Hello Readers! In this post, we are going to learn about how to use android numberPicker programmatically in kotlin in the application. We will also learn how to add numberPicker to linearLayout programmatically in android application.

Output

Tutorialwing Kotlin Dynamic NumberPicker Integer Output

Tutorialwing Kotlin Dynamic NumberPicker String Output

Getting Started

At first, we will create android project. Then, we will create and use numberPicker programmatically in kotlin file.

1. Creating New Project in Kotlin

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

Now, we will modify xml and kotlin file to use numberPicker dynamically.

2. Modify Values Folder

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

<resources>
	<string name="app_name">DynamicNumberPicker</string>
</resources>

3. Modify Layout Folder

Open res/layout/activity_main.xml file. Then, 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:orientation="horizontal">

</LinearLayout>

In activity_main.xml file, we have defined linearLayout, with id rootContainer, that will act as container for the numberPicker created dynamically in the application.

NumberPicker widget can accepts two types of data. They are –
a. Integer values.
b. Array of String values.

Now, we will see how we can provide each data types to the numberPicker.

4.1 Create Android NumberPicker Programmatically / Dynamically in Kotlin And Show Integer Values

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

package com.tutorialwing.dynamicnumberpicker

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.NumberPicker
import android.widget.Toast

class MainActivity : AppCompatActivity() {

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

        val numberPicker = NumberPicker(this)
        val layoutParams = LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        numberPicker.layoutParams = layoutParams

        numberPicker.minValue = 0
        numberPicker.maxValue = 10
        numberPicker.wrapSelectorWheel = true
        numberPicker.setOnValueChangedListener { picker, oldVal, newVal ->
            val text = "Changed from $oldVal to $newVal"
            Toast.makeText(this@MainActivity, text, Toast.LENGTH_SHORT).show()
        }

        val linearLayout = findViewById<LinearLayout>(R.id.rootContainer)
        linearLayout?.addView(numberPicker)
    }
}

Here, We have created numberPicker programmatically in kotlin file. After that, we have configured numberPicker to show range of integer values. minValue is used to set minimum value in range. maxValue is used to set maximum value in range. wrapSelectorWheel is used to specify whether we want to show start value of range if we have reached to end. We have also defined a listener that displays a toast message whenever there is change in value selection in numberPicker. Finally, we have added numberPicker widget in linearLayout.

4.2 Create Android NumberPicker Programmatically / Dynamically in Kotlin And Show Array Of String Values

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

package com.tutorialwing.dynamicnumberpicker

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.NumberPicker
import android.widget.Toast

class MainActivity : AppCompatActivity() {

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

        val numberPicker = NumberPicker(this)
        val layoutParams = LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT)
        numberPicker.layoutParams = layoutParams

        val values = arrayOf("Blue", "Magenta", "Yellow", "Red", "Pink", "White", "Green", "Violet")
        numberPicker.minValue = 0
        numberPicker.maxValue = values.size - 1
        numberPicker.displayedValues = values
        numberPicker.wrapSelectorWheel = true
        numberPicker.setOnValueChangedListener { picker, oldVal, newVal ->
            val text = "Changed from " + values[oldVal] + " to " + values[newVal]
            Toast.makeText(this@MainActivity, text, Toast.LENGTH_SHORT).show()
        }

        val linearLayout = findViewById<LinearLayout>(R.id.rootContainer)
        linearLayout?.addView(numberPicker)
    }
}

Here, we have created numberPicker programmatically in kotlin file. After that, we have configured it to show array of string values. Variable values represents array of string values that we will provide to numberPicker. We have provided data to the numberPicker using displayedValues attribute.

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 src/main/AndroidManifest.xml file is –

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.tutorialwing.dynamicnumberpicker"
		  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 Creating Android NumberPicker Programmatically in Kotlin.