装饰模式使用对象组合的方式动态改变或增加对象行为。 Go语言借助于匿名组合和非入侵式接口可以很方便实现装饰模式。 使用匿名组合，在装饰器中不必显式定义转调原对象方法。 #### decorator.go ~~~go package decorator type Component interface { Calc() int } type ConcreteComponent struct{} func (*ConcreteComponent) Calc() int { return 0 } type MulDecorator struct { Component num int } func WarpMulDecorator(c Component, num int) Component { return &MulDecorator{ Component: c, num: num, } } func (d *MulDecorator) Calc() int { return d.Component.Calc() * d.num } type AddDecorator struct { Component num int } func WarpAddDecorator(c Component, num int) Component { return &AddDecorator{ Component: c, num: num, } } func (d *AddDecorator) Calc() int { return d.Component.Calc() + d.num } ~~~ #### decorator\_test.go ~~~go package decorator import "fmt" func ExampleDecorator() { var c Component = &ConcreteComponent{} c = WarpAddDecorator(c, 10) c = WarpMulDecorator(c, 8) res := c.Calc() fmt.Printf("res %d\n", res) // Output: // res 80 } ~~~