通知onSwiped方法列表已在mainActivity中排序

问题描述

我正在使用recyclerView来显示设备中安装的应用程序列表，我实现了onSwipe方法来执行卸载....以及诸如名称，大小等排序功能。

现在，当我根据名称在滑动查看器上对列表进行排序时...不刷新

假设在列表中……在索引[1] ...之后，有画廊应用程序 排序到索引[10]现在问题是onSwipe方法认为 图库位于索引[1]，但实际上它显示在索引[10]中 recyclerView ..

问题发生在这里是当我在索引[1]上滑动时，它执行图库的卸载对话框，但显示在[10]上

---

如何通知onSwiped方法列表已排序，并且每个项目都更改其索引

---

MainActivity.kt

class MainActivity : AppCompatActivity() {

lateinit var adapter: Adapter  // create adapter instance
lateinit var applicationList:MutableList<AppData>

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)

    applicationList = getApps(installedApps()) // initialize applicationList variable
    recyclerView.layoutManager = LinearLayoutManager(this)
    adapter = Adapter(applicationList) // initialize adapter variable
    recyclerView.adapter = adapter // pass adapter to recyclerView

   sortList()

          // I create sepearate abstract class SwipeToDeleteCallback and call here

    val swipeHandler = object : SwipeToDeleteCallback(this) {
        override fun onSwiped(viewHolder: RecyclerView.ViewHolder,direction: Int) {
            currentItem = viewHolder.adapterPosition
            val packageName =
                applicationList[currentItem].packageName // get packageName from position
            val appCategory = applicationList[currentItem].category

                uninstall() // call uninstall function
        }
        
    }
    val itemTouchHelper = ItemTouchHelper(swipeHandler)
    itemTouchHelper.attachToRecyclerView(recyclerView) // attach onSwipe to recyclerView

}

fun uninstall(){
    // perform uninstall 
}

private fun installedApps(): MutableList<ResolveInfo> {
  // get installed apps
}

fun sortList() { 
    Sort_List.setOnClickListener {
        val popUp = PopupMenu(this,Sort_List)
        popUp.menuInflater.inflate(R.menu.sort_menu,popUp.menu)

        popUp.setOnMenuItemClickListener { myItem ->
            when (myItem.itemId) {
                R.id.Name_ASC -> {
                    
                    val sortedList =  applicationList.sortedBy { it.name }
                    adapter.update(sortedList)
                }
                R.id.Name_DES -> {
                    val sortedList =  applicationList.sortedByDescending { it.name }
                    adapter.update(sortedList)
                }
              }
            true
        }
        popUp.show()
    }
}


private fun getApps(List: MutableList<ResolveInfo>): MutableList<AppData> {

    // fetch all apps and return list
}

SwipeToDeleteCallback.kt

abstract class SwipeToDeleteCallback(context: Context) : ItemTouchHelper.SimpleCallback(0,ItemTouchHelper.LEFT) {

private val deleteIcon = ContextCompat.getDrawable(context,R.drawable.ic_delete_white)
private val intrinsicWidth = deleteIcon?.intrinsicWidth
private val intrinsicHeight = deleteIcon?.intrinsicHeight
private val background = ColorDrawable()
private val backgroundColor = Color.parseColor("#f44336")
private val clearPaint = Paint().apply { xfermode = PorterDuffXfermode(PorterDuff.Mode.CLEAR) }


override fun getMovementFlags(
    recyclerView: RecyclerView,viewHolder: RecyclerView.ViewHolder
): Int {
    return super.getMovementFlags(recyclerView,viewHolder)
}

override fun onMove(
    recyclerView: RecyclerView,viewHolder: RecyclerView.ViewHolder,target: RecyclerView.ViewHolder
): Boolean {
    return false
}

override fun onChildDraw(
    c: Canvas,recyclerView: RecyclerView,dX: Float,dY: Float,actionState: Int,isCurrentlyActive: Boolean
) {
    val itemView = viewHolder.itemView
    val itemHeight = itemView.bottom - itemView.top
    val isCanceled = dX == 0f && !isCurrentlyActive

    if (isCanceled){
        clearCanvas(c,itemView.right + dX,itemView.top.toFloat(),itemView.right.toFloat(),itemView.bottom.toFloat())
        super.onChildDraw(c,recyclerView,viewHolder,dX,dY,actionState,isCurrentlyActive)
    }

    // Draw the red delete button
   
    //Calculate position of delete icon
   
    // Draw the delete icon
    
    super.onChildDraw(c,isCurrentlyActive)
}

private fun clearCanvas(c: Canvas?,left: Float,top: Float,right: Float,bottom: Float) {
    c?.drawRect(left,top,right,bottom,clearPaint)
}

Adapter.kt

class Adapter(private var listOfApps: MutableList<AppData>) :
RecyclerView.Adapter<Adapter.ViewHolder>() {

class ViewHolder(appView: View) : RecyclerView.ViewHolder(appView) {

    // call elements from list_apps.xml
    val icon: ImageView = appView.App_icon
    val name: TextView = appView.App_name
    val size: TextView = appView.App_size
}

override fun onCreateViewHolder(parent: ViewGroup,viewType: Int): ViewHolder {
    val view = LayoutInflater.from(parent.context).inflate(
        R.layout.list_apps,parent,false
    )
    return ViewHolder(view)
}

override fun getItemCount() = listOfApps.size

override fun onBindViewHolder(holder: ViewHolder,position: Int) {

    val currentItem = listOfApps[position]
    holder.icon.setImageDrawable(currentItem.icon) 
    holder.name.text = currentItem.name
    holder.size.text = currentItem.size
    
}
fun update(newList: MutableList<AppData>){
    listOfApps = newList
    notifyDataSetChanged()
  }

解决方法

我在您的代码中看到一个问题： 您正在使用 applicationList 在 onSwiped 中获取滑动项 但排序后，您将另一个列表放入适配器。 有两种方法可以解决此问题

1. 从适配器获取刷卡项目
2. 或使用 sortBy （）代替 sortedBy （）进行排序

修改片段到

popUp.setOnMenuItemClickListener { myItem ->
        when (myItem.itemId) {
            R.id.Name_ASC -> {
                
                applicationList.sortBy{ it.name }
                adapter.notifyDataSetChanged()
            }
            R.id.Name_DES -> {
                applicationList.sortByDescending{ it.name }
                adapter.notifyDataSetChanged()
            }
          }
        true
    }