Android 如何访问RecyclerView位置
这里完全是初学者。似乎我在这里遗漏了一些非常基本的东西,所以任何关于它的资源或一个好的解释都将不胜感激 我用PagerSnapHelper添加了一个Recycler视图。我左右滑动,一切正常。现在,在我的activity_main.xml的文本视图中,我希望应用程序显示适配器的当前位置 最好的方法是什么 我尝试了两种方法,例如Android 如何访问RecyclerView位置,android,android-recyclerview,position,Android,Android Recyclerview,Position,这里完全是初学者。似乎我在这里遗漏了一些非常基本的东西,所以任何关于它的资源或一个好的解释都将不胜感激 我用PagerSnapHelper添加了一个Recycler视图。我左右滑动,一切正常。现在,在我的activity_main.xml的文本视图中,我希望应用程序显示适配器的当前位置 最好的方法是什么 我尝试了两种方法,例如val pozycja adaptera=recyclerView.layoutManager.findContainingItemView()或一些奇怪的getAdapt
val pozycja adaptera=recyclerView.layoutManager.findContainingItemView()
或一些奇怪的getAdapterPosition()实例
但我认为它们要么不适合这种场合,要么就是我用错了
请查看下面的代码:
class MainActivity : AppCompatActivity() {
@RequiresApi(Build.VERSION_CODES.O)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//Adding RecyclerView
val recyclerView = findViewById<RecyclerView>(R.id.recyclerview_id)
recyclerView.run {
layoutManager = LinearLayoutManager(
this@MainActivity,
LinearLayoutManager.HORIZONTAL,
false)
adapter = MyAdapter()
// This makes mood_layout snap to grid (full screen)
PagerSnapHelper().attachToRecyclerView(this)
}
//Accessing Recycler View position
val widokPozycji = findViewById<TextView>(R.id.textView_position)
val pozycjaAdaptera = recyclerView.layoutManager.findContainingItemView()
//Adding AlertDialog to add comments
btn_addNote.setOnClickListener {
//Setting Inflater to inflate Dialog with comment_edit_text.xml layout
val dialogLayout = LayoutInflater.from(this).inflate(R.layout.comment_edit_text, null)
val builder = AlertDialog.Builder(this)
.setView(dialogLayout)
.show()
//Adding Shared Preferences to save a comment on confirmCommentButton button
builder.confirmCommentButton.setOnClickListener {
//creating instance of Shared Preferences
val pref = getSharedPreferences("commentSharedPreferences", Context.MODE_PRIVATE)
val editor = pref.edit()
//ACCESSING COMMENT WRITTEN BY USER in AlertDialog.Builder - val builder
val insertedName = builder.editTextComment.text.toString()
//Saving shared Preferences
editor.apply {
putString("STRING_KEY", insertedName)
apply()
}
// Toast to confirm saved data
Toast.makeText(this, "Comment Saved", Toast.LENGTH_SHORT).show()
//close Dialog on CONFIRM button click
builder.dismiss()
}
//CANCEL button that closes Dialog on click
builder.cancelCommentButton.setOnClickListener{
builder.dismiss()
}
builder.setOnDismissListener {
}
}
}
//HISTORY button taking user to HistoryActivity on click
fun history(view: View) {
// New Activity to open HistoryActivity
var historyActivity: Intent = Intent(applicationContext, HistoryActivity::class.java)
startActivity(historyActivity)
}
}
class MainActivity:AppCompatActivity(){
@RequiresApi(Build.VERSION\u code.O)
重写创建时的乐趣(savedInstanceState:Bundle?){
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//添加RecyclerView
val recyclerView=findviewbyd(R.id.recyclerView\u id)
循环视图{
layoutManager=LinearLayoutManager(
this@MainActivity,
LinearLayoutManager.HORIZONTAL,
(错误)
adapter=MyAdapter()
//这使mood_布局捕捉到网格(全屏)
PagerSnapHelper().attachToRecyclerView(此)
}
//访问回收器视图位置
val widokPozycji=findViewById(R.id.textView\u位置)
val pozycjaAdaptera=recyclerView.layoutManager.findContainingItemView()
//添加AlertDialog以添加注释
btn_addNote.setOnClickListener{
//将充气器设置为使用comment_edit_text.xml布局充气对话框
val dialogLayout=LayoutInflater.from(this).充气(R.layout.comment\u edit\u text,null)
val builder=AlertDialog.builder(此)
.setView(对话框布局)
.show()
//添加共享首选项以在confirmCommentButton按钮上保存注释
builder.confirmCommentButton.setOnClickListener{
//创建共享首选项的实例
val pref=getSharedReferences(“CommentSharedReferences”,Context.MODE\u PRIVATE)
val editor=pref.edit()
//访问用户在AlertDialog.Builder-val Builder中编写的注释
val insertedName=builder.editTextComment.text.toString()
//保存共享首选项
editor.apply{
putString(“字符串_键”,insertedName)
应用()
}
//Toast以确认保存的数据
Toast.makeText(此“注释已保存”,Toast.LENGTH\u SHORT.show())
//单击“确认”按钮关闭对话框
解雇
}
//单击关闭对话框的取消按钮
builder.cancelCommentButton.setOnClickListener{
解雇
}
builder.setOnDismissListener{
}
}
}
//单击“历史记录”按钮将用户带到历史活动
趣味历史(查看:查看){
//打开HistoryActivity的新活动
var historyActivity:Intent=Intent(applicationContext,historyActivity::class.java)
星触觉(历史活动)
}
}
适配器:
class MyViewHolder(val view : View):RecyclerView.ViewHolder(view)
class MyAdapter : RecyclerView.Adapter<MyViewHolder>(){
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val moodInflater = layoutInflater.inflate(R.layout.mood_layout, parent, false)
return MyViewHolder(moodInflater)
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
val context = holder.view.context
val emoji = holder.view.emoji_img
val background = holder.view.moodLayout_id
val moodSelected = position
when(moodSelected){
0 -> {emoji.setImageResource(R.drawable.smiley_super_happy)
background.setBackgroundColor(context.resources.getColor(R.color.banana_yellow))
}
1 -> {emoji.setImageResource(R.drawable.smiley_happy)
background.setBackgroundColor(context.resources.getColor(R.color.light_sage))
}
2 -> {emoji.setImageResource(R.drawable.smiley_normal)
background.setBackgroundColor(context.resources.getColor(R.color.cornflower_blue_65))
}
3 -> {emoji.setImageResource(R.drawable.smiley_disappointed)
background.setBackgroundColor(context.resources.getColor(R.color.warm_grey))
}
4 -> {emoji.setImageResource(R.drawable.smiley_sad)
background.setBackgroundColor(context.resources.getColor(R.color.faded_red))
}
}
}
override fun getItemCount(): Int {
return 5
}
}
类MyViewHolder(val视图:视图):RecyclerView.ViewHolder(视图)
类MyAdapter:RecyclerView.Adapter(){
重写CreateViewHolder(父级:ViewGroup,viewType:Int):MyViewHolder{
val layoutInflater=layoutInflater.from(parent.context)
val moodInflater=layoutInflater.flate(R.layout.mood_布局,父级,false)
返回MyViewHolder(moodInflater)
}
覆盖onBindViewHolder(holder:MyViewHolder,位置:Int){
val context=holder.view.context
val emoji=holder.view.emoji\u img
val background=holder.view.moodLayout\u id
val moodSelected=位置
何时(moodSelected){
0->{emoji.setImageResource(R.drawable.smiley\u super\u happy)
backgroundColor(context.resources.getColor(R.color.banana_yellow))
}
1->{emoji.setImageResource(R.drawable.smiley_happy)
backgroundColor(context.resources.getColor(R.color.light_-sage))
}
2->{emoji.setImageResource(R.drawable.smiley_normal)
backgroundColor(context.resources.getColor(R.color.cornflower\u blue\u 65))
}
3->{emoji.setImageResource(R.drawable.smiley_)
backgroundColor(context.resources.getColor(R.color.warm\u grey))
}
4->{emoji.setImageResource(R.drawable.smiley_sad)
backgroundColor(context.resources.getColor(R.color.flated_red))
}
}
}
重写getItemCount():Int{
返回5
}
}
好的,所以我使用共享首选项来存储位置,并能够从其他活动中访问它。我把它们放在文件夹里。代码如下所示:
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
val context = holder.view.context
val sharedPref = holder.view.context.getSharedPreferences("position", MODE_PRIVATE)
val editor = sharedPref.edit()
editor.putInt("POSITION_KEY", position)
editor.apply()