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

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

Output

Tutorialwing Kotlin Dynamic DatePicker Output

Getting Started

We can define android DatePicker widget as below –

DatePicker is a widget that display view to select any date.

Now, how do we use DatePicker in android application ?

Before we move ahead, we need to setup for viewBinding to access DatePicker 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 DatePicker 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">DynamicDatePicker</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 xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="10dp"
    android:gravity="center"
    android:orientation="vertical">

    <LinearLayout
        android:id="@+id/rootContainer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

    </LinearLayout>

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="40dp" />

</LinearLayout>

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

4. Create Android DatePicker programmatically in Kotlin

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

package com.tutorialwing.dynamicdatepicker

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.ViewGroup
import android.widget.DatePicker
import android.widget.LinearLayout
import android.widget.Toast
import com.tutorialwing.dynamicdatepicker.databinding.ActivityMainBinding
import java.util.*

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)

		setupDatePicker()
	}

	private fun setupDatePicker() {
		val datePicker = DatePicker(this)
		val layoutParams = LinearLayout.LayoutParams(
			ViewGroup.LayoutParams.MATCH_PARENT,
			ViewGroup.LayoutParams.MATCH_PARENT
		)
		layoutParams.setMargins(10, 10, 10, 10)
		datePicker.layoutParams = layoutParams

		binding.rootContainer.addView(datePicker)

		val today = Calendar.getInstance()
		datePicker.init(
			today.get(Calendar.YEAR), today.get(Calendar.MONTH), today.get(Calendar.DAY_OF_MONTH)

		) { view, year, monthOfYear, dayOfMonth ->
			val month = monthOfYear + 1
			val msg = "Selected Date is $dayOfMonth/$month/$year"
			Toast.makeText(this@MainActivity, msg, Toast.LENGTH_SHORT).show()

			binding.textView.text = msg
			binding.textView.visibility = View.VISIBLE
		}
	}
}

We have defined datePicker programmatically in kotlin file (i.e. in MainActivity.kt file) in the application. Then, we have set layout params and margin in it. Then, we have added this datePicker widget in the linearLayout. After that, we have set listener in datePicker to set the selected date as text in the textView.

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

Tutorialwing Kotlin Dynamic DatePicker Output

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

Set Id of DatePicker

Follow steps below to set id of DatePicker 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="datePicker_ID" />
  </resources>
  

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

  datePicker.id = R.id.datePicker_ID  // DatePicker
  

  Here, we have set id of DatePicker using property access syntax – datePicker.id

Learn to Set ID of DatePicker Using XML Attribute

Set Width and Height of DatePicker

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

datePicker.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 DatePicker 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 DatePicker Using XML Attribute

Set Padding of DatePicker

Follow steps below to set padding of DatePicker 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 DatePicker dynamically, in MainActivity.kt file, as –

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

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

Learn to Set Padding of DatePicker Using XML Attribute

Set Margin of DatePicker

Follow steps below to set margin of DatePicker 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 DatePicker 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)
  datePicker.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 DatePicker.

Learn to Set Margin of DatePicker Using XML Attribute

Set Background of DatePicker

Follow steps below to set background of DatePicker 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 DatePicker dynamically, in MainActivity.kt file, as –

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

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

Learn to Set Background of DatePicker Using XML Attribute

Set Visibility of DatePicker

We can set visibility of DatePicker programmatically as –

datePicker.visibility = View.VISIBLE

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

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