Kotlin，recyclerview适配器如何按DESC对查询结果进行排序 [英] Kotlin, recyclerview adapter how to sort results from query by DESC

问题描述

它是我的代码.我做错了什么?我想在recyclerview中显示降序结果.

its my code. What i doing wrong? I would like to display descending results in recyclerview.

TableInfo.TABLE_COLUMN_MESSAGE = "points"

override fun onBindViewHolder(p0: MojViewHolder, p1: Int) {

    val wynikwynik = p0.view.textViewWynik
    val wynikuser = p0.view.textView_user


    val cursor = db.query(TableInfo.TABLE_NAME, null, BaseColumns._ID + "=?", arrayOf(p0.adapterPosition.plus(1).toString()), null, null, TableInfo.TABLE_COLUMN_MESSAGE +" DESC")



    if (cursor.moveToFirst()){

        wynikwynik.text=cursor.getString(1).toString()
        wynikuser.text=cursor.getString(2).toString()

    }


    cursor.close()

}

推荐答案

首先，您应该分离业务逻辑的视图，我想说您不应该在recyclerView中执行db请求，最好的方法是在recyclerView中传递一组数据，这些数据就是recyclerView lList的信息，如果您在ViewHolder中发出db请求，那么您将在List的每一行中发出请求，这是一个问题.

First of all you should separate the view of your Business Logic, I want to say you shouldn't do a db request within of recyclerView, the best way is pass an val of data in your recyclerView, this data is the info for your recyclerView lList, if you make a db request inside of your ViewHolder you are making a request in every row of your List and this is a problem.

检查以下有关回收者视图工作的信息: https://developer.android.com/guide/topics/ui/layout/recyclerview

Check this information of the work of a recycler view: https://developer.android.com/guide/topics/ui/layout/recyclerview

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