[英]Changing target SDK from 28 to 29 results in BLE scan not working
[英]ClassCastException when upgrading SDK from 28 to 29
我對這個 function 有這個奇怪的問題。 當我以 SDK 28 為目標時,沒有問題,也沒有發生崩潰。 這是目標 SDK 28 的工作代碼。
override fun getChildList(): List<Any> {
val itemsWithSubCats: MutableList<in Any> = ArrayList(items)
if (subCategories?.isNotEmpty() == true) {
itemsWithSubCats.add(ArrayList<Any>(subCategories))
}
return itemsWithSubCats.toList() as List<Any>
}
我已將發布版本上傳到 Playstore,但遇到了升級 SDK 問題。 於是我升級到了29個SDK,導致與之前的function編譯出錯,所以我將其修復為以下一個:
override fun getChildList(): List<Any> {
val itemsWithSubCats: MutableList<in Any?> = mutableListOf(items)
if (subCategories?.isNotEmpty() == true) {
itemsWithSubCats.add(ArrayList<Any>(subCategories!!))
}
return itemsWithSubCats.filterNotNull().toList()
}
這會導致 ClassCastException 如下:
java.lang.ClassCastException: java.util.ArrayList cannot be cast to ..RestaurantDetailsMenuItem
假設
items = arrayOf("a", "b")
subCategories = arrayOf("c", "d")
如果要實現 itemsWithSubCats = listOf("a", "b", "c", "d"),那么代碼應該是這樣的:
val itemsWithSubCats: MutableList<in Any?> = items.toMutableList()
if (subCategories?.isNotEmpty() == true) {
itemsWithSubCats.addAll(subCategories!!)
}
val list = itemsWithSubCats.filterNotNull().toList()
如果要實現 itemsWithSubCats = listOf(arrayOf("a", "b"), arrayOf("c", "d")),那么代碼應該是這樣的:
val itemsWithSubCats: MutableList<in Any?> = mutableListOf(items)
if (subCategories?.isNotEmpty() == true) {
itemsWithSubCats.add(subCategories!!)
}
val list = itemsWithSubCats.filterNotNull().toList()
在 Android Studio 中,行
itemsWithSubCats.add(ArrayList<Any>(subCategories!!))
顯然在我這邊給出錯誤。
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