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[英]How to move the card view rest to the next card view in recyclerView in android
[英]How to redraw RecyclerView's card view on onRestart()?
我做了一個做筆記的應用程序,它可以執行基本的筆記動作(CRUD)。 問題是,每當用戶從第二個活動中刪除/創建或更新便箋時,主要活動(持有回收者視圖)都不會反映出任何更改。
僅在重新啟動應用程序,屏幕方向更改以及關閉和再次打開手機屏幕時反映更改。 我已經嘗試了stackoverflow的所有其他解決方案,但沒有任何效果。 我仍然必須重新啟動應用程序才能看到更改。 我還不了解任何實時數據,RxJava或任何其他高級體系結構,因為我仍然是初學者
問題是,從第二次活動返回后,如何在回收者視圖中重置名片視圖?
主要活動
class MainActivity : AppCompatActivity() {
var dbHandler: PediaDatabase? = null
var adapter: PediaAdapter? = null
var layoutManager: RecyclerView.LayoutManager? = null
var list: ArrayList<UserNotes>? = ArrayList()
var listItems: ArrayList<UserNotes>? = ArrayList()
var myPrefs: SharedPreferences? = null
var first_run: Boolean = true
var isCreated: Boolean = false
var isUpdated: Boolean = false
var isDeleted: Boolean = false
val PREFS_NAME: String = "MYPREFS"
val REQUEST_CODE: Int = 1
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
showOneTimeMessage()
invalidateOptionsMenu()
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
{
window.navigationBarColor = Color.BLACK
}
}
override fun onResume() {
super.onResume()
if(adapter != null)
{
recyclerViewID.recycledViewPool.clear()
recyclerViewID.invalidate()
}
Toast.makeText(this, "ONSTART", Toast.LENGTH_SHORT).show()
dbHandler = PediaDatabase(this)
adapter = PediaAdapter(this, listItems!!)
layoutManager = LinearLayoutManager(this)
recyclerViewID.adapter = adapter
recyclerViewID.layoutManager = layoutManager
list = dbHandler!!.readAllNotes()
//listItems = ArrayList()
for(reader in list!!.iterator())
{
var note = UserNotes()
note.noteTitle = reader.noteTitle
note.noteText = reader.noteText
note.noteID = reader.noteID
note.noteDate = reader.noteDate
listItems!!.add(note)
}
adapter!!.notifyDataSetChanged()
if(dbHandler!!.totalNotes() == 0) {
recyclerViewID.visibility = View.GONE
}
else{
recyclerViewID.visibility = View.VISIBLE
showWhenEmptyID.visibility = View.GONE
}
recyclerViewID.hasFixedSize()
}
override fun onRestart() {
super.onRestart()
list!!.clear()
list = dbHandler!!.readAllNotes()
for(reader in list!!.iterator())
{
var note = UserNotes()
note.noteTitle = reader.noteTitle
note.noteText = reader.noteText
note.noteID = reader.noteID
note.noteDate = reader.noteDate
listItems!!.add(note)
adapter!!.notifyDataSetChanged()
}
if(isCreated)
{
val newIndex: Int = listItems!!.size + 1
listItems!!.add(newIndex,existingNote)
adapter!!.notifyItemInserted(newIndex)
}
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if(requestCode == REQUEST_CODE)
if(resultCode == Activity.RESULT_OK)
{
isCreated = data?.extras!!.getBoolean("isCreated")
}
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
menuInflater.inflate(R.menu.top_menu, menu)
val item = menu!!.findItem(R.id.delete_note_menu)
item.setVisible(false)
return true
}
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
if(item!!.itemId == R.id.add_note_menu){
isNewNote = true
startActivity(Intent(this, ReferenceActivity::class.java))
}
if(item!!.itemId == R.id.delete_note_menu)
{
Toast.makeText(this,"DELETED", Toast.LENGTH_SHORT).show()
}
return super.onOptionsItemSelected(item)
}
private fun showOneTimeMessage()
{
var data: SharedPreferences = getSharedPreferences(PREFS_NAME, 0)
if(data.contains("isShown"))
{
first_run = data.getBoolean("isShown", true)
}
Log.d("FIRST_RUN", first_run.toString())
if(first_run)
{
val oneTimeMsg = SweetAlertDialog(this)
oneTimeMsg.setTitleText("Hey there!")
oneTimeMsg.setContentText("Thank you for downloading! Please don`t forget to rate our app :)").show()
oneTimeMsg.setConfirmClickListener(object : SweetAlertDialog.OnSweetClickListener
{
override fun onClick(sweetAlertDialog: SweetAlertDialog?)
{
oneTimeMsg.dismissWithAnimation()
}
}).show()
myPrefs = getSharedPreferences(PREFS_NAME, 0)
var editor: SharedPreferences.Editor = (myPrefs as SharedPreferences).edit()
editor.putBoolean("isShown", false)
editor.commit()
}
}
適配器類
class PediaAdapter(private val context: Context,
private val noteslist: ArrayList<UserNotes>): RecyclerView.Adapter<PediaAdapter.ViewHolder>()
{
override fun onCreateViewHolder(p0: ViewGroup, p1: Int): ViewHolder
{
val view = LayoutInflater.from(context).inflate(R.layout.list_row,p0,false)
return ViewHolder(view, noteslist)
}
override fun getItemCount(): Int
{
return noteslist.size
}
override fun onBindViewHolder(p0: ViewHolder, p1: Int)
{
p0.bindItems(noteslist[p1])
}
inner class ViewHolder(itemView: View, list: ArrayList<UserNotes>): RecyclerView.ViewHolder(itemView), View.OnClickListener
{
private var noteTitle = itemView.findViewById(R.id.listTitleID) as TextView
private var noteText = itemView.findViewById(R.id.listTextID) as TextView
var mList = list
init
{
itemView.setOnClickListener(this)
}
fun bindItems(note: UserNotes)
{
//var id = note.noteID
noteTitle.text = note.noteTitle
noteText.text = note.noteText
}
override fun onClick(v: View?)
{
var mPosition: Int = adapterPosition //For forwarding position to ref activity
var note = mList[mPosition]
adapPos = adapterPosition
var cardID = Intent(itemView.context, ReferenceActivity::class.java)
cardID.putExtra("cardPosition", mPosition)
cardID.putExtra("cardID", note.noteID) //TODO THIS IS FETCHING NOTE_ID VALUES FROM DB
Toast.makeText(itemView.context, "card id = " + note.noteID, Toast.LENGTH_SHORT).show()
itemView.context.startActivity(cardID)
}
}
參考活動(第二)
class ReferenceActivity : AppCompatActivity() {
var dbHandler: PediaDatabase? = null
var note = UserNotes()
var noteExisted: Boolean = false
var cardAdapterPos: Int? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_reference)
getSupportActionBar()!!.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM)
getSupportActionBar()!!.setCustomView(R.layout.custom_toolbar)
val dateTxtView = findViewById<View>(resources.getIdentifier("action_bar_title", "id", packageName)) as TextView
overridePendingTransition(R.anim.slide_in, R.anim.slide_out)
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
window.navigationBarColor = Color.BLACK
dbHandler = PediaDatabase(this)
val data = intent
if(isNewNote != true/*isNewNote.extras.getBoolean("isNewNote") != true*/)
{
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN)
if(data != null)
{
noteExisted = true
this.cardAdapterPos = data.extras.getInt("cardPosition")
cardID = data.extras.getInt("cardID")
existingNote = dbHandler!!.readNote(cardID)
refTitleID.setText(existingNote.noteTitle, TextView.BufferType.EDITABLE)
refTextID.setText(existingNote.noteText, TextView.BufferType.EDITABLE)
dateTxtView.text = existingNote.noteDate.toString()
}
}else{
dateTxtView.text = "New note"
}
}
override fun onStop() {
super.onStop()
var title: String = refTitleID.text.toString().trim()
var text: String = refTextID.text.toString().trim()
if(existingNote.noteText == text && existingNote.noteTitle == title)
finish()
if(noteExisted)
{
if(TextUtils.isEmpty(title))
title = "No title"
existingNote.noteTitle = title
existingNote.noteText = text
existingNote.noteDate = System.currentTimeMillis().toString() //TODO TRY THIS
dbHandler!!.updateNote(existingNote)
var sharedPrefs = getSharedPreferences(PREFS_SHARE, Context.MODE_PRIVATE)
val share_editor: SharedPreferences.Editor = (sharedPrefs as SharedPreferences).edit()
share_editor.putBoolean("update", true).commit()
finish()
}
else
{
if(TextUtils.isEmpty(title) && TextUtils.isEmpty(text))
{
finish()
}
else
{
if(TextUtils.isEmpty(title))
title = "No title"
note.noteTitle = title
note.noteText = text
note.noteDate = System.currentTimeMillis().toString()
// note.noteID =
dbHandler!!.createNote(note)
val dataCreate = this.intent
dataCreate.putExtra("isCreated", true)
setResult(Activity.RESULT_OK, dataCreate)
finish()
}
}
}
override fun onCreateOptionsMenu(menu: Menu?): Boolean {
menuInflater.inflate(R.menu.top_menu, menu)
val addItem: MenuItem = menu!!.findItem(R.id.add_note_menu)
val delItem:MenuItem = menu.findItem(R.id.delete_note_menu)
addItem.setVisible(false)
delItem.setVisible(false)
if(noteExisted)
delItem.setVisible(true)
return true
}
override fun onOptionsItemSelected(item: MenuItem?): Boolean {
if(item!!.itemId == R.id.delete_note_menu)
{
val dialogMsg = SweetAlertDialog(this, SweetAlertDialog.WARNING_TYPE)
dialogMsg.setTitleText("Are you sure?")
dialogMsg.setContentText("You won`t be able to recover this note!")
dialogMsg.setConfirmText("Yes, delete it!")
dialogMsg.setConfirmClickListener(object: SweetAlertDialog.OnSweetClickListener {
override fun onClick(sweetAlertDialog: SweetAlertDialog?) {
dialogMsg.dismissWithAnimation()
dbHandler!!.deleteNote(cardID)
val successMsg = SweetAlertDialog(sweetAlertDialog!!.context, SweetAlertDialog.SUCCESS_TYPE)
successMsg.setTitleText("Note deleted!")
successMsg.setContentText("So long,note").show()
successMsg.setCancelable(false)
//TODO Disable 'OK' button on successMsg dialogbox
Handler().postDelayed({
successMsg.dismissWithAnimation()
finish()
}, 1200)
}
}).show()
}
return super.onOptionsItemSelected(item)
}
從第二個活動返回時,您可以致電
adapter.notifyDataSetChanged();
為了告訴RV的適配器重新創建所有viewHolders並重新綁定視圖。
但是,如果您知道已刪除/更新的項目的確切索引,那將是更好的選擇。 這樣,您可以致電:
adapter.notifyItemRemoved(position)
告知適配器刪除物品,或:
adapter.notifyItemChanged(position)
為了告訴適配器重新繪制(調用onBindViewHolder)特定項。
編輯:我看到您已經在調用這些方法,但是您永遠不會更新適配器持有的列表! 您正在活動中而不是適配器中更新列表。 因此,您應該做的是向適配器添加如下所示的方法:
fun updateResults(items: List<UserNotes>) {
noteslist = items
}
並將“ noteslist” val更改為var。 用新列表調用“ updateResults”后,調用
adapter.notifyDataSetChanged();
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