In this article, we will learn how to create android Checkbox programmatically in Kotlin. We will go through various steps that explains how to create Checkbox and add it in kotlin file, use different attributes to customise it etc. in any android application. For example, how to set text in Checkbox programmatically, how to set id of Checkbox, how to capitalise text of Checkbox dynamically etc. We will get answer to all such questions in this post.

Learn to use Different Attributes of Checkbox in XML File to Customize it.

Output

Tutorialwing Android Kotlin checkbox Output

Getting Started

We can define android Checkbox widget as below –

A checkbox is a specific type of two-states button that can be either checked or unchecked.

Now, how do we use Checkbox in android application ?

Before we move ahead, we need to setup for viewBinding to access Checkbox in Kotlin file without using findViewById() method.

Setup ViewBinding

Add viewBinding true in app/build.gradle file.

 
 android { 
 	// OTHER CODE... 
 	buildFeatures { 
 		viewBinding true 
 	} 
 } 
 

Now, set content in activity using view binding.
Open MainActivity.kt file and write below code in it.

 
 class MainActivity : AppCompatActivity() { 
 	
 	private lateinit var binding: ActivityMainBinding 
 	
 	override fun onCreate(savedInstanceState: Bundle?) { 
 		super.onCreate(savedInstanceState) 
 		binding = ActivityMainBinding.inflate(layoutInflater) 
 		val view = binding.root 
 		setContentView(view) 
 	} 
 } 
 

Now, we can access view in Kotlin file without using findViewById() method.

Since we have a new project, we will modify the xml and class file to use Checkbox programmatically in kotlin. Please follow the steps below.

2. Modify Values Folder

Open res/values/strings.xml file. Add below code into it.

<resources>
    <string name="app_name">DynamicCheckboxUsingKotlin</string>
    <string name="check_it">Check it</string>
</resources>

Other values folders have not been changed. So, we are not going to mention it here.

3. Modify Layout Folder

Open res/layout/activity_main.xml file. Add below code into it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:id="@+id/rootContainer"
    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">

</LinearLayout>

Note that LinearLayout has id rootLayout. In Kotlin file, we will create Checkbox Dynamically and add it into this LinearLayout having id rootLayout.

4. Create Android Checkbox programmatically in Kotlin

Open src/main/java/com.tutorialwing.dynamiccheckbox/MainActivity.kt file. Then, add below code into it.

package com.tutorialwing.dynamiccheckbox

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.ViewGroup
import android.widget.CheckBox
import android.widget.LinearLayout
import android.widget.Toast
import com.tutorialwing.dynamiccheckbox.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

	private lateinit var binding: ActivityMainBinding

	override fun onCreate(savedInstanceState: Bundle?) {
		super.onCreate(savedInstanceState)
		binding = ActivityMainBinding.inflate(layoutInflater)
		val view = binding.root
		setContentView(view)

		addCheckbox()
	}

	private fun addCheckbox() {
		// Create CheckBox
		val checkBox = CheckBox(this)
		checkBox.setHint(R.string.check_it)
		checkBox.layoutParams = LinearLayout.LayoutParams(
			ViewGroup.LayoutParams.MATCH_PARENT,
			ViewGroup.LayoutParams.WRAP_CONTENT
		)
		checkBox.setPadding(20, 20, 20, 20)
		checkBox.setOnCheckedChangeListener { buttonView, isChecked ->
			val msg = "You have " + (if (isChecked) "checked" else "unchecked") + " this Checkbox."
			Toast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show()
		}

		// Add CheckBox to LinearLayout
		binding.rootContainer.addView(checkBox)
	}
}

Finally, when you run the application, you will get output as shown above.
// Checkbox OUTPUT

Now, Let’s check how to use different attributes of Checkbox to customize it dynamically –

Set Id of Checkbox

Follow steps below to set id of Checkbox programmatically –

• Create ids.xml file in res/values folder. Then, add below code into it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <item type="id" name="checkbox_ID" />
  </resources>
  

• Now, we can set id of Checkbox dynamically, in MainActivity.kt file, as –

  checkBox.id = R.id.checkbox_ID  // Checkbox
  

  Here, we have set id of Checkbox using property access syntax – checkBox.id

Learn to Set ID of Checkbox Using XML Attribute

Set Width and Height of Checkbox

We use layoutParams to set width and height of any View programmatically. In this article, we have added Checkbox in LinearLayout. So, we will define LayoutParams as below –

checkBox.layoutParams = LinearLayout.LayoutParams(
	ViewGroup.LayoutParams.WRAP_CONTENT,
	ViewGroup.LayoutParams.WRAP_CONTENT
)

Here, we have set width and height as WRAP_CONTENT. Some of possible values for width and height are –

• WRAP_CONTENT: Sets value of width or height depending on text inside it.
• MATCH_PARENT: Sets value of width of height depending on width or height of parent layout . i.e. width or height of Checkbox will be same as width or height of parent layout.
• Fixed Value: Sets width or height as per value provided.

Learn to Set Width or Height of Checkbox Using XML Attribute

Set Padding of Checkbox

Follow steps below to set padding of Checkbox Dynamically –

• If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <dimen name="text_padding">16dp</dimen>
  </resources>
  

• Now, we can set padding of Checkbox dynamically, in MainActivity.kt file, as –

  val padding = resources.getDimension(R.dimen.text_padding).toInt()
  checkBox.setPadding(padding, padding, padding, padding)
  

  Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, set padding of Checkbox using setPadding() method.

Learn to Set Padding of Checkbox Using XML Attribute

Set Margin of Checkbox

Follow steps below to set margin of Checkbox Dynamically –

• If there is no dimens.xml file, create dimens.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <dimen name="text_margin">16dp</dimen>
  </resources>
  

• Now, we can set margin of Checkbox dynamically, in MainActivity.kt file, as –

  val margin = resources.getDimension(R.dimen.text_margin).toInt()
  val layoutParams = LinearLayout.LayoutParams(
  	ViewGroup.LayoutParams.WRAP_CONTENT,
  	ViewGroup.LayoutParams.WRAP_CONTENT
  )
  layoutParams.setMargins(margin, margin, margin, margin)
  checkBox.layoutParams = layoutParams
  

  Here, we have accessed dimension defined in dimens.xml using getDimension() method. Then, we have defined layoutParams, set margin to layoutParams. After that, set layoutParams to CheckBox.

Learn to Set Margin of Checkbox Using XML Attribute

Set Background of Checkbox

Follow steps below to set background of Checkbox programmatically –

• If there is no colors.xml file, create colors.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <color name="purple_200">#FFBB86FC</color>
  </resources>
  

• Now, we can set background of Checkbox dynamically, in MainActivity.kt file, as –

  val color = ContextCompat.getColor(this, R.color.purple_200)
  checkBox.setBackgroundColor(color)
  

  Here, we used setBackgroundColor() method to set background color in checkBox.

Learn to Set Background of Checkbox Using XML Attribute

Set Visibility of Checkbox

We can set visibility of Checkbox programmatically as –

checkBox.visibility = View.VISIBLE

Here, we have set visibility of Checkbox using checkBox.visibility attribute. Visibility can be of three types – gone, visible and invisible.
Learn to Set Visibility of Checkbox Using XML Attribute

Set Text of Checkbox

Follow steps below to set text of Checkbox programmatically –

• If there is no strings.xml file, create strings.xml file in res/values folder. Then, add below code in it –

  <resources>
      <string name="click_on_me">Click on me</string>
  </resources>
  

• Now, we can set text of Checkbox dynamically, in MainActivity.kt file, as –

  checkBox.text = getString(R.string.click_on_me)
  

  Here, we used checkBox.text to set text in checkBox.

Learn to Set Text of Checkbox Using XML Attribute

Set Color of Text of Checkbox

Follow steps below to set color of text of Checkbox programmatically in Kotlin –

• If there is no colors.xml file, create colors.xml file in res/values folder. Then, add below code in it –

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
      <color name="black">#FF000000</color>
  </resources>
  

• Now, we can set color of text of Checkbox dynamically, in MainActivity.kt file, as –

  val textColor = ContextCompat.getColor(this, R.color.black)
  checkBox.setTextColor(textColor)
  

  Here, we used setTextColor() method to set color of Checkbox of checkBox.

Learn to Set Color of Checkbox Using XML Attribute

Set Gravity of Checkbox

We can set gravity of text of Checkbox programmatically in Kotlin as –

checkBox.gravity = Gravity.CENTER

Here, we have set gravity of Checkbox as center. So, all the text of Checkbox will be center aligned.
We can also apply multiple gravity values as –

checkBox.gravity = Gravity.CENTER_HORIZONTAL or Gravity.BOTTOM

Here, we have applied multiple gravity values, in Kotlin, to CheckBox. In above case, text will be aligned as horizontally centered to bottom.
Learn to Set Margin of Checkbox Using XML Attribute

Set Text in Uppercase or Lowercase

Follow steps below to set text in uppercase or lowercase programmatically as –

• Set Text in Uppercase

  We use checkBox.isAllCaps attributes to set text in uppercase or normal. If it is true, text will be set in uppercase.

  checkBox.text = "Hello Tutorialwing"
  checkBox.isAllCaps = true
  

  In Above case, “Hello Tutorialwing” will be set in Uppercase to CheckBox. So, text will be “HELLO TUTORIALWING”.

• By default, isAllCaps is false. So, whatever is written, text will be set as it is. For example,

  checkBox.text = "Hello Tutorialwing"
  checkBox.isAllCaps = false. // By default it is false. Written here for example.
  

  Above code will set text, “Hello Tutorialwing”, to Checkbox without changing it to Uppercase.

  Actually, if isAllCaps is false, text is set as it is. It neither changes to uppercase nor lowercase.

  How do we set text in lowercase?

  Answer –

  • In xml file – write all the text in lowercase.
  • In kotlin file – take text as string. Then, convert it in lowercase. Then, set it to checkBox.

Learn to Set Text in Uppercase or Lowercase Using XML Attribute

Set Size of Text in Checkbox

Follow steps below to set size of Checkbox programmatically using checkBox.textSize attribute –

• Open res/values/dimens.xml file. Then, add below font-size in it –

  <dimen name="text_size">16sp</dimen>
  

• Now, using checkBox.textSize attribute, we can set size of text dynamically as –

  checkBox.textSize = resources.getDimension(R.dimen.text_margin)
  

Learn to Set Size of Text in Checkbox Using XML Attribute

Set Style (Bold/italic) of Text in Checkbox

We can set textStyle of Checkbox programmatically as –

checkBox.typeface = Typeface.DEFAULT_BOLD;

In above case, we have set textStyle as bold. So, text of Checkbox will be displayed as bold letters.

If we want to preserve previous textStyle too, we can do it as –

checkBox.setTypeface(checkBox.typeface, Typeface.BOLD);

Learn to Set Typeface of Checkbox Using XML Attribute

Set Letter Spacing of Text in Checkbox

Follow steps below to set letter spacing of Checkbox programmatically –

• Open res/values/dimens.xml file. Then, add below dimension in it –

  <dimen name="text_letter_spacing">1dp</dimen>
  

• We use checkBox.letterSpacing attribute to set letter spacing of Checkbox as below –

  checkBox.letterSpacing = resources.getDimension(R.dimen.text_letter_spacing)
  

Learn to Set Letter Spacing of Checkbox Using XML Attribute

That’s end of tutorial on Checkbox Programmatically in Kotlin With Example.