Add and Remove Views in Android Dynamically in Kotlin?

Kotlin Apps/ApplicationsMobile Development

This example demonstrates how to Add and Remove Views in Android Dynamically in Kotlin.

Step 1 − Create a new project in Android Studio, go to File ? New Project and fill all required details to create a new project.

Step 2  − Add the following code to res/layout/activity_main.xml.

Example

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:id="@+id/parent_linear_layout"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:layout_margin="5dp"
   android:orientation="vertical"
   tools:context=".MainActivity">
   <LinearLayout
      android:layout_width="match_parent"
      android:layout_height="50dp"
      android:orientation="horizontal">
      <EditText
         android:layout_width="0dp"
         android:layout_height="match_parent"
         android:layout_weight="5"
         android:inputType="phone" />
      <Spinner
         android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_weight="3"
         android:entries="@array/types"
         android:gravity="right" />
      <Button
         android:layout_width="0dp"
         android:layout_height="40dp"
         android:layout_weight="1"
         android:background="@android:drawable/ic_delete"
        android:onClick="onDelete" />
   </LinearLayout>
   <Button
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_gravity="center"
       android:onClick="onAddField"
       android:text="Add Field"
       android:textColor="@android:color/background_dark" />
</LinearLayout>

Step 3 − Add the following code to src/MainActivity.kt

Example

import android.content.Context
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.widget.LinearLayout
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
   private var parentLinearLayout: LinearLayout? = null
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      parentLinearLayout = findViewById(R.id.parent_linear_layout)
   }
   fun onDelete(view: View) {
      parentLinearLayout!!.removeView(view.parent as View)
   }
   fun onAddField(view: View) {
      val inflater =
      getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
      val rowView: View = inflater.inflate(R.layout.field, null)
      parentLinearLayout!!.addView(rowView, parentLinearLayout!!.childCount - 1)
   }
}

Step 4 − Create a new Layout Resource file (field.xml) and add the following code −

Example

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="50dp"
   android:orientation="horizontal">
   <EditText
      android:id="@+id/number_edit_text"
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_weight="5"
      android:inputType="phone" />
   <Spinner
      android:id="@+id/type_spinner"
      android:layout_width="0dp"
      android:layout_height="wrap_content"
      android:layout_weight="3"
      android:entries="@array/types"
      android:gravity="right" />
   <Button
       android:id="@+id/delete_button"
       android:layout_width="0dp"
       android:layout_height="40dp"
       android:layout_weight="1"
       android:background="@android:drawable/ic_delete"
       android:onClick="onDelete" />
</LinearLayout>

Step 5 − Open res/values/strings.xml and add the following code −

Example

<resources>
<string name="app_name">YourAppName</string>
   <string-array name="types">
      <item>Mobile</item>
      <item>Office</item>
      <item>Home</item>
   </string-array>
</resources>

Step 6 − Add the following code to androidManifest.xml

example

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.q1">
   <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>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run   icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen

raja
Published on 23-May-2020 12:54:30
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