Jetpack Compose TextField 中的 android:selectAllOnFocus

Question

传统 EditText在 Android 上支持 android:selectAllOnFocus属性，例如，当用户单击 EditText 时会选择其内容.
使用 androidx.compose.material.TextField 时如何实现此行为？在 Jetpack Compose 中？

Answer 1

您可以从 MutableInteractionSource 收集焦点状态并根据它更改选择状态:

var textFieldValue by remember { mutableStateOf(TextFieldValue("Lorem ipsum")) }
val interactionSource = remember { MutableInteractionSource() }
val isFocused by interactionSource.collectIsFocusedAsState()
LaunchedEffect(isFocused) {
    textFieldValue = textFieldValue.copy(
        selection = if (isFocused) {
            TextRange(
                start = 0,
                end = textFieldValue.text.length
            )
        } else {
            TextRange.Zero,
        }
    )
}
TextField(
    value = textFieldValue,
    onValueChange = { textFieldValue = it },
    interactionSource = interactionSource,
)