Question

我有一个数据类报表

data class Report(var id: Int? = null, var user_name: String? = null)

我有一份报告清单。例如：

val reports = listOf(
Report(1, "Mike"),
Report(2, "John"),
Report(3, "Ann"),
Report(4, "Mike"),
Report(5, "Bob"),
Report(6, "Carl"),
Report(7, "Donald"),
Report(8, "John"),
Report(9, "Ann"),
Report(10, "Bob"))

如何使用RxJava将此报告列表转换为{_1}}，将由user_name进行处理？ id需要的最终变体是这样的：

List<List<Reports>>

Answer 1

您不需要使用RxJava。 Kotlin就足够了：

val grouped_map = reports.groupBy { it.user_name }
//{Mike=[Report(id=1, user_name=Mike), Report(id=4, user_name=Mike)], John=[Report(id=2, user_name=John), Report(id=8, user_name=John)], Ann=[Report(id=3, user_name=Ann), Report(id=9, user_name=Ann)], Bob=[Report(id=5, user_name=Bob), Report(id=10, user_name=Bob)], Carl=[Report(id=6, user_name=Carl)], Donald=[Report(id=7, user_name=Donald)]}

val reports_grouped_by_user_name = reports.groupBy { it.user_name }.values
//[[Report(id=1, user_name=Mike), Report(id=4, user_name=Mike)], [Report(id=2, user_name=John), Report(id=8, user_name=John)], [Report(id=3, user_name=Ann), Report(id=9, user_name=Ann)], [Report(id=5, user_name=Bob), Report(id=10, user_name=Bob)], [Report(id=6, user_name=Carl)], [Report(id=7, user_name=Donald)]]

RxJava Android列表到使用GroupBy的列表列表

1 个答案: