AndroidJetpack/Jetpack-Compose-Playground/docs/cookbook/textfield_changes.md

Handle changes to a TextField

In some cases, it’s useful to get the value of a textfield every time the text in a text field changes. For example, you might want to build a search screen with autocomplete functionality where you want to update the results as the user types.

Here is an example how you can do it with Compose:

@Composable
fun TextFieldDemo() {
    Column(Modifier.padding(16.dp)) {
        val textState = remember { mutableStateOf(TextFieldValue()) }
        TextField(
                value = textState.value,
                onValueChange = { textState.value = it }
        )
        Text("The textfield has this text: " + textState.value.text)
    }
}

The simplest approach is to supply an onValueChange() callback to a TextField. Whenever the text changes, the callback is invoked.

In this example, every time the TextField changes, the new text value will be saved in a state and set to the TextField and the Text.

See also:

• [Full Example Code]({{ site.samplefolder }}/material/textfield/TextFieldDemo.kt)