CODEWITHSUNDEEP
androidwebviewkotlin
Prateekro
Prateekro

Reputation: 566

Kotlin - Define variable globally for WebView

I'm trying to define a variable globally which is of the class WebView. In Android Java it could be easy done by writing the it

Java for global variable

 < ClassName > < variableName >

But in Kotlin I'm facing issue with its declaration.

class MainActivity : AppCompatActivity() {

var mywebview : WebView //<- This shows Property must be initialized or be abstract



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

override fun onStart() {
    super.onStart()

    mywebview = findViewById(R.id.webViewGyrix) as WebView

    mywebview.setWebViewClient(object : WebViewClient() {
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            view?.loadUrl(url);
            return true
        }
    } )
    mywebview.loadUrl("http://www.example.com/")
}

Upvotes: 16

Views: 22952

Answers (4)

Marcin Orlowski
Marcin Orlowski

Reputation: 75645

This shows Property must be initialized or be abstract

Then initialize it i.e. to null. This is not a final value and you will be able to change it later:

var mywebview : WebView? = null

Alternatively, you can use lateinit feature of Kotlin, which would let you prevent having nullable mywebview if not needed:

lateinit var webView: WebView

Upvotes: 22

Android01
Android01

Reputation: 24

Below code worked for me:

val mywebviewURL = "https://www.google.com"

  override fun onStart() {
    super.onStart()

    events_webview.setWebViewClient(object : WebViewClient() {
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            view?.loadUrl(url);
            return true
        }
    })
    events_webview.loadUrl(mywebviewURL)
}

Add internet permission to AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"/>

Upvotes: 0

Big Zak
Big Zak

Reputation: 1100

for a global variable, this means it shouldn't be overridden accidentally , so you should instead lazyload it using kotlin's lazy which create the variable on the first call, other calls will just reference the lazy loaded variable

private val webview:WebView by lazy{
  findViewById<WebView>(R.id.webview)
}

That should come before the onCreate method

Upvotes: 0

Bruno Wieczorek
Bruno Wieczorek

Reputation: 664

You can use late initialization - you don't have to make WebView nullable

lateinit var webView: WebView

Upvotes: 30

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