안드로이드 액티비티 전환

1. Second Activity.xml, Second Activity.kt 생성

//SecondActivity.kt 코드

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

2. MainActivity에 버튼을 만듬

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Second Activity"
        android:onClick="SecondActivity" <!-- 버튼 클릭시 SecondActivity function 실행 -->
        />

3. MainActivity.kt 코드

class MainActivity : AppCompatActivity() {

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

    fun SecondActivity(v: View) {
        val intent = Intent(this, SecondActivity::class.java)
        startActivity(intent)
    }
}

4. AndroidManifest.xml에 아래 코드를 추가 -> 해당 작업을 하지 않으면 앱이 팅김

<application>
	...
	<activity android:name=".SecondActivity"></activity>
	...
</application>