How to display different item layouts in a RecyclerView in Kotlin Android

How to display different item layouts in a RecyclerView in Kotlin Android.

Here's a step-by-step tutorial on how to display different item layouts in a RecyclerView in Kotlin for Android.

Step 1: Set up your project

Create a new Android project in Android Studio and add the necessary dependencies for RecyclerView in your app's build.gradle file:

dependencies {
    // Other dependencies...
    implementation 'androidx.recyclerview:recyclerview:1.2.1'
}

Step 2: Create the layout files

Create the layout files for the different item layouts you want to display in your RecyclerView. For example, let's say you want to display two different layouts: item_layout1.xml and item_layout2.xml. Design these layouts according to your requirements.

Step 3: Create the ViewHolder classes

Create ViewHolder classes for each item layout. These ViewHolder classes will hold references to the views in the corresponding layout files.

class ItemViewHolder1(itemView: View) : RecyclerView.ViewHolder(itemView) {
    // Define references to views in item_layout1.xml
    val textView1: TextView = itemView.findViewById(R.id.text_view1)
    val imageView1: ImageView = itemView.findViewById(R.id.image_view1)
}

class ItemViewHolder2(itemView: View) : RecyclerView.ViewHolder(itemView) {
    // Define references to views in item_layout2.xml
    val textView2: TextView = itemView.findViewById(R.id.text_view2)
    val button1: Button = itemView.findViewById(R.id.button1)
}

Step 4: Create the Adapter class

Create an Adapter class that extends RecyclerView.Adapter and define the necessary methods.

class CustomAdapter(private val itemList: List<Item>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        return when (viewType) {
            ITEM_TYPE_1 -> {
                val view = LayoutInflater.from(parent.context).inflate(R.layout.item_layout1, parent, false)
                ItemViewHolder1(view)
            }
            ITEM_TYPE_2 -> {
                val view = LayoutInflater.from(parent.context).inflate(R.layout.item_layout2, parent, false)
                ItemViewHolder2(view)
            }
            else -> throw IllegalArgumentException("Invalid view type")
        }
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val item = itemList[position]
        when (holder.itemViewType) {
            ITEM_TYPE_1 -> {
                val viewHolder1 = holder as ItemViewHolder1
                // Bind data to views in item_layout1.xml
                viewHolder1.textView1.text = item.text
                viewHolder1.imageView1.setImageResource(item.imageResId)
            }
            ITEM_TYPE_2 -> {
                val viewHolder2 = holder as ItemViewHolder2
                // Bind data to views in item_layout2.xml
                viewHolder2.textView2.text = item.text
                viewHolder2.button1.setOnClickListener {
                    // Perform action for button click
                }
            }
        }
    }

    override fun getItemCount(): Int {
        return itemList.size
    }

    override fun getItemViewType(position: Int): Int {
        // Return the view type for each item in the list
        return itemList[position].type
    }

    companion object {
        private const val ITEM_TYPE_1 = 1
        private const val ITEM_TYPE_2 = 2
    }
}

Step 5: Set up the RecyclerView in your activity or fragment

In your activity or fragment, set up the RecyclerView and attach the adapter to it.

class MainActivity : AppCompatActivity() {

    private lateinit var recyclerView: RecyclerView
    private lateinit var adapter: CustomAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Initialize RecyclerView
        recyclerView = findViewById(R.id.recycler_view)
        recyclerView.layoutManager = LinearLayoutManager(this)

        // Create a list of items with different types
        val itemList = listOf(
            Item("Item 1", R.drawable.image1, CustomAdapter.ITEM_TYPE_1),
            Item("Item 2", R.drawable.image2, CustomAdapter.ITEM_TYPE_1),
            Item("Item 3", R.drawable.image3, CustomAdapter.ITEM_TYPE_2),
            Item("Item 4", R.drawable.image4, CustomAdapter.ITEM_TYPE_2)
        )

        // Create and set the adapter
        adapter = CustomAdapter(itemList)
        recyclerView.adapter = adapter
    }
}

That's it! You have successfully implemented a RecyclerView with different item layouts in Kotlin for Android. Customize the layout files, ViewHolder classes, and adapter as per your specific requirements.