How to get Current state or context in Jetpack Compose

问题

fun createListItem(itemIndex: Int) {
Padding(left = 8.dp, right = 8.dp, top = 8.dp, bottom = 8.dp) {
    FlexRow(crossAxisAlignment = CrossAxisAlignment.Center) {
        expanded(1.0f) {
            Text("Item $itemIndex")
        }
        inflexible {
            Button(
                "Button $itemIndex",
                style = ContainedButtonStyle(),
                onClick = {
                    Toast.makeText(
                        this@MainActivity,
                        "Item name $itemIndex",
                        Toast.LENGTH_SHORT
                    ).show()
                })

        }
    }
  }
}

I try to make Toast in a normal way. but I got the error I tried a lot of multiples source but failed.

回答1:

You can access to context with define ambientContext.

Example:

val context = +ambient(ContextAmbient)

回答2:

I think your never show Toast normal way. Jetpack Compose uses a custom Kotlin compiler plugin to transform these composable functions into the app's UI elements. For example, the Text() function is defined by the Compose UI library. Jetpack Compose is in very early stages of development. You can see all repo of Jetpack compose with sample and integrations test check below link

https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-master-dev/ui

For jetpack compose material demo check this link

https://android.googlesource.com/platform/frameworks/support/+/refs/heads/androidx-master-dev/ui/ui-material/integration-tests/material-demos/src/main/java/androidx/ui/material/demos