尝试在 Kotlin 中传递函数参数

Question

I have a function:

fun test(){
    Timber.d("Button Clicked")
}

And I'm trying to pass this function to a fragment. Here is that field inside my fragment.

class MyFragment(val layout: Int) : Fragment() {
     var clickEvent1: (() -> Unit)? = null
}

And this is how I'm setting this field before beginning fragment transaction.

fragment.clickEvent1 = {test()}

My goal is to run this function on my button click inside my fragment.

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
     dialog_option_1.setOnClickListener { clickEvent1 }
}

There's an issue with the way I'm doing this because the "test" function does not run. Can someone point me in the right direction? Thanks

Answer 1

Use

dialog_option_1.setOnClickListener(clickEvent1)

You need to pass the lambda itself to method, so you should use () parentheses instead of {}, which create a new lambda that just does almost nothing in your case.

Answer 2

Should be

dialog_option_1.setOnClickListener { clickEvent1() }

if you want to do it like that.