Kotlin类初始化

1.用lazy：

val  command : ControlModeSp  by lazy { 
     ControlModeSp()     //类的构造方法
 }

 private var  command : ControlModeSp ?= null     // 定义一个变量
    command = ControlModeSp()         // 类初始化

 private var  command : ControlModeSp = ControlModeSp()