kotlin

Question

实际上我想按以下方式对我的列表进行排序：我有一个像这样的 mutableList

noteList = mutableListOf<NoteDataHolder>().apply {
        notes.forEach {
            add(NoteDataHolder(it))
        }
}

假设 NoteDataHolder 有 Id，我想按此 Id

对我的列表进行排序

我的列表是这样的：[ {id=1}, {id=2}, {id=3}, {id=4} ]

当我像这样过滤列表时：noteList.filter { it.note?.bookId == 4 }

我只收到[ {id=4} ]

最后，我想像这样 item4 之后得到所有项目 [ {id=4}, {id=1}, {id=2}, {id=3} ]

Answer 1

看来您需要这样的东西：

fun reorderItems(input: List<NoteDataHolder>, predicate: (NoteDataHolder) -> Boolean): List<NoteDataHolder>{
    val matched = input.filter(predicate)
    val unmatched = input.filterNot(predicate)

    return matched + unmatched
}

使用：

noteList = reorderItems (noteList!!) {it.note?.bookId == 4}

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kotlin - filter MutableList with append other items in the end of list

android

mutablelist