为什么旋转器函数不能选择项目?

Question

我遇到了一个问题，我的旋转器无法显示页面中选择的项目。但是对于"全部"的选择，它可以正常显示所有的项目，但是当我在spinner中单击其中一个选择时，无论选择名称是否与作业名称匹配，它都不会显示任何内容。有人能帮帮我吗?

override fun onResume() {
        super.onResume()
        val places=resources.getStringArray(R.array.place)
        val arrayAdapter=ArrayAdapter(requireContext(),R.layout.dropdown_item,places)
        val jobs=resources.getStringArray(R.array.job)
        val arrayAdapter2=ArrayAdapter(requireContext(),R.layout.dropdown_item,jobs)
        binding.spinnerPlace.setAdapter(arrayAdapter)
        binding.spinnerJob.setAdapter(arrayAdapter2)
        spinner_job.onItemSelectedListener=object : AdapterView.OnItemSelectedListener{
            override fun onItemSelected(
                parent: AdapterView<*>?,
                view: View?,
                position: Int,
                id: Long
            ) {
                if (parent != null) {
                    if(parent.getItemAtPosition(position)=="All"){
                        tempArrayList.addAll(newArrayList)
                        val adapter=Search_Page_Adapter(requireContext(),tempArrayList)
                        newRecyclerView.adapter=adapter
                        newRecyclerView.layoutManager=LinearLayoutManager(requireContext())
                    }
                    else{
                        tempArrayList.clear()
                        val item=parent.getItemAtPosition(position).toString()
                       Toast.makeText(parent.context,"Selected:$item",Toast.LENGTH_SHORT).show()
                        if(item.isNotEmpty()){
                            newArrayList.forEach{
                                if(it.jobname?.lowercase(Locale.getDefault())!!.contains(item)){
                                    tempArrayList.add(it)
                                }
                                val adapter=Search_Page_Adapter(requireContext(),tempArrayList)
                                newRecyclerView.adapter=adapter
                                newRecyclerView.layoutManager=LinearLayoutManager(requireContext())
                            }
                        }else{
                            tempArrayList.clear()
                            tempArrayList.addAll(newArrayList)
                            newRecyclerView.adapter!!.notifyDataSetChanged()
                        }
                    }
                }
            }
            override fun onNothingSelected(parent: AdapterView<*>?) {
                TODO("Not yet implemented")
            }
        }
        
    }

Answer 1

尝试更改您的onItemSelectedListener逻辑:

        spinner_job.onItemSelectedListener=object : AdapterView.OnItemSelectedListener{
            override fun onItemSelected(
                parent: AdapterView<*>?,
                view: View?,
                position: Int,
                id: Long
            ) {
                val item = parent.getItemAtPosition(position).toString()
                if(item == "All") {
                    // `All` selected
                    tempArrayList.addAll(newArrayList)
                    val adapter=Search_Page_Adapter(requireContext(),tempArrayList)
                    newRecyclerView.adapter=adapter
                    newRecyclerView.layoutManager=LinearLayoutManager(requireContext())
                }
                else {
                    // Others selected
                    Toast.makeText(parent.context,"Selected:$item",Toast.LENGTH_SHORT).show()
                    if(item.isNotEmpty()){
                        newArrayList.forEach{
                            if(it.jobname?.lowercase(Locale.getDefault())!!.contains(item)){
                                tempArrayList.add(it)
                            }
                            val adapter=Search_Page_Adapter(requireContext(),tempArrayList)
                            newRecyclerView.adapter=adapter
                            newRecyclerView.layoutManager=LinearLayoutManager(requireContext())
                        }
                    } else {
                        tempArrayList.clear()
                        tempArrayList.addAll(newArrayList)
                        newRecyclerView.adapter!!.notifyDataSetChanged()
                    }
                }
            }
            override fun onNothingSelected(parent: AdapterView<*>?) {
                TODO("Not yet implemented")
            }