画面遷移（簡易）

Kotlin

MainActivity.kt

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

        val button = findViewById<Button>(R.id.bt_next)
        val listener = Hellolistener()
        button.setOnClickListener(listener)
    }

    private inner class HelloListener : View.OnClickListener {
        override fun onClick(view: View) {
            val intent = Intent(this, SecondActivity::class.java)
            intent.putExtra("EXTRA_MESSAGE", "HELLO, SECOND_ACTIVITY")
            startActivity(intent)
        }
    }
}

SecondActivity.kt

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

        val message = intent.getStringExtra("EXTRA_MESSAGE")
        val tvMsg = findViewById<TextView>(R.id.tv_msg)
        tvMsg.text = message
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" >
    <Button
        android:id="@+id/bt_next"
        android:text="GO TO SECOND ACTIVITY" />
</LinearLayout>

activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/tv_msg"
        android:text="セカンドアクティビティ" />
</LinearLayout>

manifests/AndroidManifest.xml

SecondActivityをマニフェストに登録します。（※登録しないとボタンをクリックした後にアプリが終了してしまいます。）

<application
    android:allowBackup="true"
    android:label="@string/app_name"
    android:theme=""@style/Theme.MyApplication">

    <activity android:name=".SecondActivity" />　<---この部分を追加！
    <activity android:name=".MainActivity" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
BACK