Kotlin Android start new Activity

Question

I want to start another activity on Android but I get this error:

Please specify constructor invocation; classifier \'Page2\' does not have a companio

Answer 1

another simple way of navigating to another activity is

Intent(this, CodeActivity::class.java).apply {
                    startActivity(this)
                }

Answer 2

From activity to activity

val intent = Intent(this, YourActivity::class.java)
startActivity(intent)

From fragment to activity

val intent = Intent(activity, YourActivity::class.java)
startActivity(intent)

Answer 3

To start a new Activity ,

startActivity(Intent(this@CurrentClassName,RequiredClassName::class.java)

So change your code to :

class MainActivity : AppCompatActivity() {

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

    fun buTestUpdateText2 (view: View) {
        startActivity(Intent(this@MainActivity,ClassName::class.java))

        // Also like this 

        val intent = Intent(this@MainActivity,ClassName::class.java)
        startActivity(intent)
    }

Answer 4

Well, I found these 2 ways to be the simplest of all outcomes:

Way #1:

accoun_btn.setOnClickListener {
            startActivity(Intent(this@MainActivity, SecondActivity::class.java))
        }

Way#2: (In a generic way)

    accoun_btn.setOnClickListener {
        startActivity<SecondActivity>(this)
    }

    private inline fun <reified T> startActivity(context: Context) {
            startActivity(Intent(context, T::class.java))
        }

Answer 5

You have to give the second argument of class type. You can also have it a little bit more tidy like below.

startActivity(Intent(this, Page2::class.java).apply {
    putExtra("extra_1", value1)
    putExtra("extra_2", value2)
    putExtra("extra_3", value3)
})