KT: เปลี่ยน Background ของ Button ด้วย Kotlin

ทุกครั้งที่กดปุ่ม ก็จะสลับ Background

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">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="vertical">

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/btn_center_gradient"
            android:padding="15dp"
            android:text="Changing Button"
            android:textColor="#FFFFFF" />
    </LinearLayout>

</android.support.constraint.ConstraintLayout>

<?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">

<LinearLayout

android:layout_width="match_parent"

android:layout_height="match_parent"

android:gravity="center"

android:orientation="vertical">

<Button

android:id="@+id/button"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:background="@drawable/btn_center_gradient"

android:padding="15dp"

android:text="Changing Button"

android:textColor="#FFFFFF" />

</LinearLayout>

</android.support.constraint.ConstraintLayout>

MainActivity.kt

package com.phaisarn.ktapplication

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

        var button_background: Int = 1
        button.setOnClickListener {
            if (button_background == 2) {
                button.setBackgroundResource(R.drawable.btn_center_gradient)
                button_background = 1;
            } else if (button_background == 1) {
                button.setBackgroundResource(R.drawable.btn_oval_gradient)
                button_background = 2;
            }
        }
    }
}

package com.phaisarn.ktapplication

import android.support.v7.app.AppCompatActivity

import android.os.Bundle

import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

setContentView(R.layout.activity_main)

var button_background: Int = 1

button.setOnClickListener {

if (button_background == 2) {

button.setBackgroundResource(R.drawable.btn_center_gradient)

button_background = 1;

} else if (button_background == 1) {

button.setBackgroundResource(R.drawable.btn_oval_gradient)

button_background = 2;

}

drawable/btn_center_gradient.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <gradient
        android:angle="90"
        android:centerColor="#12434c"
        android:endColor="#258191"
        android:startColor="#44e3ff" />
</shape>

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

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

android:shape="rectangle">

<gradient

android:angle="90"

android:centerColor="#12434c"

android:endColor="#258191"

android:startColor="#44e3ff" />

</shape>

drawable/btn_oval_gradient.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <gradient
        android:angle="90"
        android:centerColor="#7a5d28"
        android:endColor="#ad853a"
        android:startColor="#ffc456" />
</shape>

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

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

android:shape="oval">

<gradient

android:angle="90"

android:centerColor="#7a5d28"

android:endColor="#ad853a"

android:startColor="#ffc456" />

</shape>

Phaisarn Sutheebanjard

blog.phaisarn.com

KT: เปลี่ยน Background ของ Button ด้วย Kotlin