AsyncTask in Android with Kotlin

AsyncTask is an Android API, not a language feature that is provided by Java nor Kotlin. You can just use them like this if you want:

class someTask() : AsyncTask<Void, Void, String>() {
    override fun doInBackground(vararg params: Void?): String? {
        // ...
    }

    override fun onPreExecute() {
        super.onPreExecute()
        // ...
    }

    override fun onPostExecute(result: String?) {
        super.onPostExecute(result)
        // ...
    }
}

Anko's doAsync is not really 'provided' by Kotlin, since Anko is a library that uses language features from Kotlin to simplify long codes. Check here:

• https://github.com/Kotlin/anko/blob/d5a526512b48c5cd2e3b8f6ff14b153c2337aa22/anko/library/static/commons/src/Async.kt

If you use Anko your code will be similar to this:

doAsync {
    // ...
}

You can get a similar syntax to Anko's fairly easy. If you just wan't the background task you can do something like

class doAsync(val handler: () -> Unit) : AsyncTask<Void, Void, Void>() {
    override fun doInBackground(vararg params: Void?): Void? {
        handler()
        return null
    }
}

And use it like

doAsync {
    yourTask()
}.execute()