To demonstrate ClipBoardManager

MainActivity.kt

import android.content.*
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.os.Build
import android.support.annotation.RequiresApi
import kotlinx.android.synthetic.main.activity_main.*
import android.widget.EditText


class MainActivity : AppCompatActivity() {


    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)


        val clipboardManager = getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager

        copy_button.setOnClickListener {
            val editText1Text = editText1.text.toString()

            val mClip = ClipData.newPlainText("text", editText1Text)
            clipboardManager.primaryClip = mClip
        }

        paste_button.setOnClickListener {
            val editText2 = findViewById<EditText>(R.id.editText2)

               val clipBoardText = clipboardManager.primaryClip!!.getItemAt(0).text
               editText2.setText(clipBoardText)
        }

    }


}