How to load an URL inside a WebView using Android Kotlin?

Question

I am new to both Android and Kotlin.

Anyone can help me to load an URL in a webView?

I just want to load the URL and view the webpage when the app is open.

Answer 1

1.activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout  xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.kotlinwebview.MainActivity">   <WebView     android:id="@+id/webview"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:ignore="MissingConstraints"     tools:layout_editor_absoluteX="8dp"     tools:layout_editor_absoluteY="8dp" />      </android.support.constraint.ConstraintLayout> 

2.MainActivity.kt

class MainActivity : AppCompatActivity() {      private lateinit var webView: WebView      override fun onCreate(savedInstanceState: Bundle?) {         super.onCreate(savedInstanceState)         setContentView(R.layout.activity_main)         webView = findViewById(R.id.webview)         webView.settings.setJavaScriptEnabled(true)          webView.webViewClient = object : WebViewClient() {             override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {                 view?.loadUrl(url)                 return true             }         }         webView.loadUrl("https://www.google.co.in/")     } } 

Answer 2

Here is the complete working code to load a website in android webView. Just create a new project from the android studio and use the following code to load the web view. Just change the URL you want to load it in the web view.

• It will load a website in the webview
• It will check internet connection availability
• If there is no internet ask the user to enable WiFi from the snack bar message
• Loads the progress until website loads
• Handles the error if something went wrong while loading website
• Handles the back button press cases
• Handles exit from the app confirmation with toast

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/rootView"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity">      <WebView         android:id="@+id/webView"         android:layout_width="match_parent"         android:layout_height="match_parent"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toTopOf="parent" />      <TextView         android:id="@+id/infoTV"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:gravity="center"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintEnd_toEndOf="parent"         app:layout_constraintStart_toStartOf="parent"         app:layout_constraintTop_toTopOf="parent" />  </androidx.constraintlayout.widget.ConstraintLayout> 

MainActivity.kt:

import android.annotation.SuppressLint import android.content.Context import android.content.Intent import android.graphics.Bitmap import android.net.ConnectivityManager import android.net.NetworkCapabilities import android.os.Bundle import android.os.Handler import android.os.Looper import android.provider.Settings import android.util.Log import android.view.KeyEvent import android.webkit.WebResourceError import android.webkit.WebResourceRequest import android.webkit.WebView import android.webkit.WebViewClient import android.widget.Toast import androidx.appcompat.app.AppCompatActivity import com.google.android.material.snackbar.Snackbar import kotlinx.android.synthetic.main.activity_main.*   class MainActivity : AppCompatActivity() {      private var progress: Progress? = null     private var isLoaded: Boolean = false     private var doubleBackToExitPressedOnce = false     private var webURL = "https://www.geeklabs.co.in/" // Change it with your URL      @SuppressLint("SetJavaScriptEnabled")     override fun onCreate(savedInstanceState: Bundle?) {         super.onCreate(savedInstanceState)         setContentView(R.layout.activity_main)         webView.settings.javaScriptEnabled = true         if (!isOnline()) {             showToast(getString(R.string.no_internet))             infoTV.text = getString(R.string.no_internet)             showNoNetSnackBar()             return         }     }      override fun onResume() {         if (isOnline() && !isLoaded) loadWebView()         super.onResume()     }      private fun loadWebView() {         infoTV.text = ""         webView.loadUrl(webURL)         webView.webViewClient = object : WebViewClient() {             override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {                 val url = request?.url.toString()                 view?.loadUrl(url)                 return super.shouldOverrideUrlLoading(view, request)             }              override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {                 setProgressDialogVisibility(true)                 super.onPageStarted(view, url, favicon)             }              override fun onPageFinished(view: WebView?, url: String?) {                 isLoaded = true                 setProgressDialogVisibility(false)                 super.onPageFinished(view, url)             }              override fun onReceivedError(view: WebView, request: WebResourceRequest, error: WebResourceError) {                 isLoaded = false                 val errorMessage = "Got Error! $error"                 showToast(errorMessage)                 infoTV.text = errorMessage                 setProgressDialogVisibility(false)                 super.onReceivedError(view, request, error)             }         }     }      override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {         if (event.action == KeyEvent.ACTION_DOWN) {             if (keyCode == KeyEvent.KEYCODE_BACK) {                 if (webView.canGoBack()) {                     webView.goBack()                 } else {                     showToastToExit()                 }                 return true             }         }         return super.onKeyDown(keyCode, event)     }      private fun showToastToExit() {         when {             doubleBackToExitPressedOnce -> {                 onBackPressed()             }             else -> {                 doubleBackToExitPressedOnce = true                 showToast(getString(R.string.back_again_to_exit))                 Handler(Looper.myLooper()!!).postDelayed({ doubleBackToExitPressedOnce = false }, 2000)             }         }     }      private fun setProgressDialogVisibility(visible: Boolean) {         if (visible) progress = Progress(this, R.string.please_wait, cancelable = true)         progress?.apply { if (visible) show() else dismiss() }     }      private fun isOnline(): Boolean {         val connectivityManager =                 getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager         val capabilities =                 connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)         if (capabilities != null) {             when {                 capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> {                     Log.i("Internet", "NetworkCapabilities.TRANSPORT_CELLULAR")                     return true                 }                 capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> {                     Log.i("Internet", "NetworkCapabilities.TRANSPORT_WIFI")                     return true                 }                 capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> {                     Log.i("Internet", "NetworkCapabilities.TRANSPORT_ETHERNET")                     return true                 }             }         }         return false     }      private fun showToast(message: String) {         Toast.makeText(this, message, Toast.LENGTH_SHORT).show()     }      private fun showNoNetSnackBar() {         val snack = Snackbar.make(rootView, getString(R.string.no_internet), Snackbar.LENGTH_INDEFINITE)         snack.setAction(getString(R.string.settings)) {             startActivity(Intent(Settings.ACTION_WIFI_SETTINGS))         }         snack.show()     } } 

Progress.kt:

import android.app.AlertDialog import android.app.Dialog import android.content.Context import android.view.LayoutInflater import android.view.View import android.widget.TextView import androidx.annotation.StringRes  class Progress constructor(     context: Context?,     @StringRes private val titleRes: Int,     cancelable: Boolean = false ) {      private var view: View? = null     private var builder: AlertDialog.Builder     private var dialog: Dialog      init {         view = LayoutInflater.from(context).inflate(R.layout.progress, null)         view?.findViewById<TextView>(R.id.text)?.setText(titleRes)         builder = AlertDialog.Builder(context)         builder.setView(view)         dialog = builder.create()         dialog.setCancelable(cancelable)     }      fun setProgressMessage(@StringRes titleRes: Int) {         view?.findViewById<TextView>(R.id.text)?.setText(titleRes)     }      fun show() {         dialog.show()     }      fun dismiss() {         if (dialog.isShowing) {             dialog.dismiss()         }     }      fun setProgressDialogVisibility(isVisible: Boolean) {      } } 

pregress.xml:

<?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/linearLayout"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:gravity="center_vertical">      <ProgressBar         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_margin="16dp" />      <TextView         android:id="@+id/text"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:textAppearance="@style/TextAppearance.AppCompat.SearchResult.Subtitle"         tools:text="Loading" />  </LinearLayout> 

Manifest.xml:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.geeklabs.webviewkotlin">      <uses-permission android:name="android.permission.INTERNET" />     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />      <application         android:allowBackup="true"         android:fullBackupContent="false"         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> 

strings.xml:

<resources>     <string name="app_name">WebViewKotlin</string>     <string name="please_wait">Please wait&#8230;</string>     <string name="no_internet">No internet connection!</string>     <string name="settings">Settings</string>     <string name="back_again_to_exit">Please click BACK again to exit</string> </resources> 

build.gradle:

apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions'  android {     compileSdkVersion 30     buildToolsVersion "30.0.0"      defaultConfig {         applicationId "com.geeklabs.webviewkotlin"         minSdkVersion 23         targetSdkVersion 30         versionCode 1         versionName "1.0"          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"     }      buildTypes {         release {             minifyEnabled false             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'         }     } }  dependencies {     implementation fileTree(dir: "libs", include: ["*.jar"])     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"     implementation 'androidx.core:core-ktx:1.3.1'     implementation 'androidx.appcompat:appcompat:1.1.0'     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'     implementation 'com.google.android.material:material:1.1.0'     testImplementation 'junit:junit:4.13'     androidTestImplementation 'androidx.test.ext:junit:1.1.1'     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'  } 

Here is the complete working code in Git hub. Click here to navigate to Git Hub