android - Jetpack Compose 的 LazyVerticalGrid 是否有 span 策略

Question

我有一个带有 2 个单元格的 LazyVerticalGrid。

LazyVerticalGrid(
    cells = GridCells.Fixed(2),
    content = {
        items(moviePagingItems.itemCount) { index ->
            val movie = moviePagingItems[index] ?: return@items
            MovieItem(movie, Modifier.preferredHeight(320.dp))
        }
        renderLoading(moviePagingItems.loadState)
    }
)

我正在尝试使用 LazyGridScope 显示全宽加载的 fillParentMaxSize修饰符。

fun LazyGridScope.renderLoading(loadState: CombinedLoadStates) {
  when {
    loadState.refresh is LoadState.Loading -> {
        item {
            LoadingColumn("Fetching movies", Modifier.fillParentMaxSize())
        }
    }
    loadState.append is LoadState.Loading -> {
        item {
            LoadingRow(title = "Fetching more movies")
        }
    }
  }
}

但由于我们有 2 个单元格，加载可以占据屏幕的一半。像这样:

有没有办法让我的加载 View 占据全宽？

Answer 1

喷气背包撰写 1.1.0-beta03版本包括对 LazyVerticalGrid 的水平跨度支持.
这是示例用法:

private const val CELL_COUNT = 2

private val span: (LazyGridItemSpanScope) -> GridItemSpan = { GridItemSpan(CELL_COUNT) }

LazyVerticalGrid(
    cells = GridCells.Fixed(CELL_COUNT),
    content = {
        items(moviePagingItems.itemCount) { index ->
            val movie = moviePagingItems.peek(index) ?: return@items
            Movie(movie)
        }
        renderLoading(moviePagingItems.loadState)
    }
}

private fun LazyGridScope.renderLoading(loadState: CombinedLoadStates) {
    if (loadState.append !is LoadState.Loading) return

    item(span = span) {
        val title = stringResource(R.string.fetching_more_movies)
        LoadingRow(title = title)
    }
}

此答案的代码示例可在以下位置找到: Jetflix/MoviesGrid.kt