AdapterList中的IndexOutOfBoundsException

Question

我试图在最近展示的AdapterList组件中组织使用动态数据的工作。作为测试，我将数据列表置于父组件的状态，并添加了一个按钮，该按钮每次单击都会使初始列表的长度减少一。

val (data, setData) = state { testFilms }

Column {
    Button(onClick = {
        setData(testFilms.dropLast(1))
    }) {
        Text("Change")
    }

    AdapterList(
        data,
        modifier = LayoutPadding(5.dp) + LayoutHeight.Fill + LayoutWidth.Fill
    ) { film ->
        FilmItemView(
            film = film,
            selectFilmAction = selectFilmAction,
            logger = logger
        )
    }
}

但是，重新组合AdapterList时出现了以下错误，而不是预期的结果：

java.lang.IndexOutOfBoundsException: Index: 2, Size: 2
    at java.util.ArrayList.get(ArrayList.java:437)
    at androidx.ui.foundation.ListState$composeChildForDataIndex$3$1.invoke(AdapterList.kt:448)
    at androidx.ui.foundation.ListState$composeChildForDataIndex$3$1.invoke(Unknown Source:0)
    at androidx.compose.ObserveKt.Observe(Observe.kt:37)
    at androidx.ui.foundation.ListState$composeChildForDataIndex$3.invoke(Unknown Source:11)
    at androidx.ui.foundation.ListState$composeChildForDataIndex$3.invoke(Unknown Source:0)
    at androidx.compose.Recomposer$recompose$1.invoke(Recomposer.kt:61)
    at androidx.compose.Recomposer$recompose$1.invoke(Recomposer.kt:19)
    at androidx.compose.ViewComposerKt.runWithCurrent(ViewComposer.kt:387)
    at androidx.compose.Recomposer.recompose(Recomposer.kt:51)
    at androidx.compose.Recomposer.access$recompose(Recomposer.kt:19)
    at androidx.compose.Recomposer$Companion.recompose$compose_runtime_release(Recomposer.kt:42)
    at androidx.compose.Composition.compose(Composition.kt:67)
    at androidx.compose.Composition.compose(Composition.kt:59)
    at androidx.compose.Compose$subcomposeInto$1.invoke(Compose.kt:253)
    at androidx.compose.Compose$subcomposeInto$1.invoke(Compose.kt:23)
    at androidx.compose.ViewComposerKt.runWithComposing(ViewComposer.kt:397)
    at androidx.compose.Compose.subcomposeInto(Compose.kt:252)
    at androidx.ui.foundation.ListState.composeChildForDataIndex-N7Qnm20(AdapterList.kt:447)
    at androidx.ui.foundation.ListState.recomposeAllChildren(AdapterList.kt:358)
    at androidx.ui.foundation.ListState.recomposeIfAttached(AdapterList.kt:352)
    at androidx.ui.foundation.AdapterListKt.AdapterList(AdapterList.kt:486)
    at com.gitlab.andrewkuryan.lab1.view.FilmListViewKt$FilmList$1$2$invoke$1.invoke(FilmListView.kt:174)
    at com.gitlab.andrewkuryan.lab1.view.FilmListViewKt$FilmList$1$2$invoke$1.invoke(Unknown Source:0)
    at androidx.compose.ObserveKt.Observe(Observe.kt:37)
    at com.gitlab.andrewkuryan.lab1.view.FilmListViewKt$FilmList$1$2.invoke(Unknown Source:20)
    at com.gitlab.andrewkuryan.lab1.view.FilmListViewKt$FilmList$1$2.invoke(Unknown Source:3)

有人知道使用此组件处理动态数据的任何方法吗？

Answer 1

如果您了解最新的 dev06 Jetpack Compose ，则有两种方法可以做到：

• 您的List<Any>必须“知道”，并且当前可用的是ModelList<Any>
• 您可以使用@Model标签创建模型，因为它们会改变状态，并且@Compososable函数会知道（使用MutableList）

示例代码：

fun addLogic(modelList: ModelList<MyModel>) {
  modelList.add(MyModel("Smith John", 10))
}

class MyModel(var name: String, var index: Int)

@Composable
fun RecycledList() { // Any name you want
  val modelList<MyModel> = modelListOf()
  var counter = 0

  addLogic(modelList)

  modelList.add(MyModel("John Doe", 99))

  MaterialTheme {
    Column {
      Container(height = 70.dp) {
         Align(alignment = Alignment.Center) {
            Button(onClick = { 
               modelList.add(MyModel("John Smith", counter++))
               // Any other logic you want
            }) {
               Text("ADD ITEM")
            }
         }
      }
      AdapterList(data = modelList) { item ->
         Center {
            Text("Hello ${item.name} - Index: ${item.index}")
         }
      },
    }
  }
}

结果：

在测试AdapterList时，我注意到IndexOutOfBoundsException删除了值，但添加时没有问题。收到回复后，我将更新我的答案。

Answer 2

这是一个错误（issue 153195921），它将由this patch在即将发布的版本中修复。

快速浏览一下，您的代码应该可以使用该补丁，尽管我无法从示例中对其进行测试。不过，它与补丁中的测试用例非常相似。