NetworkOnMainThreadException when used as a LaunchedEffect key

Question

When I use

 LaunchedEffect(Dispatchers.IO) 

I get,

NetworkOnMainThreadException

How should I use this function to run on background thread?

this is my code:

LaunchedEffect(Dispatchers.IO) {
    val input = URL("https://rezaapp.downloadseriesmovie.ir/maintxt.php").readText()
    println(input)
}

I'm using it inside my jetpack compose project

Answer 1

You should take a look at what LaunchedEffect does first. In your code, you placed Dispatchers.IO as the key and not as the Dispatcher to use.

Since LaunchedEffect will have a block of CoroutineScope.() -> Unit, you can switch thread within this block like the following :

LaunchedEffect {
    launch(Dispatchers.IO) {
        val input = URL("https://rezaapp.downloadseriesmovie.ir/maintxt.php").readText()
        println(input)
    }
}

Hopefully this is what you are looking for.