Kotlin 反射与协程

Question

I need to call the method suspend fun insert(e: T) by reflection declared as follows:

interface IMutableDao<T> {

    @Insert(onConflict = OnConflictStrategy.ABORT)
    suspend fun insert(e: T)

    @Update
    suspend fun update(e: T)

    @Delete
    suspend fun delete(e: T)
}

I tried with:

val insertFun = IMutableDao::class.functions.find {
            it.name.equals("insert", true)
        }
insertFun!!.callSuspend(dao, o)

But I get the exception " Callable expects 3 arguments, but 2 were provided. ". I do not understand where the 3rd argument comes from.

UPDATE

I have found the problem. The 3rd is a Continuation instance. Does anyone know what to pass there? I couldn't find any suitable instance.

UPDATE 2

The workaround I found was to create a temporary class inside the function I call the suspended function from, like this:

val c = object : Continuation<Unit> {
override val context: CoroutineContext
get() = EmptyCoroutineContext
        override fun resumeWith(result: Result<Unit>) {
    }
}

Answer 1

You are missing the "this" parameter which is the object that the method should be called with respect to.

it should be the first argument to the method.

Answer 2

You may use suspendCoroutine with Unit as type and use the continuation instance.

GlobalScope.launch {
    suspendCoroutine<Unit> { continuation ->
        insertFun!!.callSuspend(dao, o, continuation)
    }
}