android - 在基于测验的应用程序中具有嵌套 setOnClickListener 的 RecyclerView
问题描述
我对基于测验的应用程序的基本功能的实现有疑问。简而言之,我在 an 中有“问题”和“答案” ArrayList<Question>
(每个Question
都有自己的ArrayList<Answer>
,在本示例中为3 个),用于RecyclerView
在 MVVM 管理的片段中填充 a 的适配器。
这是我的onBindViewHolder
功能:
...
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
...
val curQuest = myDataset[position]
val shuffledAnswers = curQuest.answers
holder.ans1.text = shuffledAnswers[0].answer_text
holder.ans1.setOnClickListener {
it.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
holder.ans2.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans3.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
}
holder.ans2.text = shuffledAnswers[1].answer_text
holder.ans2.setOnClickListener {
it.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
holder.ans1.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans3.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
}
holder.ans3.text = shuffledAnswers[2].answer_text
holder.ans3.setOnClickListener {
it.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
holder.ans2.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans1.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
}
}
一切正常,但选择了答案:如果我选择第一个问题的答案 ( ),列表中的N+0元素myDataset[0]
的视图也会发生变化,其中N是由RecyclerView
在加载的第 N个RecyclerView
元素之后,如何在不传播的情况下为每个子元素设置正确的属性?onBindViewHolder
它可以修复还是我必须改变实现方式?
编辑:我刚刚尝试了一个替代方案,但结果相同,使用界面:
QuizAdapter.kt
...
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
...
val curQuest = myDataset[position]
val shuffledAnswers = curQuest.answers
holder.ans1.text = shuffledAnswers[0].answer_text
holder.ans1.setOnClickListener {
mCallback.onClick(shuffledAnswers[0],position,it,holder.ans2,holder.ans3)
}
holder.ans2.text = shuffledAnswers[1].answer_text
holder.ans2.setOnClickListener {
mCallback.onClick(shuffledAnswers[1],position,it,holder.ans1,holder.ans3)
}
holder.ans3.text = shuffledAnswers[2].answer_text
holder.ans3.setOnClickListener {
mCallback.onClick(shuffledAnswers[2],position,it,holder.ans2,holder.ans1)
}
interface OnItemClickListener{
fun onClick(answerSelected: Answer?, questPosition: Int, selectedItemView: View, firstItemView: View, secondItemView: View)
}
QuizFragment.kt
...
mAdapter = QuizAdapter(this)
listQuestions.apply {
setHasFixedSize(true)
layoutManager = LinearLayoutManager(activity)
adapter = mAdapter
itemAnimator = DefaultItemAnimator()
}
mAdapter.setOnItemClickListener(object : QuizAdapter.OnItemClickListener{
override fun onClick(answerSelected: Answer?,
questPosition: Int,
selectedItemView: View,
firstItemView: View,
secondItemView: View) {
Snackbar.make(selectedItemView, "Your answer for $questPosition is ${answerSelected!!.isCorrect}.",
Snackbar.LENGTH_SHORT)
.setAction("Action", null).show()
selectedItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.selected_ans_quiz)
firstItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.default_ans_quiz)
secondItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.default_ans_quiz)
quizViewModel.chosenAnswers[questPosition] = answerSelected
}
})
fab_endQuiz.setOnClickListener { view ->
Snackbar.make(view, quizViewModel.chosenAnswers.toString(), Snackbar.LENGTH_LONG)
.setAction("Action", null).show()
//parentFragment?.findNavController()?.navigate(R.id.action_quizFragment_to_nav_home)
}
如您所见,使用 FAB,我可以测试所选答案的正确性,看起来还可以,地图充满了用户的选择,即使选择发生了变化(代表问题的地图位置已正确修改) . 但是背景颜色仍然混合在不同的位置(当前在 RecyclerView 中可见的位置加上前面的其他位置),如前所述。
解决方案
如果它有用,我找到了解决方案。我向类添加了一个布尔值,Answer
以便RecyclerView
必须检查在 xml 中构建其列表时是否与我之前所做的混合
QuizAdapter.kt
...
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
...
val curQuest = myDataset[position]
val shuffledAnswers = curQuest.answers
holder.ans1.text = shuffledAnswers[0].answer_text
if(shuffledAnswers[0].isSelected)
holder.ans1.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
else
holder.ans1.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans1.setOnClickListener {
shuffledAnswers[0].isSelected = true
shuffledAnswers[1].isSelected = false
shuffledAnswers[2].isSelected = false
mCallback.onClick(shuffledAnswers[0],position,it,holder.ans2,holder.ans3)
}
holder.ans2.text = shuffledAnswers[1].answer_text
if(shuffledAnswers[1].isSelected)
holder.ans2.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
else
holder.ans2.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans2.setOnClickListener {
shuffledAnswers[0].isSelected = false
shuffledAnswers[1].isSelected = true
shuffledAnswers[2].isSelected = false
mCallback.onClick(shuffledAnswers[1],position,it,holder.ans1,holder.ans3)
}
holder.ans3.text = shuffledAnswers[2].answer_text
if(shuffledAnswers[2].isSelected)
holder.ans3.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.selected_ans_quiz)
else
holder.ans3.background = ContextCompat.getDrawable(parentFragment.requireContext(),R.drawable.default_ans_quiz)
holder.ans3.setOnClickListener {
shuffledAnswers[0].isSelected = false
shuffledAnswers[1].isSelected = false
shuffledAnswers[2].isSelected = true
mCallback.onClick(shuffledAnswers[2],position,it,holder.ans1,holder.ans2)
}
}
interface OnItemClickListener{
fun onClick(answerSelected: Answer?, questPosition: Int, selectedItemView: View, firstItemView: View, secondItemView: View)
}
QuizFragment.kt
mAdapter.setOnItemClickListener(object : QuizAdapter.OnItemClickListener{
override fun onClick(answerSelected: Answer?,
questPosition: Int,
selectedItemView: View,
firstItemView: View,
secondItemView: View) {
selectedItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.selected_ans_quiz)
firstItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.default_ans_quiz)
secondItemView.background = ContextCompat.getDrawable(requireContext(),R.drawable.default_ans_quiz)
quizViewModel.chosenAnswers[questPosition] = answerSelected
}
})
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