我正在读取存储在Room数据库中的联系人并将其显示在recyclerView中。同样，使用nbested recyclerView。但是花了很多时间在这我不明白为什么回收视图不加载…也不显示任何Toast消息(它们存在于活动中)。我在下面分享了活动/适配器和布局代码…有什么想法会有帮助的…
活动private lateinit var progressBar: ProgressDialog
var firebaseUser: FirebaseUser? = null //the used id of the user using the app
var managecontactsadapter: ManageContactsAdapter? = null
var reference: DatabaseReference? = null
var rvCRM: RecyclerView? = null
private val _contsCRMLiveData = MutableLiveData<ArrayList<Contact>>()
private val crmContactsLiveData: LiveData<ArrayList<Contact>> = _contsCRMLiveData
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_manage_contacts)
setSupportActionBar(toolbar_contacts)
supportActionBar!!.title = ""
supportActionBar!!.setDisplayHomeAsUpEnabled(true)
//Progress Bar
progressBar = ProgressDialog(this)
progressBar.setCancelable(false)
progressBar.setMessage("Loading...")
rvCRM = findViewById(R.id.rvCRM)
rvCRM!!.setHasFixedSize(true)
rvCRM!!.layoutManager = LinearLayoutManager(this)
displayContacts()
crmContactsLiveData.observe(this, Observer {
rvCRM!!.adapter = managecontactsadapter
})
Toast.makeText(this, "Adapter Called.", Toast.LENGTH_SHORT).show()
contact_fab.setOnClickListener {
val intent = Intent(this, EditContact::class.java)
intent.putExtra("Edit", false)
this.startActivity(intent)
}
contSort.setOnClickListener {
}
contFilter.setOnClickListener {
}
}
//Top Right Menu
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu; this adds items to the action bar if it is present.
menuInflater.inflate(R.menu.menu_main, menu)
return true
}
//Top Right Menu Options Selected Actions
override fun onOptionsItemSelected(item: MenuItem): Boolean {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
when (item.itemId) {
R.id.action_settings -> {
val intent = Intent(this@ManageContacts, SettingsActivity::class.java)
startActivity(intent)
return true
}
R.id.Logout -> {
//Google Sign Out
progressBar.show()
val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestIdToken(getString(R.string.default_web_client_id))
.requestEmail()
.build()
val mGoogleSignInClient = GoogleSignIn.getClient(this, gso)
mGoogleSignInClient.revokeAccess()
.addOnCompleteListener(this) {
mGoogleSignInClient.signOut()
.addOnCompleteListener(this) { progressBar.dismiss();finish() }
}
//Firebase sign Out
FirebaseAuth.getInstance().signOut()
val intent = Intent(this@ManageContacts, IntroScreensHome::class.java)
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK)
startActivity(intent)
finish()
return true
}
}
return false
}
private fun displayContacts() {
val mupdateList = ArrayList<Contact>()
lateinit var contact : List<Contact>
val db = AppDatabase.getDatabase(this)
db.contactsDao().getcrmContacts().observe(this, Observer {
contact = it
mupdateList.clear()
for (i in contact) {
mupdateList.add(i)
}
})
val size = mupdateList.size
Toast.makeText(this, "Display Called.", Toast.LENGTH_SHORT).show()
managecontactsadapter = ManageContactsAdapter(this, mupdateList)
rvCRM!!.adapter = managecontactsadapter
}
}
class ManageContactsAdapter(
mContext: Context,
mupdateList: ArrayList<Contact>
) : RecyclerView.Adapter<ManageContactsAdapter.MyViewHolder?>() {
private val layoutInflater = mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
private val mContext: Context
private val mupdateList: List<Contact>
init {
this.mContext = mContext
this.mupdateList = mupdateList
}
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
var contLabel: TextView? = null
var ContactName: TextView? = null
var ContactDetails: LinearLayout? = null
private var ContactProfileImage: ShapeableImageView
init {
contLabel = itemView.findViewById(R.id.contLabel)
ContactProfileImage = itemView.findViewById(R.id.ContactProfileImage)
ContactName = itemView.findViewById(R.id.ContactName)
ContactDetails = itemView.findViewById(R.id.ContactDetails)
}
}
override fun onCreateViewHolder(parent: ViewGroup,viewType: Int): MyViewHolder {
return MyViewHolder(layoutInflater.inflate(R.layout.contacts_row, parent, false))
}
override fun getItemCount(): Int {
return mupdateList.size
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
val contact = mupdateList[position]
with(holder.itemView) {
ContactName.text = contact.name
if(contact.label != null){
contLabel.text = contact.label
if (contact.label == "LEAD"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorPurple))
} else if (contact.label == "Qualified"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorBlueNote))
} else if (contact.label == "Proposal"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorMaroon))
} else if (contact.label == "Client"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorGreen))
} else if (contact.label == "Invoiced"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorYellow))
} else if (contact.label == "Unpaid"){
contLabel.setBackgroundColor(resources.getColor(R.color.ColorRed))
} else if (contact.label == ""){
contLabel.setBackgroundColor(Color.TRANSPARENT)
}
}
Picasso.get().load(contact.photoUri)
.placeholder(R.drawable.ic_baseline_whatshot_24).fit().centerCrop().into(
ContactProfileImage
)
ContactDetails.removeAllViews()
contact.numbers.forEach {
val detail = layoutInflater.inflate(
R.layout.row_contact_data,
ContactDetails,
false
)
detail.imgIcon.setImageResource(R.drawable.ic_local_phone_black_24dp)
detail.ContactData.text = it
ContactDetails.addView(detail)
}
contact.emails.forEach {
val detail = layoutInflater.inflate(
R.layout.row_contact_data,
ContactDetails,
false
)
detail.imgIcon.setImageResource(R.drawable.ic_mail_black_24dp)
detail.ContactData.text = it
ContactDetails.addView(detail)
}
}
holder.itemView.setOnClickListener {
val intent = Intent(mContext, ContactDetailsHome::class.java)
intent.putExtra("contact", contact as Serializable)
intent.putExtra("Edit", true)
mContext.startActivity(intent)
}
holder.itemView.setOnLongClickListener {
val options = arrayOf<CharSequence>(
"Lead",
"Qualified",
"Proposal",
"Client",
"Invoiced",
"Unpaid",
"Clear"
)
var salesTag = ""
val builder: AlertDialog.Builder = AlertDialog.Builder(mContext)
builder.setTitle("Contact is a?")
builder.setItems(options, DialogInterface.OnClickListener { _, which ->
if (which == 0) {
salesTag = "Lead"
updateDB(contact, salesTag)
}
if (which == 1) {
salesTag = "Qualified"
updateDB(contact, salesTag)
}
if (which == 2) {
salesTag = "Proposal"
updateDB(contact, salesTag)
}
if (which == 3) {
salesTag = "Client"
updateDB(contact, salesTag)
}
if (which == 4) {
salesTag = "Invoiced"
updateDB(contact, salesTag)
}
if (which == 5) {
salesTag = "Unpaid"
updateDB(contact, salesTag)
}
if (which == 6) {
salesTag = ""
updateDB(contact, salesTag)
}
})
builder.show()
true
}
}
private fun updateDB(contactL: Contact, salesTag: String) {
val db = AppDatabase.getDatabase(mContext)
val ev = Contact(
contactL.id,
contactL.name,
contactL.lookupKey,
contactL.photoUri,
salesTag,
null
)
db.contactsDao().updateContact(ev)
}
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView)
}
布局文件
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Contacts.ui.ManageContacts">
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/barlayout_contacts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="@style/AppTheme.AppBarOverlay">
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar_contacts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:popupTheme="@style/AppTheme.PopupOverlay">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/actconttitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginStart="8dp"
android:clickable="true"
android:focusable="true"
android:text="CRM"
android:textAllCaps="true"
android:textColor="@color/white"
android:textSize="16sp" />
<TextView
android:id="@+id/contSort"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Sort"
android:textAllCaps="true"
android:textSize="16sp"
android:clickable="true"
android:focusable="true"
android:textColor="@color/white"
android:layout_toStartOf="@+id/contFilter"
android:layout_marginEnd="14dp">
</TextView>
<TextView
android:id="@+id/contFilter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Filter"
android:textAllCaps="true"
android:textSize="16sp"
android:clickable="true"
android:focusable="true"
android:layout_alignParentEnd="true"
android:textColor="@color/white"
android:layout_marginEnd="12dp">
</TextView>
</RelativeLayout>
</androidx.appcompat.widget.Toolbar>
</com.google.android.material.appbar.AppBarLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_below="@+id/barlayout_contacts"
android:background="@color/colorPrimaryDark" />
<EditText
android:id="@+id/user_search_contacts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/barlayout_contacts"
android:layout_marginStart="15dp"
android:layout_marginTop="15dp"
android:layout_marginEnd="15dp"
android:layout_marginBottom="15dp"
android:background="@drawable/textentrybg"
android:hint="Search"
android:padding="9dp"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:textSize="19sp">
</EditText>
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/rvCRM"
android:layout_below="@+id/user_search_contacts"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
/>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/contact_fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_margin="20dp"
android:backgroundTint="#2EBCD9"
android:clickable="true"
android:contentDescription="contact_fab"
android:focusable="true"
android:src="@drawable/ic_baseline_fab_24"
app:backgroundTint="#FFFFFF" />
</RelativeLayout>
LiveData查询不工作，不返回任何值，感谢Soumik指出!通过在没有LiveData的情况下进行标准查询进行测试，它可以工作!