Hello Guys, in this Post we are going to learn how to use Recyclerview in Kotlin with AndroidX dependencies. For this Example we need to create below classes. Before that we need to add dependencies in app level build.gradle file 




dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'androidx.appcompat:appcompat:1.0.0-beta01'
    implementation 'androidx.core:core-ktx:1.2.0-rc01'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.0-alpha4'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha4'
    implementation 'androidx.recyclerview:recyclerview:1.1.0'
    implementation 'androidx.cardview:cardview:1.0.0'
}


MainActivity.kt

class MainActivity : AppCompatActivity() {

    var index_array:Array?=null;
    var recyclerview:RecyclerView?=null;
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        recyclerview=findViewById(R.id.recyclerview);
        recyclerview?.layoutManager=LinearLayoutManager(this,RecyclerView.VERTICAL,false);

        index_array=resources.getStringArray(R.array.index);
        recyclerview?.adapter=RecyclerviewAdapter(index_array!!);
    }
}


RecyclerviewAdapter.kt 

    class RecyclerviewAdapter(_array:Array): RecyclerView.Adapter() {
    var index_array=_array;
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.layout_list_item,parent,false));
    }

    override fun getItemCount(): Int {

        return index_array.size;
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
       holder.text_item.setText(index_array[position])
    }

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

        var text_item = itemView.findViewById(R.id.text_item);
    }
}


activity_main.xml 

    
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="https://schemas.android.com/apk/res/android"
        xmlns:tools="https://schemas.android.com/tools"
        xmlns:app="https://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity" >

    <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerview"
            android:layout_width="match_parent"

            android:layout_height="match_parent"/>


</androidx.constraintlayout.widget.ConstraintLayout>


layout_list_item.xml 

    <androidx.cardview.widget.CardView
        xmlns:android="https://schemas.android.com/apk/res/android"
        xmlns:app="https://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="5dp"
        android:padding="5dp"
        app:contentPadding="5dp" >
    < RelativeLayout
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_margin="5dp"
            android:layout_height="wrap_content">
        <ImageView
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:layout_centerVertical="true"
                android:src="@drawable/ic_kotlin_logo"
        />
        <TextView android:id="@+id/text_item"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:padding="5dp"
                  android:layout_marginLeft="54dp"
                  android:textSize="18sp"
                  android:textColor="#9C27B0"
                  android:layout_centerVertical="true"

        / >

   </RelativeLayout>
</androidx.cardview.widget.CardView>