Jetpack compose Invalid ID 0x00000000-CodePudding

I am making a really simple app in which I make points in a map with different icons, a weather map. The problem is that the function that I use lasts a while to extract the information in another thread. So the program keeps running and the value does not update when I use it.

This is the code of the API of the weather.

private val appid = "??"
    private var icon: String = ""
    fun tiempo_ciudad(id: String, context: Context, callback: (String) -> Unit) {
        val tempUrl = "https://api.openweathermap.org/data/2.5/weather?id="   id   "&appid="   appid
        val stringRequest = StringRequest(
            Request.Method.POST,
            tempUrl,
            { response ->
                val json = JSONObject(response)
                val weather = json.getJSONArray("weather").getJSONObject(0)
                icon = "_" weather.getString("icon")
                callback(icon)
            },
            { error ->
                // maneja el error
            }
        )
        val requestQueue = Volley.newRequestQueue(context)
        requestQueue.add(stringRequest)
    }


    fun getIcon(id: String, context: Context, callback: (String) -> Unit) {

        tiempo_ciudad(id, context) {
                icon -> callback(icon)
        }
    }

And this is the code that I use to generate the point, is there some way to wait until getIcon works?

@Composable
fun generapunto(context: Context, id: String, x: Int, y:Int) {

    var icon = ""
    getIcon(id, context) { retrievedIcon ->
        icon = retrievedIcon
    }

    val resourceId = context.resources.getIdentifier(icon, "mipmap", context.packageName)
    Box( modifier = Modifier
        .fillMaxWidth()
        .fillMaxHeight()
        .padding(top = y.dp, start = x.dp)) {
        Image(
            painter = painterResource(resourceId),
            contentDescription = null,
            modifier = Modifier
                .size(50.dp)
                .clip(CircleShape)
                .background(Color(red = 222f / 255f, green = 225f / 255f, blue = 250f / 255f))
        )
    }
}

CodePudding user response：

Example:

@Composable
fun generapunto(context: Context, id: String, x: Int, y:Int) {
    var icon by remember { mutableStateOf("") }
    LaunchedEffect(Unit) {
        getIcon(id, context) { retrievedIcon ->
            icon = retrievedIcon
        }
    }
    if(icon.isNotBlank()) {
        val resourceId = context.resources.getIdentifier(icon, "mipmap", context.packageName)
        Box( modifier = Modifier
            .fillMaxWidth()
            .fillMaxHeight()
            .padding(top = y.dp, start = x.dp)) {
            Image(
                painter = painterResource(resourceId),
                contentDescription = null,
                modifier = Modifier
                    .size(50.dp)
                    .clip(CircleShape)
                    .background(Color(red = 222f / 255f, green = 225f / 255f, blue = 250f / 255f))
            )
        }
    }
}