Kotlin: Start another activity | Phaisarn Sutheebanjard

เมื่อสร้างโปรเจ็กส์ใหม่ขึ้นมาจะมี Activity หลักชื่อ MainActivity
เราจะสร้าง Activity เพิ่มขึ้นมาใหม่ชื่อ SecondActivity

การทำงานคือที่ MainActivity จะมีปุ่มไว้กดเรียก SecondActivity
และเมื่อถูกเรียกจะแสดงข้อความ “Second Activity”

ภาพที่ 3 มีการใส่ navigatoin ที่ AndroidManifest.xml

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="callSecondActivity"
        android:text="Call Second Activity" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

tools:context=".MainActivity">

<Button

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:onClick="callSecondActivity"

android:text="Call Second Activity" />

</LinearLayout>

MainActivity.kt

package com.phaisarn.myapplication

import android.content.Intent
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View

class MainActivity : AppCompatActivity() {

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

    /** Called when the user taps the Send button */
    fun callSecondActivity(view: View) {
        val intent = Intent(this, SecondActivity::class.java).apply {}
        startActivity(intent)
    }
}

package com.phaisarn.myapplication

import android.content.Intent

import android.support.v7.app.AppCompatActivity

import android.os.Bundle

import android.view.View

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

}

/** Called when the user taps the Send button */

fun callSecondActivity(view: View) {

val intent = Intent(this, SecondActivity::class.java).apply {}

startActivity(intent)

}

activity_second.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".SecondActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Second Activity"
        android:textSize="18sp" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

tools:context=".SecondActivity">

<TextView

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Second Activity"

android:textSize="18sp" />

</LinearLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.phaisarn.myapplication">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".SecondActivity"
            android:parentActivityName=".MainActivity"></activity>
    </application>

</manifest>

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.phaisarn.myapplication">

<application

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:roundIcon="@mipmap/ic_launcher_round"

android:supportsRtl="true"

android:theme="@style/AppTheme">

<intent-filter>

</intent-filter>

</activity>

<activity

android:name=".SecondActivity"

android:parentActivityName=".MainActivity"></activity>

</application>

</manifest>

บรรทัดที่ 21 : ใส่ navigation หรือลูกศรย้อนกลับไปที่ MainActivity