This is what I created
And what I want is like this below
Actually in here, I want my cards should look like cards in a wallet (as shown in the 2nd image above) which I can scroll like the native stack card view as shown in first image, problem I am facing is I am not able to align cards vertically straight, cards get cut if I try to do so.
I want to achieve this behaviour using Android Native stackview widget only.
My code is as below:
ActivityMain.kt
class MainActivity : AppCompatActivity() {
lateinit var cardAdapter: CardAdapter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val stackView = findViewById<StackView>(R.id.stack_view)
cardAdapter= CardAdapter(numberWord(),numberImage(),R.layout.item_card,this)
stackView.adapter=cardAdapter
}
// the method numberWord() is used to
// add the text below corresponding images.
private fun numberWord(): List<String> {
val word: MutableList<String> = ArrayList()
word.add("One")
word.add("Two")
word.add("Three")
word.add("Four")
word.add("Five")
return word
}
// the method numberWord() is used to call
// the images that are added to the stack.
private fun numberImage(): List<Int>{
val image: MutableList<Int> = ArrayList()
image.add(R.drawable.ic_filter)
image.add(R.drawable.ic_filter)
image.add(R.drawable.ic_filter)
image.add(R.drawable.ic_filter)
image.add(R.drawable.ic_filter)
return image
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<!--We have used RelativeLayout for layout-->
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".MainActivity">
<!--Add StackView-->
<StackView
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintTop_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:id="#+id/stack_view"
android:layoutDirection="ltr"
android:layout_width="400dp"
android:layout_height="300dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
CardAdapter.kt
class CardAdapter
(
var numberWord: List<String>,
var numberImage: List<Int>,
var itemLayout: Int,
var c: Context
) : ArrayAdapter<Any?>(
c, itemLayout, numberWord
) {
// getCount() is called to return
// the total number of words to be used
override fun getCount(): Int {
return numberWord.size
}
// getView() is called to get position,
// parent and view of the images.
override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
var convertView = convertView
if (convertView == null) {
convertView = LayoutInflater.from(parent.context).inflate(itemLayout, parent, false)
}
val word = numberWord[position]
val image = numberImage[position]
val textView = convertView!!.findViewById<TextView>(R.id.text_view)
val imageView = convertView.findViewById<ImageView>(R.id.image_view)
textView.text = word
imageView.setImageResource(image)
return convertView
}
}
item_card.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="300dp"
android:layout_height="180dp"
android:background="#drawable/border_bg"
android:gravity="center"
android:orientation="vertical">
<ImageView
android:id="#+id/image_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_filter" />
<TextView
android:id="#+id/text_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="40sp"
android:textStyle="bold" />
</LinearLayout>
you guys can refer android native stackview: https://developer.android.com/reference/android/widget/StackView
I tried many different solution, I guess we can achieve that with third party library but that's not what I want. I want to create solution with using native android stackview.
Any help will be great.
Related
I am trying to fetch the data from Google Spreadsheet and display it in a recyclerView in Kotlin. I could do that without any error but the issue I am facing is when I scroll up or down the data in the recyclerView get disappeared. When I scroll up and then scroll down I can see that all the data that went up is missing and the same with scrolling down. But if I scroll up for more I can see one line of data after every few scrolls.
Another issue I have is with the date that is being displayed. My data in the Google Spreadsheet starts from 01-Jan-2023 (this is how it's shown in the spreadsheet, and without time in it), when it's shown in the recyclerView, all dates are one day earlier. I mean, it shows 31-Dec-2022 for 01-Jan-2023, 01-Jan-2023 for 02-Jan-2023 and so on.
Can somebody help correct my mistakes and improve my code? I have been after this for a couple of days and I couldn't fix the issue.
My code is,
SalesData.kt
class SalesData : AppCompatActivity() {
private lateinit var binding: ActivitySalesDataBinding
#SuppressLint("NotifyDataSetChanged")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivitySalesDataBinding.inflate(layoutInflater)
setContentView(binding.root)
val salesList = arrayListOf<SalesDataModel>()
val queue = Volley.newRequestQueue(this)
val url = "https://script.google.com/macros/s/AKfsdaffdbghjhfWVM2FeIH3gZY5kAnb6JVeWpg2XeBOZyU6sghhfkuytytg/exec"
val jsonObjectRequest = object: JsonObjectRequest(
Request.Method.GET,url,null,
Response.Listener {
val data = it.getJSONArray("items")
for(i in 0 until data.length()){
val salesJasonObject = data.getJSONObject(i)
val dt = salesJasonObject.getString("Date")
val dateFmt = SimpleDateFormat("yyyy-MM-dd", Locale.US).parse(dt)
val formattedDatesString = dateFmt?.let { it1 -> SimpleDateFormat("dd-MMM-yyyy", Locale.US).format(it1) }
val salesObject = formattedDatesString?.let { it1 ->
SalesDataModel(
// salesJasonObject.getString("Date"),
it1,
salesJasonObject.getString("Branch"),
salesJasonObject.getDouble("NetSale"),
salesJasonObject.getDouble("Profit"),
)
}
if (salesObject != null) {
salesList.add(salesObject)
}
val adapter = SalesDataRecyclerAdapter(this#SalesData,salesList)
binding.rvSalesData.adapter = adapter
binding.rvSalesData.layoutManager = LinearLayoutManager(this#SalesData)
binding.rvSalesData.setHasFixedSize(true)
adapter.notifyDataSetChanged()
}
Toast.makeText(this#SalesData, "Data loaded successfully", Toast.LENGTH_LONG).show()
},Response.ErrorListener {
Toast.makeText(this#SalesData, it.toString(), Toast.LENGTH_LONG).show()
}
){
override fun getHeaders(): MutableMap<String, String> {
return super.getHeaders()
}
}
Toast.makeText(this#SalesData, "Hi", Toast.LENGTH_LONG).show()
queue.add(jsonObjectRequest)
}
}
SalesDataRecyclerAdapter.kt
class SalesDataRecyclerAdapter(
val context: Context,
private val saleDataList:ArrayList<SalesDataModel>
):RecyclerView.Adapter<RecyclerView.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
return MyViewHolder(
SalesDataLayoutBinding.inflate(
LayoutInflater.from(parent.context),
parent, false
)
)
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
val model = saleDataList[position]
if (holder is MyViewHolder){
holder.binding.tvSales.text = model.salesAmount.toString()
holder.binding.tvBranch.text = model.branch
holder.binding.tvDate.text = model.date
holder.binding.tvProfit.text = model.profit.toString()
}
}
override fun getItemCount(): Int {
return saleDataList.size
}
class MyViewHolder(val binding: SalesDataLayoutBinding) : RecyclerView.ViewHolder(binding.root)
}
activity_sales_data.xml
<androidx.constraintlayout.widget.ConstraintLayout 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"
android:background="#color/white"
tools:context=".SalesData">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<!--
<androidx.core.widget.ContentLoadingProgressBar
android:id="#+id/progressbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>-->
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/new_green"
android:padding="10dp"
android:text="SALES DATA"
android:textColor="#color/white"
android:textSize="24sp"
android:layout_gravity="bottom|end"/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvSalesData"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
sales_data_layout.xml
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="#+id/tvDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Date"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvBranch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Branch"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvSales"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Sales"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvProfit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Profit"
android:layout_weight="1"/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
Since your root view in sales_data_layout.xml has the size:
android:layout_width="match_parent"
android:layout_height="match_parent"
Each item will take up the whole parent area, which in your case will end up with each individual item taking up the whole screen, and thus needing multiple scrolls to see the next item. You probably want to change the height to wrap_content for the root view, to see more items on the screen at once.
Add a comparator that tells the recylcer view exactly when to redraw.
class WordsComparator : DiffUtil.ItemCallback<Word>() {
override fun areItemsTheSame(oldItem: Word, newItem: Word): Boolean {
//=== here doesn't work for complex objects
// simple high-speed code goes here it is called over and over
// my app the same item has the same id easy compare
return (oldItem._id == newItem._id)
}
override fun areContentsTheSame(oldItem: Word, newItem: Word): Boolean { // you developer have to compare the contents of complex objects
// you need high speed code here for best results
// if possible don't call any functions that could do other
// unecessary things.
// compare the contents of the complex items.
return (oldItem._id == newItem._id
&& oldItem.checked == newItem.checked
&& oldItem.word == newItem.word
&& oldItem.color == newItem.color
&& oldItem.recolor == newItem.recolor
&& oldItem.rechecked == newItem.rechecked)
}
}
I'm a Kotlin newbie learning how to create simple recyclerview apps. My code is supposed to list the integers 1..10 in vertically stacked cells. However, it only lists the first item. I've consulted several tutorials and reviewed my code several times(after long breaks), but I can't see anything wrong in my code.
I got the bright idea early today to print Log statements. Examining them, I note that my onBindViewHolder function is only called once. What blunder am I making?
Here is my log output:
D/QuoteAdapter: value is: 1
D/QuoteAdapter: index is: 0
D/QuoteAdapter: Size is: 10
my activity:
class MainActivity : AppCompatActivity() {
lateinit var mRecyclerView: RecyclerView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
mRecyclerView = findViewById(R.id.recyclerView)
mRecyclerView.layoutManager = LinearLayoutManager(this)
mRecyclerView.adapter = QuoteAdapter()
//mRecyclerView.setHasFixedSize(true)
}
}
my adapter:
class QuoteAdapter : RecyclerView.Adapter<QuoteViewHolder>() {
private val listOfInts = intArrayOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
private val TAG = "QuoteAdapter"
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): QuoteViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.recyclerview_item_row, parent, false)
return QuoteViewHolder(view)
}
override fun getItemCount(): Int {
Log.d(TAG, "Size is: ${listOfInts.size.toString()}")
return listOfInts.size
}
override fun onBindViewHolder(holder: QuoteViewHolder, position: Int) {
val item = listOfInts[position]
Log.d(TAG, "value is: ${item.toString()}")
Log.d(TAG, "index is: ${position.toString()}")
holder.listTitle.text = item.toString()
}
}
my viewholder:
class QuoteViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val listTitle = itemView.findViewById(R.id.itemString) as TextView
}
my layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/itemString"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
my main layout is shown below:
<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
In your "my layout" try this:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/itemString"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>
Notice layout_height of LinearLayout has changed to wrap_content
Also doubt you need the android:orientation="vertical" on your ViewHolders item xml unless you will add more than just 1 TextView in the future.
Like Zain says, you can just use a TextView on its own in a layout file, which will also fix the problem (so long as its height is wrap_content!)
There are actually a few included with Android - type android.R.layout. and you'll see a few things, like simple_list_item_1 which is just a styled TextView (you can ctrl+click the reference or whatever to look at the file). Can be nice if you just want to make a quick thing!
The ID of the TextView in android.R.layout.simple_list_item_1 is #android:id/text1 - note the android prefix, because its part of the android resources, not your app's. Which means you have to reference the ID in the same way as the layout, with android at the front: android.R.id.text1
You can get rid of the LinearLayout in the list item layout, and only keep the TextView.
So, replace your list item layout with:
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/itemString"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
I am brand new in Android/kotlin development. I created my very first app with a recyclerView to display the folders and files of the phone. I put the recyclerView into a segment, created my data structure and adapter. Assembled together. It works - or seems to work. But the problem is that when I try to scroll the list, the initial state remains "ther" and the list content starts to scroll. Like it was two different layers. I have no clue where to find the problem. Never heard about such a bug like this. Please give me advice, some keywords where to dig and find the solution. Thanks!
class BrowseFileFragment : Fragment() {
private lateinit var attachedCtx : Context
override fun onAttach(context: Context) {
super.onAttach(context)
this.attachedCtx = context
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,savedInstanceState: Bundle?): View?
{
var view : View = inflater.inflate(R.layout.fragment_browse_file, container, false)
val modelFactory = FileBrowseModelFactory()
val data = modelFactory.create()
bindModelToView(data, view)
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
}
private fun bindModelToView(data: BrowseSettings, view: View)
{
var adapter = MyFileAdapter(data.FoldersAndFiles, this.attachedCtx)
var recyclerView = view.findViewById<RecyclerView>(R.id.fileItemView)
var linearLayoutManager = LinearLayoutManager(this.attachedCtx)
recyclerView.layoutManager = linearLayoutManager
recyclerView.adapter = adapter
var folderLabel = view.findViewById<TextView>(R.id.folderName)
folderLabel.text = data.CurrentFolder
}
}
The segment layout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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=".BrowseFileFragment">
<TextView
android:id="#+id/folderName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:text="#string/hello_first_fragment"
android:textAlignment="viewStart"
android:textAppearance="#style/TextAppearance.AppCompat.Display1"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/fileItemView"
android:layout_width="match_parent"
app:layout_constrainedHeight="true"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="#+id/folderName"
app:layout_constraintStart_toStartOf="#+id/folderName"
app:layout_constraintTop_toBottomOf="#+id/folderName" />
</androidx.constraintlayout.widget.ConstraintLayout>
The list line layout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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="60dp">
<TextView
android:background="#color/cardview_shadow_start_color"
android:id="#+id/itemName"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toTopOf="parent"
android:padding="5dp"
android:textSize="30dp"
android:textStyle="bold" />
</androidx.constraintlayout.widget.ConstraintLayout>
And finally my adapter:
class MyFileAdapter(private val items: List<FileItem>, private val context: Context)
: RecyclerView.Adapter<MyFileAdapter.MyViewHolder>()
{
class MyViewHolder (itemView: View) :RecyclerView.ViewHolder(itemView), View.OnClickListener {
init {
itemView.setOnClickListener(this)
}
fun bindItem(f: FileItem) {
var name: TextView = itemView.findViewById(R.id.itemName) as TextView
name.text = f.Name
}
}
override fun getItemCount() = items.size
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val view = LayoutInflater
.from(context)
.inflate(R.layout.recyclerview_filteitem_row, parent, false)
return MyViewHolder(view)
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
var item = items\[position\]
holder!!.bindItem( item )
}
}
It found out that as the whole list view is saved as a segment, this segment loads "automatically" and was loaded programatically also, and the two "loads" causes this thing. :( Thanks for your time guys.
Why do I get a NullPointerException in my ViewHolder's bindItems() method?
I've highlighted the line where I get the NullPointerException. The blogpost_author ID exists, as you can see in the XML, so what's the problem here? How is findViewById<TextView>(R.id.blogpost_author) returning null?
Adapter and ViewHolder code:
class BlogPostAdapter(val blogList: ArrayList<BlogPost>) : RecyclerView.Adapter<BlogPostAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) : BlogPostAdapter.ViewHolder {
val v = LayoutInflater.from(parent.context).inflate(R.layout.blog_post_list, parent, false)
return ViewHolder(v)
}
override fun getItemCount(): Int {
return blogList.size
}
override fun onBindViewHolder(holder: BlogPostAdapter.ViewHolder, position: Int) {
holder.bindItems(blogList[position])
}
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bindItems(blogPost: BlogPost) {
val blogPostAuthor = itemView.findViewById<TextView>(R.id.blogpost_author) // THIS LINE - NULL POINTER EXCEPTION
val blogPostTitle = itemView.findViewById<TextView>(R.id.blogpost_title)
blogPostAuthor.text = blogPost.author
blogPostTitle.text = blogPost.title
}
}
}
Activity code:
class BlogPostListActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.blog_post_list)
// Get the RecyclerView from XML itself
val recyclerView = findViewById<RecyclerView>(R.id.recyclerview)
// Add a layout manager - What does a layout manager do?
recyclerView.layoutManager = LinearLayoutManager(this, LinearLayout.VERTICAL, false)
// Create an array list to store blogposts using the the data class blogPost
val blogPosts = ArrayList<BlogPost>()
// Add some dummy data to the list
blogPosts.add(BlogPost(123, "First Blog Post", "John"))
blogPosts.add(BlogPost(456, "Second Blog Post", "Bob"))
blogPosts.add(BlogPost(789, "Third Blog Post", "Mary"))
// Create an adapter
val adapter = BlogPostAdapter(blogPosts)
// Add the adapter to the recyclerview
recyclerView.adapter = adapter
}
}
Kotlin data class:
data class BlogPost(val id: Int, val title: String, val author: String)
XML for RecyclerView:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="com.topzap.android.kotlinlistapptest.BlogPostListActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:layout_editor_absoluteX="8dp"
tools:layout_editor_absoluteY="8dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
XML for CardView layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/blogpost_author"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:text="AuthorPlaceHolder"
android:textAppearance="#style/Base.TextAppearance.AppCompat.Large"
/>
<TextView
android:id="#+id/blogpost_title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="5dp"
android:text="TitlePlaceHolder"
android:textAppearance="#style/Base.TextAppearance.AppCompat.Medium"
/>
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
You may be inflating the wrong layout within your RecyclerView.
This line within your onCreateViewHolder method:
val v = LayoutInflater.from(parent.context).inflate(R.layout.blog_post_list, parent, false)
You are inflating the blog_post_list.xml, which I'm assuming is the wrong layout file due to the fact you're also inflating that layout within your BlogPostListActivity here:
setContentView(R.layout.blog_post_list)
So when this line is called:
val blogPostAuthor = itemView.findViewById<TextView>(R.id.blogpost_author)
It is looking for the id 'blogpost_author' within R.layout.blog_post_list and as you can see there is no blogpost_author TextView within that layout so it returns null.
To sort it out, it should be straight forward and just change the layout resource that you're assigning to each ViewHolder within your onCreateViewHolder method with the correct layout for your CardView layout.
Which means the line should read something like:
val v = LayoutInflater.from(parent.context).inflate(R.layout.your_card_layout, parent, false)
i want set many buttons (i mean clickable views) in item of recyclerView like every item has download,play,stop,delete how can i do that? if i setOnlickListener like holder.download_image.setOnClickListenr(){} its works for all item i want every item has difrent link for download
class RecyclerAdapter(private val soundList: List<SoundItem>,private val mListener: AdapterView.OnItemClickListener?) :
RecyclerView.Adapter<RecyclerAdapter.RecyclerViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerViewHolder {
val itemView =
LayoutInflater.from(parent.context).inflate(R.layout.recycler_view, parent, false)
return RecyclerViewHolder(itemView)
}
override fun onBindViewHolder(holder: RecyclerViewHolder, position: Int) {
val currnetItem = soundList[position]
holder.soundNmae.text = currnetItem.soundName
holder.play_image.setImageResource(currnetItem.playImage)
holder.stop_image.setImageResource(currnetItem.stopImage)
holder.download_image.setImageResource(currnetItem.donloadImage)
holder.delete_image.setImageResource(currnetItem.deleteImage)
}
override fun getItemCount() = soundList.size
class RecyclerViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val soundNmae = itemView.soundName
val play_image = itemView.play_image
val stop_image = itemView.stop_image
val download_image = itemView.download_image
val delete_image = itemView.delete_image
}
}
this is acivity for recyclerView im new in kotlin sorry if my question is maybe simple or i couldent say if what is my mean
class RelaxSoundActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_relax_sound)
val exampleList=generatorSoundList(500)
recyceler_view.adapter=RecyclerAdapter(exampleList)
recyceler_view.layoutManager=LinearLayoutManager(this)
recyceler_view.setHasFixedSize(true)
}
fun generatorSoundList(size:Int ):List<SoundItem>{
val list=ArrayList<SoundItem>()
for(i in 0 until size){
val drawable=when(i % 5){
0->R.drawable.ic_play_arrow_black_24dp
1->R.drawable.ic_play_arrow_black_24dp
2->R.drawable.ic_play_arrow_black_24dp
3->R.drawable.ic_play_arrow_black_24dp
else->R.drawable.ic_play_arrow_black_24dp
}
val drawable2=when(i % 5){
0->R.drawable.ic_stop_black_24dp
1->R.drawable.ic_stop_black_24dp
2->R.drawable.ic_stop_black_24dp
3->R.drawable.ic_stop_black_24dp
else->R.drawable.ic_stop_black_24dp
}
val drawable3=when(i % 5){
0->R.drawable.ic_file_download_black_24dp
1->R.drawable.ic_file_download_black_24dp
2->R.drawable.ic_file_download_black_24dp
3->R.drawable.ic_file_download_black_24dp
else->R.drawable.ic_file_download_black_24dp
}
val drawable4=when(i % 5){
0->R.drawable.ic_delete_black_24dp
1->R.drawable.ic_delete_black_24dp
2->R.drawable.ic_delete_black_24dp
3->R.drawable.ic_delete_black_24dp
else->R.drawable.ic_delete_black_24dp
}
val item=SoundItem("item $i" ,drawable,drawable2,drawable3,drawable4)
list+=item
}
return list
}
}
and recycler_view.xml file is here
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent" android:layout_height="wrap_content"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:padding="8dp"
>
<TextView
android:id="#+id/soundName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
android:text="TextView"
android:textSize="20dp"/>
<ImageView
android:id="#+id/play_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
app:srcCompat="#drawable/ic_play_arrow_black_24dp" />
<ImageView
android:id="#+id/stop_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
app:srcCompat="#drawable/ic_stop_black_24dp" />
<ImageView
android:id="#+id/download_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
app:srcCompat="#drawable/ic_file_download_black_24dp" />
<ImageView
android:id="#+id/delete_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"
app:srcCompat="#drawable/ic_delete_black_24dp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
you can do it in multiple ways. You can add click listeners on your views and directly perform the operation in your adapter or you can transfer function in your recycler view holder class.
So for short cut I can just give you the way that you can understand the process.
In you adapter onBindViewHolder you can add
holder.download_image.setOnCLickListener{
val downloadLink = currnetItem.getDownloadLink()
// Download task start by this download link
}
So this one click listener on download image will be effected on each item and perform separately.
IMO you have to attach an clicklistener to each button, and then you could either make a callback to the adapter/activity and handle it from there on.
If you yous the View.OnClickListener, then you always have the clicked view. From there on, it is just a matter of writing a switch statement, where you can determine via the id of the clicked view, which action was selected.
If you need extra data, you could just add a tag to the view, and pass it via the clickListener.