Hello Readers! In this post, we are going to learn about android imageView using kotlin in any android application. We will also learn about different attributes of android imageView that can be used to customise this widget.

Output

Tutorialwing Kotlin ImageView Output

Getting Started

Android imageView can be defined as below –

ImageView is subclass of view that displays image. It is also used to handle image tinting and scaling

Different Attributes of Android ImageView Widget

Some of the popular attributes of imageView are –

Some of the popular attributes of ImageButton inherited from View are –

Example of Android ImageView Using Kotlin

At first, we will create android application. Then, we will use imageView using kotlin in the application.

1. Creating New Project in Kotlin

Follow steps below to create new project. Please ignore the steps if you have already created the project.

Since we have a project now, we will modify xml and other files to use imageView using kotlin in the application.

2. Modify values folder

Open res/values/strings.xml file. Then, add below code into it.

<resources>
	<string name="app_name">ImageView</string>
	<string name="this_is_imageview">This is imageView</string>
	<string name="change_image">Change Image</string>
</resources>

3. Use ImageView Widget in xml file

Open src/main/res/layout/activity_main.xml file and add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
	xmlns:android="http://schemas.android.com/apk/res/android"
	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:layout_marginBottom="20dp"
		android:text="@string/change_image"/>

	<ImageView
		android:id="@+id/imageView"
		android:layout_width="80dp"
		android:layout_height="80dp"
		android:contentDescription="@string/this_is_imageview"/>

</LinearLayout>

In activity_main.xml file, we have defined imageView widget. Now, we will access this imageView using kotlin file in the application.

4. Access ImageView Widget in Kotlin file

Open src/main/java/com.tutorialwing.imageview/MainActivity.kt file and add below code into it.

package com.tutorialwing.imageview

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Button
import android.widget.ImageView

class MainActivity : AppCompatActivity() {

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

        val imageView = findViewById<ImageView>(R.id.imageView)

        val imgResId = R.drawable.ic_launcher_background
        var resId = imgResId
        imageView.setImageResource(imgResId)

        val button = findViewById<Button>(R.id.button)
        button?.setOnClickListener {
            resId = if (resId == R.drawable.ic_launcher_background) R.mipmap.ic_launcher else R.drawable.ic_launcher_background
            imageView.setImageResource(resId)
        }
    }
}

We have accessed imageView using kotlin file (i.e. MainActivity.kt file) in the application. Then, we have set an image resource in it. After that, we have set a click listener on button that will change the button in the imageView whenever it is clicked. Similarly, you can perform any operation in imageView.

Since AndroidManifest.xml file is very important in any android application, we are also going to see the content inside this file.

AndroidManifest.xml file

Code inside main/AndroidManifest.xml file is as below.

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

	<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>
	</application>

</manifest>

When we run the program, we will get output as shown above.

That’s end of our tutorial on Android ImageView using Kotlin.