CODEWITHSUNDEEP
androidandroid-studiokotlin
Aniskonig
Aniskonig

Reputation: 31

particularly case of " WebView must not be null "

i'm trying in this code to open a website by clicking in a button which open the second activity and a link.

my first activity Code :

package com.medanis.fneclis

import android.content.Intent
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

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

        button1.setOnClickListener{
            val intent = Intent(this, License::class.java)
// To pass any data to another activity
            intent.putExtra("targetURL", "www.firstlink.com")
// start your SecondActivity
            startActivity(intent)

        }
        button2.setOnClickListener{
            val intent = Intent(this, License::class.java)
// To pass any data to another activity
            intent.putExtra("targetURL", "www.secondlink.com")
// start your SecondActivity
            startActivity(intent)

        }
        button3.setOnClickListener{
            val intent = Intent(this, License::class.java)
// To pass any data to another activity
            intent.putExtra("targetURL", "www.thirdlink.com")
// start your SecondActivity
            startActivity(intent)

        }
    }
}

my Second activity Code :

package com.medanis.fneclis

import android.content.Intent
import android.os.Build
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.annotation.RequiresApi
import android.webkit.ClientCertRequest
import android.webkit.WebResourceRequest
import android.webkit.WebView
import android.webkit.WebViewClient
import kotlinx.android.synthetic.main.activity_license.*
import kotlinx.android.synthetic.main.activity_license.view.*
import java.net.URL

class License : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_license) // replace with you xml file name webview
        var  url : String = intent.getStringExtra("value")?:""
        webv.webViewClient = WebViewClient()
        startActivity(intent)
    }
}

LIcense LAYout :

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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/bg2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/fneclis_phone_bg_5"
    android:orientation="vertical"
    android:theme="@style/AppFullScreenTheme"
    tools:context=".License">

    <Button
        android:id="@+id/wvbtn"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_marginEnd="316dp"
        android:layout_marginLeft="18dp"
        android:layout_marginRight="316dp"
        android:layout_marginStart="18dp"
        app:layout_constraintBottom_toTopOf="@+id/webv"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <WebView
        android:id="@+id/webv"
        android:layout_width="0dp"
        android:layout_height="513dp"
        android:layout_marginTop="36dp"
        android:background="@drawable/ic_launcher_background"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintDimensionRatio="w,1:1"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/wvbtn">

    </WebView>

</android.support.constraint.ConstraintLayout>

MAINACTIVITY layout :

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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/bg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/fneclis_phone_bg_3"
    android:orientation="vertical"
    android:theme="@style/AppFullScreenTheme"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button1"
        android:layout_width="263dp"
        android:layout_height="116dp"
        android:layout_marginBottom="25dp"
        android:layout_marginTop="13dp"
        android:background="@drawable/fneclis_btn"
        android:text="Next Page"
        android:textSize="30sp"
        app:layout_constraintBottom_toTopOf="@+id/button3"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.504"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button2" />

    <Button
        android:id="@+id/button3"
        android:layout_width="263dp"
        android:layout_height="116dp"
        android:layout_marginBottom="76dp"
        android:layout_marginTop="400dp"
        android:background="@drawable/fneclis_btn"
        android:text="Next Page"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.504"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/button2"
        android:layout_width="263dp"
        android:layout_height="116dp"
        android:layout_marginBottom="346dp"
        android:layout_marginTop="130dp"
        android:background="@drawable/fneclis_btn"
        android:text="Next Page"
        android:textSize="30sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.504"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0" />

</android.support.constraint.ConstraintLayout>

error message:

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.medanis.fneclis/com.medanis.fneclis.License}: java.lang.IllegalStateException: webv must not be null

Upvotes: 2

Views: 2182

Answers (2)

Dracarys
Dracarys

Reputation: 714

Actually there's a lot wrong with your code, firstly the background, get rid of that.

This is how the your activity_license.xml must look:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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/bg2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:theme="@style/AppFullScreenTheme"
    tools:context=".License">

    <WebView
        android:id="@+id/webv"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

    </WebView>

</android.support.constraint.ConstraintLayout>

Secondly, change the code in your entire License Activity, your onCreate must look like so:

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_license)
        val url: String = intent.getStringExtra("targetURL") ?: ""
        val webView = findViewById<WebView>(R.id.webv)
        webView.loadUrl(url)
    }

And please put actual urls on your button click logic, like so:

    button1.setOnClickListener{
        val intent = Intent(this, License::class.java)
        intent.putExtra("targetURL", "https://www.google.com")
        startActivity(intent)

    }

Upvotes: 1

Dracarys
Dracarys

Reputation: 714

This exact piece of code works finr with no errors

    val webview: WebView? = findViewById<WebView>(R.id.webv)
    webview?.webViewClient = WebViewClient()

Upvotes: 0

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