Flutter get set method

 Let's look at a simple case first:

In fact, for each member variable, dart will complete the default encapsulation of it

void main() {
  var p = Point("a");//这个默认是有一个set
  print(p.aaa);//这里默认是有一个get只是我们看不到而已
}

class Point {
  late String aaa;

  Point(this.aaa);
}

If we remove the get operation:
it cannot be accessed, and the security will be improved at this time, and the flexibility will be higher if there is a get method

//get set的使用方法：

void main() {
  var p = Point();
  p.Point1 = "dandaoya";
  //print(p.Point1);//这里无法被访问,去掉get后安全性会得到控制
}

class Point {
  late String _name;

  set Point1(String value) {
    _name = value;
  }

  //如果我们去掉了get的操作，那么就无法被访问了;
  // String get Point1 {  
  //   return "my name is ${_name}";
  // }
}

void main() {
  var rect = Rectangle(3, 4, 20, 15);
  assert(rect.left == 3);
  print('${rect.left}');
  rect.right = 12;
  print('${rect.left}');
  assert(rect.left == -8);
}

class Rectangle {
  late double left, top, width, height;

  Rectangle(this.left, this.height, this.width, this.top);

  double get right => left + width; //创建get set方法他们可以在赋值或者取值的时候进行一个计算操作
  //扩展了对属性的直接操作

  set right(double value) {
    left = value - width;
  }

  double get bottom => top + height;

  set bottom(double value) => top = value - height;
}