修饰符应该用大写还是小写：首选约定是什么？

Question

我们在项目讨论中遇到了一个障碍，即注入的参数修饰符是否应该只影响顶级组件或所有组件。您能提供任何意见吗？

@Composable
fun HomeScreen(
    modifier: Modifier = Modifier,
    homeViewModel: HomeViewModel = viewModel(),
    navigateToGoalReading: () -> Unit,
    navigateToDetailEvent: () -> Unit,
) {
    val titleTextState by homeViewModel.titleTextState.collectAsState()
    val contentTextState by homeViewModel.contentTextState.collectAsState()
    val goalBookRead by homeViewModel.goalBookRead.collectAsState()
    val readingGoalGraphDataList by homeViewModel.goalReadingGraphDataList.collectAsState()
    val bookKingOfTheMonthDataList by homeViewModel.bookKingOfTheMonthDataList.collectAsState()

    MindWayAndroidTheme { colors, _ ->
        Column(
            verticalArrangement = Arrangement.spacedBy(20.dp, Alignment.Top),
            horizontalAlignment = Alignment.CenterHorizontally,
            modifier = modifier
                .background(color = colors.WHITE)
                .fillMaxSize()
                .padding(horizontal = 24.dp)
        ) {
            HomeNoticeCard(
                titleText = titleTextState,
                content = contentTextState,
                onClick = navigateToDetailEvent,
                modifier = Modifier
                    .height(100.dp)
                    .fillMaxWidth(),
            )
            HomeGoalReadingChart(
                readNumberList = readingGoalGraphDataList,
                onClick = navigateToGoalReading,
                goalBookRead = goalBookRead,
                modifier = Modifier
                    .fillMaxWidth()
                    .height(211.dp),
            )
            HomeReadersOfTheMonthChart(
                bookKingOfTheMonthData = bookKingOfTheMonthDataList,
                modifier = Modifier
                    .height(239.dp)
                    .fillMaxWidth(),
            )
        }
    }
}

VS

@Composable
fun HomeScreen(
    modifier: Modifier = Modifier,
    homeViewModel: HomeViewModel = viewModel(),
    navigateToGoalReading: () -> Unit,
    navigateToDetailEvent: () -> Unit,
) {
    val titleTextState by homeViewModel.titleTextState.collectAsState()
    val contentTextState by homeViewModel.contentTextState.collectAsState()
    val goalBookRead by homeViewModel.goalBookRead.collectAsState()
    val readingGoalGraphDataList by homeViewModel.goalReadingGraphDataList.collectAsState()
    val bookKingOfTheMonthDataList by homeViewModel.bookKingOfTheMonthDataList.collectAsState()

    MindWayAndroidTheme { colors, _ ->
        Column(
            verticalArrangement = Arrangement.spacedBy(20.dp, Alignment.Top),
            horizontalAlignment = Alignment.CenterHorizontally,
            modifier = modifier
                .background(color = colors.WHITE)
                .fillMaxSize()
                .padding(horizontal = 24.dp)
        ) {
            HomeNoticeCard(
                titleText = titleTextState,
                content = contentTextState,
                onClick = navigateToDetailEvent,
                modifier = modifier
                    .height(100.dp)
                    .fillMaxWidth(),
            )
            HomeGoalReadingChart(
                readNumberList = readingGoalGraphDataList,
                onClick = navigateToGoalReading,
                goalBookRead = goalBookRead,
                modifier = modifier
                    .fillMaxWidth()
                    .height(211.dp),
            )
            HomeReadersOfTheMonthChart(
                bookKingOfTheMonthData = bookKingOfTheMonthDataList,
                modifier = modifier
                    .height(239.dp)
                    .fillMaxWidth(),
            )
        }
    }
}

我已经研究了“now in android”和 Chris Banes 的文章“Always Provide a Modifier parameter”，以及 Google Open Source 的“Jetpack Compose API 指南”，但我找不到令人信服的答案。我非常感谢明确的答案。谢谢你

Answer 1

请查看有关

Modifier

的文档：

最佳实践是让所有可组合项接受修饰符参数，并将该修饰符传递给其第一个发出 UI 的子项。

因此，根据惯例，您应该将传递到可组合项中的

Modifier

 应用于最顶层的嵌套可组合项，在您的情况下是 

Column

。

但是，在某些情况下，传入应用于某些嵌套子级的修饰符可能是完全合理的。然后，我建议以不同的方式命名参数（而不是“修饰符”），例如

@Composable
MyComposable(
    modifier: Modifier,        // Modifier applied to first nested Composable
    childModifier: Modifier    // Modifier applied to some deeply nested Composable
) {
    // ...
}