),
        onPressed: _switchAuthMode,
        style: TextButton.styleFrom(
          padding:
              const EdgeInsets.symmetric(horizontal: 30.0, vertical: 4),
          tapTargetSize: MaterialTapTargetSize.shrinkWrap,
          textStyle: TextStyle(color: Theme.of(context).primaryColor),
        ))
      }),

I don't know how to fix it?

CodePudding user response：

You are not returning anything from the Obx lambda. But it requires a Widget to be returned. Try changing like this:

Obx((){
     return ElevatedButton(....);});

And:

 Obx((){
     return TextButton(...);});

You are just missing the return keyword.

Or you may like to use the fat arrow syntax without the return keyword like:

 Obx(()=> ElevatedButton(...));