flutter - 将其初始化为 dart 中的最终变量

Question

我想将一个类中的最终变量初始化为此。

Class C{
  final int variable1 = 0; //dynamically generated value
  final int variable2;

  C(): this.variable2 = this.variable1 + 1; //variable2 need access to "this" to initialize

}

Answer 1

您可以将私有(private)构造函数与公共(public)工厂构造函数一起使用。

class C {
  final int variable1;
  final int variable2;

  C._(this.variable1, this.variable2);

  factory C() {
    var v1 = Random().nextInt(10);
    return C._(v1, v1 + 1);
  }

  @override
  String toString() => 'Instance of C $variable1 $variable2';
}