通知 onSwiped 方法列表已在 mainActivity 中排序

Question

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....以及名称、大小等排序功能。

现在当我根据名称对列表进行排序时 onswipe viewholder ...不刷新

Suppose in a list ...at index[1]...gallery app is there, after sorting this goes to index[10] now the problem is onSwipe method think gallery is at index[1], but actually it is displayed on index[10] in recyclerView ..

这里出现的问题是当我在索引[1]处滑动时它执行图库的卸载对话框但它显示在[10]

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,
    viewHolder: RecyclerView.ViewHolder,
    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, recyclerView, viewHolder, dX, dY, actionState, 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()
  }

Answer 1

我在您的代码中看到一个问题：您正在使用 applicationList 在 onSwiped 中获取刷过的项目但在排序后，您将另一个列表放入适配器。有两种方法可以解决这个问题

从适配器获取刷卡项
或使用 sortBy() 而不是 sortedBy() 来排序列表

将代码段修改为

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
    }

通知 onSwiped 方法列表已在 mainActivity 中排序

notify onSwiped method that list is sorted in mainActivity

android

swipe

kotlin

android-recyclerview

itemtouchhelper