error Error:

The argument type 'List?' can't be assigned to the parameter type 'List' because 'List?' is nullable and 'List

CodePudding user response：

alarm.gradientColors is not guaranteed to be not null. If it can never be null you shouldn't define it as nullable. If it should be nullable but you are sure it's not null at that point of code, just add an ! behind it like:

colors: alarm.gradientColors!

CodePudding user response：

I will encourage to do a null check before using ! or just provide default value on null cases like

colors: alarm.gradientColors?? [Colors.red,Colors.blue], //default color