我希望将MVVM模式中的自动完成文本视图与自定义适配器绑定，但不确定如何正确执行。我尝试像使用BindingAdapter进行绑定一样，就像我绑定微调器一样，但是滤镜出现错误。它引发了非法的参数异常。我想我没有正确设置绑定适配器。任何帮助将不胜感激。
<androidx.appcompat.widget.AppCompatAutoCompleteTextView
android:id="@+id/customerNameTextInputLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/customer_name"
android:imeOptions="actionSearch"
android:inputType="textAutoComplete|textAutoCorrect"
android:text="@={addSaleViewModel._customerName}"
android:selectedItemPosition="@={addSaleViewModel.selectedAutoComplete}"
app:partyAutoCompleteAdapter="@{addSaleViewModel.partyList}" />
这是我的适配器代码
class PartyAutoCompleteAdapter(private var items: ArrayList<AddPartyRequest>?) :
BaseAdapter(), PartyListItemViewModel.PartyListItemViewModelListener, Filterable {
private var listFilter: ListFilter? = null
private var dataListAllItems: ArrayList<AddPartyRequest> = ArrayList()
override fun getCount(): Int = items!!.size
override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup): View {
return getView(position, convertView, parent)
}
override fun getItem(position: Int) = items?.get(position)
override fun getItemId(position: Int) = items!!.get(position).partyId.toLong()
override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
lateinit var partyHolder: PartyAutoCompleteHolder
if (convertView == null) {
val binding: RowPartyItemViewBinding = DataBindingUtil.inflate(
LayoutInflater.from(parent.context),
R.layout.row_party_item_view,
parent,
false
)
partyHolder = PartyAutoCompleteHolder(binding)
partyHolder.view.tag = partyHolder
binding.partyItemViewModel = PartyListItemViewModel(position, items?.get(position), this)
binding.executePendingBindings()
} else {
partyHolder = convertView.tag as PartyAutoCompleteHolder
}
return partyHolder.view
}
inner class PartyAutoCompleteHolder(binding: RowPartyItemViewBinding) {
val view = binding.root
}
fun addItems(parties: List<AddPartyRequest>) {
items?.clear()
items?.addAll(parties)
dataListAllItems.clear()
dataListAllItems.addAll(parties)
notifyDataSetChanged()
}
override fun getFilter(): Filter? {
if (listFilter == null) {
listFilter = ListFilter()
}
return listFilter
}
inner class ListFilter : Filter() {
override fun performFiltering(constraint: CharSequence?): Filter.FilterResults? {
var constraint = constraint
val results = Filter.FilterResults()
if (constraint != null && constraint.isNotEmpty()) {
constraint = constraint.toString().toUpperCase()
val filters = ArrayList<AddPartyRequest>()
if (dataListAllItems.size === 0) {
val groupsResponse = AddPartyRequest("", "", "", "", "", "", "", "", "", "", "")
filters.add(groupsResponse)
} else {
for (i in 0 until dataListAllItems.size) {
if (dataListAllItems.get(i).partyName.toUpperCase().contains(constraint)) {
val groupsResponse = AddPartyRequest(
dataListAllItems.get(i).address,
dataListAllItems.get(i).asOfToday,
dataListAllItems.get(i).currentBalance,
dataListAllItems.get(i).email,
dataListAllItems.get(i).gstIn,
dataListAllItems.get(i).partyName,
dataListAllItems.get(i).partyType,
dataListAllItems.get(i).phoneNumber,
dataListAllItems.get(i).state,
dataListAllItems.get(i).userCompanyId,
dataListAllItems.get(i).partyId
)
filters.add(groupsResponse)
}
}
}
results.count = filters.size
results.values = filters
} else {
results.count = dataListAllItems.size
results.values = dataListAllItems
}
return results
}
override fun publishResults(constraint: CharSequence, results: Filter.FilterResults?) {
items = results?.values as ArrayList<AddPartyRequest>
notifyDataSetChanged()
}
}
override fun onItemClick(view: View, position: Int) {
}
}
输入任何字符后我在自定义适配器中遇到的错误
java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull, parameter constraint
at in.diittech.diitvyapar.ui.adapter.PartyAutoCompleteAdapter$ListFilter.publishResults(Unknown Source:24)
at android.widget.Filter$ResultsHandler.handleMessage(Filter.java:282)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
答案 0 :(得分：1)
这就是我的做法。可能会晚一点，但也许其他人可能会使用它。
AutoCompleteTextView：
class BindingAutoCompleteTextView(context: Context, attributeSet: AttributeSet) : AutoCompleteTextView(context, attributeSet) {
var selectedItem: Any? = null
}//Cls
//=====================================================================================================//
//=====================================================================================================//
@InverseBindingAdapter(attribute = "app:selectedItem")
fun getSelectedItem(bindingActv: BindingAutoCompleteTextView): Any? {
return bindingActv.selectedItem
}//getSelectedItem
//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -//
@BindingAdapter("selectedItemAttrChanged")
fun selectedItemAttrChanged(actv: BindingAutoCompleteTextView, listener: InverseBindingListener) {
actv.setOnItemClickListener { parent, _, position, _ ->
actv.selectedItem = parent.adapter.getItem(position)
listener.onChange()
}
}//selectedItemAttrChanged
//- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -//
@BindingAdapter("app:adapter")
fun setAdapter(actv: AutoCompleteTextView, adapter: FilterableBaseAdapter?) {
adapter?.let {
actv.setAdapter(adapter)
}
}//setAdapter
//=====================================================================================================//
//=====================================================================================================//
/**
* Class to be used as type parameter in functions
*/
abstract class FilterableBaseAdapter : BaseAdapter(), Filterable
//=====================================================================================================//
//=====================================================================================================//
布局：
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:bind="http://schemas.android.com/tools">
<data>
<variable
name="viewModel"
type="ie.conecto.ui.salesOrder.SalesOrderViewModel" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ie.conecto.infastructure.ui.BindingAutoCompleteTextView
android:id="@+id/acCustomer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:completionThreshold="2"
android:hint="@string/select_customer"
android:textAlignment="center"
android:textSize="20sp"
app:adapter="@{viewModel.adapter}"
app:selectedItem="@={viewModel.orderItem}"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:layout_width="match_parent"
android:layout_height="19dp"
android:background="@color/colorPrimaryLight"
android:text='@{viewModel.orderItem.description}'
android:textAlignment="center"
app:layout_constraintTop_toBottomOf="@id/acCustomer" />
<include
layout="@layout/progress_overlay"
bind:show="@{viewModel.showProgress}" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
ViewModel：
private const val TAG = "SalesOrderViewModel"
class SalesOrderViewModel(
private val _productRepo: IProductRepo,
private val _customerRepo: ICustomerRepo
) : ViewModel() {
var orderItem = MutableLiveData<OrderItem?>()
val products by lazyDeferred {
_productRepo.getProducts()
}
val customers by lazyDeferred {
_customerRepo.getCustomers()
}
val showProgress: LiveData<Boolean>
get() = _showProgress
private var _showProgress = MutableLiveData<Boolean>()
val adapter: LiveData<ProductAutoCompleteTextViewAdapter>
get() = _adapter
private var _adapter = MutableLiveData<ProductAutoCompleteTextViewAdapter>()
var backgroundTaskResultListener: BackgroundTaskResultListener? = null
//--------------------------------------------------------------------------------/
init {
Coroutines.main {
Log.d(TAG, "init")
_showProgress.postValue(true)
products
.await()
.observeForever { products ->
context.let {
_adapter.postValue(ProductAutoCompleteTextViewAdapter(products))
_adapter.value?.notifyDataSetChanged()
if (products.isNotEmpty())
_showProgress.postValue(false)
}
}//observe
}//main
}//init
//--------------------------------------------------------------------------------//
}//Cls