flutter - dart 中的 .. 运算符是什么？

Question

Widget customWidget(int position){
    return Transform(
    transform: Matrix4.identity()..rotateY(position),
    child: Container(
      color: position % 2 == 0 ? Colors.lightBlueAccent: Colors.black87,
    ),
  )
}

Matrix4.identity()..rotateY(position) 中的.. 是什么？

Answer 1

Cascade notation

来自官方文档

Cascades (..) allow you to make a sequence of operations on the same object.

In addition to function calls, you can also access fields on that same object. This often saves you the step of creating a temporary variable and allows you to write more fluid code.