如何在Dart中将动态成员作为其子级中的固定类型的类？

class FixedType {
  final String fixedProperty;

  FixedType(this.fixedProperty);
}

class DynamicMember<T> {
  T dynamicProperty;

  void setDynamicProperty(T value) {
    dynamicProperty = value;
  }

  FixedType asFixedType() {
    if (dynamicProperty is FixedType) {
      return dynamicProperty;
    } else {
      throw ArgumentError('Dynamic property is not of type FixedType');
    }
  }
}

void main() {
  var dynamicMember = DynamicMember<FixedType>();
  dynamicMember.setDynamicProperty(FixedType('example'));

  try {
    FixedType fixedType = dynamicMember.asFixedType();
    print(fixedType.fixedProperty); // 输出: example
  } catch (e) {
    print(e);
  }
}

FixedType fixedType = dynamicMember?.dynamicProperty as FixedType;
if (fixedType != null) {
  print(fixedType.fixedProperty);
} else {
  print('Dynamic property is not set or not of type FixedType');
}