var list = List.generate(501, (int i) => i);                                                                                     
  list.shuffle();                             
  print(list);

简单而精确。

给你：

List numbers = [];
List selectedNumbers = [];
int i = 0;
while (i<500){
  numbers.add(i);
  i++
}

numbers.shuffle()
selectedNumbers.append(numbers[0])
numbers.remove(numbers[0])