Kotlin is a language and used for avoid null pointer exception
kotlin has defaultly uses lambadas for concise event handling code
Kotlin is a safer and more concise code for writing
Kotlin is a modern and it reduces the number of lines code in mobile application development
Here we can see the how the activity
MainActivity[MainActivity.kt
package com.androidfeeders.kotlinactivitychange
import android.content.Intent
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.View
import android.widget.Button
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*
class MainActivity : AppCompatActivity(), View.OnClickListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
//First Button Onclick Listener
activitychange1.setOnClickListener(this)
//Second Button Onclick Listener
val btn_Second_click_me = findViewById(R.id.activitychange2) as Button
btn_Second_click_me.setOnClickListener{
val intent = Intent(applicationContext, SecondActivity::class.java)
startActivity(intent)
}
}
override fun onClick(p0: View?) {
val intent = Intent(applicationContext, FirstActivity::class.java)
startActivity(intent)
}
}
PasswordHelper[FirstActivity.kt]
package com.androidfeeders.kotlinactivitychange
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
class FirstActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.first_activity)
}
}
PasswordHelper[SecondActivity.kt]
package com.androidfeeders.kotlinactivitychange
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
class SecondActivity: AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.second_activity)
}
}
Layout Resource[activity_main.xml]
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/colorPrimaryDark"
android:fontFamily="cursive"
android:text="@string/app_name"
android:textAlignment="center"
android:textColor="@android:color/white"
android:textSize="30sp"
android:textStyle="bold"
android:layout_marginTop="10dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
<Button
android:id="@+id/activitychange1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="First Activity"
android:layout_marginLeft="40dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
app:layout_constraintTop_toTopOf="@+id/textView" />
<Button
android:id="@+id/activitychange2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Second Activity"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="10dp"
android:layout_marginTop="10dp"
app:layout_constraintTop_toTopOf="@+id/textView"
app:layout_constraintLeft_toRightOf="@+id/activitychange1"
android:layout_marginLeft="10dp" />
</android.support.constraint.ConstraintLayout>
Layout Resource[first_actviity.xml]
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="@android:color/holo_green_light"
android:layout_height="match_parent">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="cursive"
android:text="@string/activity_one"
android:textAlignment="center"
android:textColor="@android:color/white"
android:textSize="30sp"
android:textStyle="bold"
android:layout_marginTop="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
</android.support.constraint.ConstraintLayout>t;
Layout Resource[second_activity.xml]
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="@android:color/holo_blue_bright"
android:layout_height="match_parent">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="cursive"
android:text="@string/activity_two"
android:textAlignment="center"
android:textColor="@android:color/white"
android:textSize="30sp"
android:textStyle="bold"
android:layout_marginTop="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
/>
</android.support.constraint.ConstraintLayout>
Gradle Scripts~build.gradle[Module:app]
apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
android {
compileSdkVersion 28
defaultConfig {
applicationId "com.androidfeeders.kotlinactivitychange"
minSdkVersion 15
targetSdkVersion 28
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation"org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'
implementation 'com.android.support.constraint:constraint-layout:1.1.2'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
Gradle Scripts~build.gradle[Project:BaseAdapterSample]
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
ext.kotlin_version = '1.2.41'
repositories {
google()
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.1'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$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
}
Resource[strings.xml]
<resources>
<string name="app_name">KotlinActivityChange</string>
<string name="activity_one">First Actvity</string>
<string name="activity_two">Second Activity</string>
</resources>
manifests
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.androidfeeders.kotlinactivitychange">
<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=".FirstActivity" android:label="@string/activity_one"/>
<activity android:name=".SecondActivity" android:label="@string/activity_two"/>
</application>
</manifest>
I started to learn android and Kotlin and iOS and Hybrid application and i cant code IOS very well. But i love more interesting to code and finding new developer minds who are join to me You're welcome to keep on using my website.Instead, you can join our FB page for developer comments and post there: https://www.facebook.com/ramasamy.m.779 Best wishes :) Ramasamy(Software Developer)
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Kotlin and React native example too
Ramasamy
5 min agoKotlin and React native example too
ReplyRamasamy
5 min agoKotlin and React native example too
ReplyRamasamy
5 min agoKotlin and React native example too
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