Compose BottomSheetScaffold IndexOutOfBoundsException 应用程序崩溃

Question

我搜索了与此问题相关的解决方案，但一无所获。我解决了这个问题，所以我在这里发布问题和解决方案，目的是帮助某人。

问题描述

将 Jetpack Compose 从版本更新到 后1.2.0-beta02，1.2.0-rc02屏幕上的某些内容导致应用程序崩溃。

此特定屏幕上的代码在版本之间没有更改，因此崩溃必须是由我正在使用的 Compose 组件之一引起的。我设法通过反复试验的方法找到了崩溃的根源，并发现问题出在BottomSheetScaffold组件上（带有空，有点content）。

导致崩溃的代码：

BottomSheetScaffold(
        sheetContent = { Text(text = "Some sheet content") }
    ) {
        AlertDialog(
            onDismissRequest = {
                // no-op
            },
            buttons = {
                Text(text = "here goes a button")
            }
        )
    }

崩溃日志：

2022-07-01 10:02:07.185 16257-16257/my.example.app E/AndroidRuntime: FATAL EXCEPTION: main
    Process: my.example.app, PID: 16257
    java.lang.IndexOutOfBoundsException: Index 0 is out of bounds. The list has 0 elements.
        at androidx.compose.runtime.collection.MutableVectorKt.checkIndex(MutableVector.kt:1135)
        at androidx.compose.runtime.collection.MutableVectorKt.access$checkIndex(MutableVector.kt:1)
        at androidx.compose.runtime.collection.MutableVector$MutableVectorList.get(MutableVector.kt:940)
        at androidx.compose.material.BottomSheetScaffoldKt$BottomSheetScaffoldLayout$1$1.invoke-0kLqBqw(BottomSheetScaffold.kt:447)
        at androidx.compose.material.BottomSheetScaffoldKt$BottomSheetScaffoldLayout$1$1.invoke(BottomSheetScaffold.kt:430)
        at androidx.compose.ui.layout.LayoutNodeSubcompositionsState$createMeasurePolicy$1.measure-3p2s80s(SubcomposeLayout.kt:590)
        at androidx.compose.ui.node.InnerPlaceable.measure-BRTryo0(InnerPlaceable.kt:44)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1428)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1427)
        at androidx.compose.runtime.snapshots.Snapshot$Companion.observe(Snapshot.kt:2101)
        at androidx.compose.runtime.snapshots.SnapshotStateObserver.observeReads(SnapshotStateObserver.kt:110)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeReads$ui_release(OwnerSnapshotObserver.kt:78)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeMeasureSnapshotReads$ui_release(OwnerSnapshotObserver.kt:66)
        at androidx.compose.ui.node.LayoutNode.performMeasure-BRTryo0$ui_release(LayoutNode.kt:1427)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.remeasure-BRTryo0(OuterMeasurablePlaceable.kt:94)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.measure-BRTryo0(OuterMeasurablePlaceable.kt:75)
        at androidx.compose.ui.node.LayoutNode.measure-BRTryo0(LayoutNode.kt:1366)
        at androidx.compose.foundation.layout.BoxKt$boxMeasurePolicy$1.measure-3p2s80s(Box.kt:115)
        at androidx.compose.ui.node.InnerPlaceable.measure-BRTryo0(InnerPlaceable.kt:44)
        at androidx.compose.ui.graphics.SimpleGraphicsLayerModifier.measure-3p2s80s(GraphicsLayerModifier.kt:405)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:53)
        at androidx.compose.foundation.layout.FillModifier.measure-3p2s80s(Size.kt:658)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:53)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1428)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1427)
        at androidx.compose.runtime.snapshots.Snapshot$Companion.observe(Snapshot.kt:2101)
        at androidx.compose.runtime.snapshots.SnapshotStateObserver.observeReads(SnapshotStateObserver.kt:110)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeReads$ui_release(OwnerSnapshotObserver.kt:78)
        at androidx.compose.ui.node.OwnerSnapshotObserver.observeMeasureSnapshotReads$ui_release(OwnerSnapshotObserver.kt:66)
        at androidx.compose.ui.node.LayoutNode.performMeasure-BRTryo0$ui_release(LayoutNode.kt:1427)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.remeasure-BRTryo0(OuterMeasurablePlaceable.kt:94)
        at androidx.compose.ui.node.OuterMeasurablePlaceable.measure-BRTryo0(OuterMeasurablePlaceable.kt:75)
        at androidx.compose.ui.node.LayoutNode.measure-BRTryo0(LayoutNode.kt:1366)
        at androidx.compose.foundation.layout.BoxKt$boxMeasurePolicy$1.measure-3p2s80s(Box.kt:115)
        at androidx.compose.ui.node.InnerPlaceable.measure-BRTryo0(InnerPlaceable.kt:44)
        at androidx.compose.ui.graphics.BlockGraphicsLayerModifier.measure-3p2s80s(GraphicsLayerModifier.kt:342)
        at androidx.compose.ui.node.ModifiedLayoutNode.measure-BRTryo0(ModifiedLayoutNode.kt:53)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1428)
        at androidx.compose.ui.node.LayoutNode$performMeasure$1.invoke(LayoutNode.kt:1427)
        at androidx.compose.runtime.snapshots.Snapshot$Companion.observe(Snapshot.kt:2101)

Answer 1

BottomSheetScaffold content仅包含AlertDialog导致崩溃的组件（我猜它被视为空的content，空的content将导致崩溃）。

AlertDialog将组件包装在Box组件中后，崩溃就消失了。我想参数中至少必须有一些屏幕内容content（AlertDialog可能不被视为屏幕内容，因为它被提升了 - 我不确定）。

修复崩溃的代码：

BottomSheetScaffold(
        sheetContent = { Text(text = "Some sheet content") }
    ) {
        Box {
            AlertDialog(
                onDismissRequest = {
                    // NO-OP
                },
                buttons = {
                    Text(text = "here goes a button")
                }
            )
        }
    }

参考找到崩溃原因的 Google 问题跟踪器：https://issuetracker.google.com/issues/235588730