ดูไฟล์ต่างๆเมื่อสร้างโปรเจ็กส์ใหม่แบบ Bottom Navigation Activity

• AndroidManifest.xml
• build.gradle (Project: MyApplication)
• build.gradle (Module: app)
• activity_main.xml
• menu/bottom_nav_menu.xml
• strings.xml
• values/dimens.xml
• MainActivity.kt
• ExampleUnitTest.kt

AndroidManifest.xml

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

    <dist:module dist:instant="true"/>

    <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"
                android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

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

</manifest>

build.gradle (Project: MyApplication)

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    ext.kotlin_version = '1.3.31'
    repositories {
        google()
        jcenter()
        
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.4.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

build.gradle (Module: app)

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.0"
    defaultConfig {
        applicationId "com.phaisarn.myapplication"
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'androidx.appcompat:appcompat:1.0.2'
    implementation 'androidx.core:core-ktx:1.0.2'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.2.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

    <TextView
            android:id="@+id/message"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="@dimen/activity_horizontal_margin"
            android:layout_marginLeft="@dimen/activity_horizontal_margin"
            android:layout_marginTop="@dimen/activity_vertical_margin"
            android:text="@string/title_home"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

    <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/nav_view"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginEnd="0dp"
            android:layout_marginStart="0dp"
            android:background="?android:attr/windowBackground"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:menu="@menu/bottom_nav_menu"/>

</androidx.constraintlayout.widget.ConstraintLayout>

menu/bottom_nav_menu.xml

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

    <item
            android:id="@+id/navigation_home"
            android:icon="@drawable/ic_home_black_24dp"
            android:title="@string/title_home"/>

    <item
            android:id="@+id/navigation_dashboard"
            android:icon="@drawable/ic_dashboard_black_24dp"
            android:title="@string/title_dashboard"/>

    <item
            android:id="@+id/navigation_notifications"
            android:icon="@drawable/ic_notifications_black_24dp"
            android:title="@string/title_notifications"/>

</menu>

strings.xml

<resources>
    <string name="app_name">My Application</string>
    <string name="title_home">Home</string>
    <string name="title_dashboard">Dashboard</string>
    <string name="title_notifications">Notifications</string>
</resources>

values/dimens.xml

<resources>
    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
</resources>

MainActivity.kt

package com.phaisarn.myapplication

import android.os.Bundle
import com.google.android.material.bottomnavigation.BottomNavigationView
import androidx.appcompat.app.AppCompatActivity
import android.widget.TextView

class MainActivity : AppCompatActivity() {

    private lateinit var textMessage: TextView
    private val onNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
        when (item.itemId) {
            R.id.navigation_home -> {
                textMessage.setText(R.string.title_home)
                return@OnNavigationItemSelectedListener true
            }
            R.id.navigation_dashboard -> {
                textMessage.setText(R.string.title_dashboard)
                return@OnNavigationItemSelectedListener true
            }
            R.id.navigation_notifications -> {
                textMessage.setText(R.string.title_notifications)
                return@OnNavigationItemSelectedListener true
            }
        }
        false
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val navView: BottomNavigationView = findViewById(R.id.nav_view)

        textMessage = findViewById(R.id.message)
        navView.setOnNavigationItemSelectedListener(onNavigationItemSelectedListener)
    }
}

ExampleUnitTest.kt

package com.phaisarn.myapplication

import org.junit.Test

import org.junit.Assert.*

/**
 * Example local unit test, which will execute on the development machine (host).
 *
 * See [testing documentation](http://d.android.com/tools/testing).
 */
class ExampleUnitTest {
    @Test
    fun addition_isCorrect() {
        assertEquals(4, 2 + 2)
    }
}