将其值设置为“”后无法过滤 AutoCompleteTextView

Question

我的 Android 应用程序中有一个 AutoCompleteTextView，我为它的布局和过滤器制作了一个自定义适配器。

问题是在我取消我在 AutoCompleteTextView 中写入的所有内容之前，过滤器工作正常只有当我清空输入值时。

默认情况下，当输入为空时，我会显示用户可以选择的整个项目列表。

这是我的自定义适配器：

class FornitoriAdapter(context: Context, fornitori: MutableList<Fornitori> = mutableListOf(), resource: Int) :
    ArrayAdapter<Fornitori>(context, resource), Filterable {

    private var filteredList: MutableList<Fornitori> = mutableListOf()

    init {
        filteredList = fornitori.toMutableList()
    }

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
        val row: View
        val holder: ViewHolder

        if (convertView == null) {
            val inflater = LayoutInflater.from(context)
            row = inflater.inflate(R.layout.list_item, parent, false)
            holder = ViewHolder(row)
            row.tag = holder
        } else {
            row = convertView
            holder = row.tag as ViewHolder
        }

        val fornitore: Fornitori = filteredList[position]

        holder.descrText.text = fornitore.desc
        holder.codeText.text = fornitore.cod

        return row
    }

    override fun getCount(): Int {
        return filteredList.size
    }

    override fun getItem(position: Int): Fornitori {
        return filteredList[position]
    }

    private class ViewHolder constructor(row: View) {
        val descrText: TextView = row.findViewById(R.id.description)
        val codeText: TextView = row.findViewById(R.id.code)
    }

    override fun getFilter(): Filter {
        return customFilter
    }

    private val customFilter = object : Filter() {
        override fun convertResultToString(resultValue: Any?): CharSequence {
            return (resultValue as Fornitori).desc
        }

        override fun performFiltering(constraint: CharSequence?): FilterResults {
            return if (constraint != null) {
                filteredList.clear()
                fornitori.forEach { // HERE FORNITORI IF I EMPTY THE INPUT BECOME LENGTH 0
                    if (it.cod.equals(constraint.toString(), ignoreCase = true) || it.desc.toLowerCase(
                            Locale.ROOT
                        ).startsWith(
                            constraint.toString().toLowerCase(
                                Locale.ROOT
                            )
                        )
                    ) {
                        filteredList.add(it)
                    }
                }
                val filterResults = FilterResults()
                filterResults.values = filteredList
                filterResults.count = filteredList.size
                filterResults
            }else {
                filteredList.clear()
                filteredList = fornitori
                val filterResults = FilterResults()
                filterResults.values = filteredList
                filterResults.count = filteredList.size
                filterResults
            }
        }

        override fun publishResults(constraint: CharSequence?, filterResults: FilterResults) {
            val filterList = filterResults.values as? MutableList<*>
            if (filterResults.count > 0) {
                filterList?.forEach {
                    add(it as Fornitori)
                }.also {
                    notifyDataSetChanged()
                }
            }
        }

    }

}

因此，一旦我开始过滤或选择显示的项目之一，一切正常，但一旦我取消输入值，我就无法从自动完成中获取任何值，因为 fornitori 设置为 null，就像它的列表一样已被清除但我实际上只清除了过滤后的列表..

Answer 1

问题出在你第一次设置

filteredList = fornitori

然后调用

filteredList.clear()

因为您已将 filteredList 设置为引用 fornitori，然后通过清除 filteredList 您也清除了 fornitori。因此，不只是重新分配变量，您实际上应该将 fornitori 复制到 filteredList.

Kotlin 其实并没有列表的复制功能，不过我觉得最清楚的是：

filteredList.clear()
filteredList.addAll(fornitori)

将其值设置为“”后无法过滤 AutoCompleteTextView

Unable to filter AutoCompleteTextView after settings it's value to ""

android

kotlin

android-filterable