Jetpack Compose 约束布局约束不链接

Question

我在 Jetpack Compose 中使用 constrainAs 将 wifi 选项列表限制在父视图的顶部，然后再到文本视图的底部。从照片中可以看出，我的列表并没有被限制在父级的顶部或它下面的文本视图，甚至被向上推离屏幕？

供参考，'list' 是 wifi 选项列表，'text1' 是以“Select your wifi”开头的文本视图

@Composable
fun ScanWifiScreen(wifiList: List<WifiOption>, onClick: (WifiOption) -> Unit) {
ConstraintLayout(
    modifier = Modifier
        .fillMaxSize()
        .background(colorResource(id = R.color.background))
) {

    val (list, text1, text2, progressIndicator) = createRefs()

    WifiList(
        wifiOptions = wifiList,
        onClick = onClick,
        modifier = Modifier
            .constrainAs(list) {
                top.linkTo(parent.top, margin = 8.dp)
                bottom.linkTo(text1.top)
                start.linkTo(parent.start)
                end.linkTo(parent.end)
            }
            .background(colorResource(id = R.color.background))
            .fillMaxHeight())

    Text(
        text = stringResource(id = R.string.select_wifi),
        modifier = Modifier
            .wrapContentSize()
            .padding(bottom = 16.dp)
            .constrainAs(text1) {
                bottom.linkTo(text2.top)
                start.linkTo(parent.start)
                end.linkTo(parent.end)
            },
        style = TextStyle(
            fontFamily = FontFamily(Font(R.font.quicksand_regular)),
            fontSize = 20.sp,
            color = colorResource(id = R.color.main_text),
            letterSpacing = 0.22.sp,
            textAlign = TextAlign.Center,
            lineHeight = 32.sp
        )
    )
    Text(
        text = stringResource(id = R.string.cant_see_network),
        modifier = Modifier
            .wrapContentSize()
            .padding(bottom = 32.dp)
            .constrainAs(text2) {
                bottom.linkTo(progressIndicator.top)
                start.linkTo(parent.start)
                end.linkTo(parent.end)
            },
        style = TextStyle(
            fontFamily = FontFamily(Font(R.font.quicksand_regular)),
            fontSize = 16.sp,
            color = colorResource(id = R.color.sub_text),
            letterSpacing = 0.18.sp,
            textAlign = TextAlign.Center,
            lineHeight = 24.sp
        )
    )

    ProgressIndicator2(
        progression = 3,
        modifier = Modifier.constrainAs(progressIndicator) {
            bottom.linkTo(parent.bottom)
            start.linkTo(parent.start)
            end.linkTo(parent.end)
        })
   }
}

Answer 1

在您的列表中删除 .fillMaxHeight() 修饰符并添加约束 height = Dimension.fillToConstraints

 WifiList(
     //....
     modifier = Modifier
            .constrainAs(list) {
                top.linkTo(parent.top, margin = 8.dp)
                bottom.linkTo(text1.top)
                start.linkTo(parent.start)
                end.linkTo(parent.end)
                height = Dimension.fillToConstraints
            }
      )