我可以省略在Kotlin中不使用的接口方法吗?

问题描述:

如果我只对onSee感兴趣而不关心其他事件怎么办?我至少可以忽略没有返回值的方法吗?

What if I am only interested in onSee and do not care for other events? Can I at least omit the methods that have no return values?

interface EventHandler
{
    fun onSee()
    fun onHear()
    fun onSmell()
    fun onTouch()
    fun onAwake()
    fun onSleep()
}

fun addEventHandler(handler:EventHandler)
{

}

fun Main()
{
    addEventHandler(object:EventHandler
    {
        override fun onSee()
        {
            print("I see.")
        }
    })
}

确保您只能实现一个接口方法,您要做的就是在接口声明中为其他方法提供默认实现

Sure you can only implement one interface method, all you have to do is to provide a default implementation for the other methods in the interface declaration

interface EventHandler {
    fun onSee()
    fun onHear() { /* default implementation */ }
    fun onSmell(){ /* default implementation */ }
    fun onTouch(){ /* default implementation */ }
    fun onAwake(){ /* default implementation */ }
    fun onSleep(){ /* default implementation */ }
}

现在,当您创建此接口的实例时,只需为onSee()方法提供强制实施,其余为可选

Now when you create an instance of this interface you only need to provide a compulsory implementation for onSee() method, rest are optional

如果您不是原始界面的作者 您可以扩展原始接口,并为所需的方法提供默认实现

If you're not the author of the original interface You could extend the original interface and provide a default implementation for the methods you want

interface OnSeeEventHandler: EventHandler {
    override fun onHear() { /* default implementation */ }
    override fun onSmell(){ /* default implementation */ }
    override fun onTouch(){ /* default implementation */ }
    override fun onAwake(){ /* default implementation */ }
    override fun onSleep(){ /* default implementation */ }
}

并使用OnSeeEventHandler仅提供onSee方法实现