listener - Android - How to achieve setOnClickListener in Kotlin?

Question

I wanted to know that how we set basic onClickListener in Kotlin for Android Development.

Answer 1

There are five ways to use SetOnClickListener:

First:

button.setOnClickListener {
    // Do some work here
}

Second:

button.setOnClickListener(object : View.OnClickListener {
    override fun onClick(view: View?) {
        // Do some work here
    }

})

Third:

button.setOnClickListener(View.OnClickListener { view ->
    // Do some work here
})

Forth:

class MainActivity : AppCompatActivity(), View.OnClickListener{

    lateinit var button : Button

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        button = findViewById(R.id.button1)
        button.setOnClickListener(this)
    }

    override fun onClick(view: View?) {
        when(view?.id){
            R.id.button1->{
                // do some work here
            }
        }
    }
}

Fifth:

class MainActivity : AppCompatActivity(){

    lateinit var button : Button

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        button = findViewById(R.id.button1)
        button.setOnClickListener(listener)
    }

    val listener= View.OnClickListener { view ->
        when (view.getId()) {
            R.id.button1 -> {
                // Do some work here
            }
        }
    }
}

Cheers!