如何在 RecyclerView 列表项中包含多个 TextView
How can I have multiple TextViews inside a RecyclerView list item
我知道 RecyclerView 列表很灵活，每个项目可以有多个视图。我找不到任何好的示例代码来帮助我实现它。
我正在尝试实现一个简单的 RecyclerView 列表，其中每个列表项都是我创建的自定义 .xml 布局。 RecyclerView.Adapter 必须做什么才能通过自定义布局文件中的 ID 访问每个不同的视图并更新每个值？
我基本上从 Android Docs.
复制了以下代码
//ScannedDevicesListAdapter.kt
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
class ScannedDevicesListAdapter(private val myDataset: Array<String>) :
RecyclerView.Adapter<ScannedDevicesListAdapter.ScannedDevicesListViewHolder>() {
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder.
// Each data item is just a string in this case that is shown in a TextView.
class ScannedDevicesListViewHolder(val textView: TextView) : RecyclerView.ViewHolder(textView)
// Create new views (invoked by the layout manager)
override fun onCreateViewHolder(parent: ViewGroup,
viewType: Int): ScannedDevicesListAdapter.ScannedDevicesListViewHolder {
// create a new view
val textView = LayoutInflater.from(parent.context)
.inflate(R.layout.scanned_devices_list_item, parent, false) as TextView
// set the view's size, margins, paddings and layout parameters
return ScannedDevicesListViewHolder(textView)
}
// Replace the contents of a view (invoked by the layout manager)
override fun onBindViewHolder(holder: ScannedDevicesListViewHolder, position: Int) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.textView.text = myDataset[position]
}
// Return the size of your dataset (invoked by the layout manager)
override fun getItemCount() = myDataset.size
}
这是我的自定义视图的 .xml 文件：
Screenshot of the custom list item
//scanned_devices_list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="30dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/TextView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 1" />
<TextView
android:id="@+id/TextView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 2" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal">
<TextView
android:id="@+id/TextView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 3" />
</LinearLayout>
</LinearLayout>
您应该更改 ViewHolder 实现，因为它应该将您的父级 View（来自 xml 文件）作为参数而不是 TextView。 TextViews 是子项，可以在您的 ViewHolder:
中定义为成员变量
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
class ScannedDevicesListAdapter(private val myDataset: Array<String>) :
RecyclerView.Adapter<ScannedDevicesListAdapter.ScannedDevicesListViewHolder>() {
class ScannedDevicesListViewHolder(val view: View) : RecyclerView.ViewHolder(view) {
val tv1 = view.TextView1
val tv2 = view.TextView2
val tv3 = view.TextView3
}
// Create new views (invoked by the layout manager)
override fun onCreateViewHolder(parent: ViewGroup,
viewType: Int):
ScannedDevicesListAdapter.ScannedDevicesListViewHolder {
// create a new view
val linearLayout = LayoutInflater.from(parent.context)
.inflate(R.layout.scanned_devices_list_item, parent, false) as View
// set the view's size, margins, paddings and layout parameters
return ScannedDevicesListViewHolder(linearLayout)
}
override fun onBindViewHolder(holder: ScannedDevicesListViewHolder, position: Int) {
holder.tv1.text = myDataset[position]
// set your other views here
}
// Return the size of your dataset (invoked by the layout manager)
override fun getItemCount() = myDataset.size
}
你可以试试这个....
class sel_cat_adapter(ctx: Context, list: MutableList<Any>) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private var ctx: Context = ctx
private var list: MutableList<Any> = list
private var ITEM = 0
private var Ads = 1
var ITEM_PER_Ad = 5
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
when (viewType) {
ITEM -> {
var inflater =
LayoutInflater.from(ctx).inflate(R.layout.customlayoutfor_sel_cat, null, false)
return viewholderclass(inflater)
}
Ads -> {
var inflater = LayoutInflater.from(ctx).inflate(R.layout.ads_banner, null, false)
return AdsViewHolder(inflater)
}
else -> {
var inflater = LayoutInflater.from(ctx).inflate(R.layout.ads_banner, null, false)
return AdsViewHolder(inflater)
}
}
}
override fun getItemCount(): Int {
return list.size
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
var viewtype = getItemViewType(position)
when (viewtype) {
ITEM -> {
var myholder = holder as viewholderclass
}
Ads -> {
var myholder = holder as AdsViewHolder
}
else -> {
}
}
holder.itemView.setOnClickListener {
if (viewtype == ITEM) {
Toast.makeText(ctx, "Item", Toast.LENGTH_LONG).show()
} else {
Toast.makeText(ctx, "Ads", Toast.LENGTH_LONG).show()
}
}
}
override fun getItemViewType(position: Int): Int {
return if (position % ITEM_PER_Ad == 0) {
if (list[position] is AdView) {
Ads
} else {
ITEM
}
} else {
ITEM
}
}
class AdsViewHolder(itemview: View) : RecyclerView.ViewHolder(itemview){
}
class viewholderclass(itemview: View) : RecyclerView.ViewHolder(itemview) {
}
}
我知道 RecyclerView 列表很灵活，每个项目可以有多个视图。我找不到任何好的示例代码来帮助我实现它。
我正在尝试实现一个简单的 RecyclerView 列表，其中每个列表项都是我创建的自定义 .xml 布局。 RecyclerView.Adapter 必须做什么才能通过自定义布局文件中的 ID 访问每个不同的视图并更新每个值？
我基本上从 Android Docs.
复制了以下代码//ScannedDevicesListAdapter.kt
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
class ScannedDevicesListAdapter(private val myDataset: Array<String>) :
RecyclerView.Adapter<ScannedDevicesListAdapter.ScannedDevicesListViewHolder>() {
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder.
// Each data item is just a string in this case that is shown in a TextView.
class ScannedDevicesListViewHolder(val textView: TextView) : RecyclerView.ViewHolder(textView)
// Create new views (invoked by the layout manager)
override fun onCreateViewHolder(parent: ViewGroup,
viewType: Int): ScannedDevicesListAdapter.ScannedDevicesListViewHolder {
// create a new view
val textView = LayoutInflater.from(parent.context)
.inflate(R.layout.scanned_devices_list_item, parent, false) as TextView
// set the view's size, margins, paddings and layout parameters
return ScannedDevicesListViewHolder(textView)
}
// Replace the contents of a view (invoked by the layout manager)
override fun onBindViewHolder(holder: ScannedDevicesListViewHolder, position: Int) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
holder.textView.text = myDataset[position]
}
// Return the size of your dataset (invoked by the layout manager)
override fun getItemCount() = myDataset.size
}
这是我的自定义视图的 .xml 文件：
Screenshot of the custom list item
//scanned_devices_list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="30dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/TextView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 1" />
<TextView
android:id="@+id/TextView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 2" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="horizontal">
<TextView
android:id="@+id/TextView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
tools:text="Field 3" />
</LinearLayout>
</LinearLayout>
您应该更改 ViewHolder 实现，因为它应该将您的父级 View（来自 xml 文件）作为参数而不是 TextView。 TextViews 是子项，可以在您的 ViewHolder:
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
class ScannedDevicesListAdapter(private val myDataset: Array<String>) :
RecyclerView.Adapter<ScannedDevicesListAdapter.ScannedDevicesListViewHolder>() {
class ScannedDevicesListViewHolder(val view: View) : RecyclerView.ViewHolder(view) {
val tv1 = view.TextView1
val tv2 = view.TextView2
val tv3 = view.TextView3
}
// Create new views (invoked by the layout manager)
override fun onCreateViewHolder(parent: ViewGroup,
viewType: Int):
ScannedDevicesListAdapter.ScannedDevicesListViewHolder {
// create a new view
val linearLayout = LayoutInflater.from(parent.context)
.inflate(R.layout.scanned_devices_list_item, parent, false) as View
// set the view's size, margins, paddings and layout parameters
return ScannedDevicesListViewHolder(linearLayout)
}
override fun onBindViewHolder(holder: ScannedDevicesListViewHolder, position: Int) {
holder.tv1.text = myDataset[position]
// set your other views here
}
// Return the size of your dataset (invoked by the layout manager)
override fun getItemCount() = myDataset.size
}
你可以试试这个....
class sel_cat_adapter(ctx: Context, list: MutableList<Any>) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private var ctx: Context = ctx
private var list: MutableList<Any> = list
private var ITEM = 0
private var Ads = 1
var ITEM_PER_Ad = 5
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
when (viewType) {
ITEM -> {
var inflater =
LayoutInflater.from(ctx).inflate(R.layout.customlayoutfor_sel_cat, null, false)
return viewholderclass(inflater)
}
Ads -> {
var inflater = LayoutInflater.from(ctx).inflate(R.layout.ads_banner, null, false)
return AdsViewHolder(inflater)
}
else -> {
var inflater = LayoutInflater.from(ctx).inflate(R.layout.ads_banner, null, false)
return AdsViewHolder(inflater)
}
}
}
override fun getItemCount(): Int {
return list.size
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
var viewtype = getItemViewType(position)
when (viewtype) {
ITEM -> {
var myholder = holder as viewholderclass
}
Ads -> {
var myholder = holder as AdsViewHolder
}
else -> {
}
}
holder.itemView.setOnClickListener {
if (viewtype == ITEM) {
Toast.makeText(ctx, "Item", Toast.LENGTH_LONG).show()
} else {
Toast.makeText(ctx, "Ads", Toast.LENGTH_LONG).show()
}
}
}
override fun getItemViewType(position: Int): Int {
return if (position % ITEM_PER_Ad == 0) {
if (list[position] is AdView) {
Ads
} else {
ITEM
}
} else {
ITEM
}
}
class AdsViewHolder(itemview: View) : RecyclerView.ViewHolder(itemview){
}
class viewholderclass(itemview: View) : RecyclerView.ViewHolder(itemview) {
}
}