Creating unbound service in Kotlin

Question

I'm trying to create a simple unbound service in kotlin, but I can't. When I override onBind() method in Java I can return null, but in kotlin it says I'm only allowed to return IBinder and not IBinder?, that means it can't be null. Any ideas how to fix that except rewriting MyService class into Java?

[SOLVED] Thank you, guys! I can realy change IBinder to IBinder?. It works!!

What version of kotlin are you using? Using 1.0.3, when I converted a service the method signature was `override fun onBind(intent: Intent): IBinder?` and generating the override in Android Studio gave me `override fun onBind(intent: Intent?): IBinder` but I was able to change that to `IBinder?` without issue — Enrico, Jul 21 '16 at 01:27

score 20 · Accepted Answer · edited Aug 15 '18 at 18:06

As Enrico mentioned you can change a type of IBinder to IBinder? and it will be still matching the interface.

An example is below:

override fun onBind(intent: Intent): IBinder? {
   return null
}

In general, be careful when using Android Studio to override Android methods. The real problem comes when it generates non-null type when the system actually can return a null reference. It causes runtime kotlin exceptions you really don't expect.

If I remember correctly I had a lot of issues when overloading Fragment class and methods related to View creation.

Creating unbound service in Kotlin

1 Answers1