Passing lambda instead of interface
As @zsmb13 said, SAM conversions are only supported for Java interfaces. You could create an extension function to make it work though: // Assuming the type of dataManager is DataManager. fun DataManager.createAndSubmitSendIt(title: String, message: String, progressListener: (Long) -> Unit) { createAndSubmitSendIt(title, message, object : ProgressListener { override fun transferred(bytesUploaded: Long) { progressListener(bytesUploaded) } }) } … Read more