'Flutter web view doesn't work on release mode

I'm creating a Flutter application.

If I run this application on debug mode webview works well

but if I run this application on release mode it shows blank screen. It's showing PlatformException

I tried to get help from github issues but couldn't find the solution.

Manifest

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

build.gradle

minSdkVersion 20
targetSdkVersion 29

pubspec.yaml

webview_flutter: ^1.0.7

Error Log

E/flutter (16872): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: PlatformException(error, java.lang.IllegalStateException: Trying to create a platform view of unregistered type: plugins.flutter.io/webview
E/flutter (16872):      at io.flutter.plugin.platform.j$a.g(Unknown Source:229)
E/flutter (16872):      at io.flutter.embedding.engine.i.j$a.b(Unknown Source:152)
E/flutter (16872):      at io.flutter.embedding.engine.i.j$a.j(Unknown Source:144)
E/flutter (16872):      at e.a.c.a.j$a.a(Unknown Source:17)
E/flutter (16872):      at io.flutter.embedding.engine.e.b.d(Unknown Source:57)
E/flutter (16872):      at io.flutter.embedding.engine.FlutterJNI.handlePlatformMessage(Unknown Source:4)
E/flutter (16872):      at android.os.MessageQueue.nativePollOnce(Native Method)
E/flutter (16872):      at android.os.MessageQueue.next(MessageQueue.java:335)
E/flutter (16872):      at android.os.Looper.loop(Looper.java:183)
E/flutter (16872):      at android.app.ActivityThread.main(ActivityThread.java:7660)
E/flutter (16872):      at java.lang.reflect.Method.invoke(Native Method)
E/flutter (16872):      at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
E/flutter (16872):      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
E/flutter (16872): , null, null)
E/flutter (16872): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:581)
E/flutter (16872): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:158)
E/flutter (16872): <asynchronous suspension>
E/flutter (16872): #2      TextureAndroidViewController._sendCreateMessage (package:flutter/src/services/platform_views.dart:1036)
E/flutter (16872): <asynchronous suspension>
E/flutter (16872): #3      AndroidViewController.create (package:flutter/src/services/platform_views.dart:742)
E/flutter (16872): <asynchronous suspension>
E/flutter (16872): #4      RenderAndroidView._sizePlatformView (package:flutter/src/rendering/platform_view.dart:195)
E/flutter (16872): <asynchronous suspension>

Solution 1:^[1]

Please check for "android.permission.INTERNET" pemission in your Manifest file. In "app/src/main/AndroidManifest.xml" folder. I use flutter_inappwebview: ^5.3.2 plugin and faced same issue in release mode.

Solution 2:^[2]

I believe I ran into this same issue and what was happening was that there was both a cached flutter engine that had been initialised as well as a new flutter engine created later.

From that I went with a cached flutter engine and used a method channel to navigate as required.

So at some point somewhere(probably in your MainActivity or iOS equivalent) setup your Cached Flutter Engine:

       val flutterEngine = FlutterEngine(this)

        flutterEngine.dartExecutor.executeDartEntrypoint(
                DartExecutor.DartEntrypoint.createDefault()
        )

        FlutterEngineCache
                .getInstance()
                .put(INSERT_YOUR_DESIRED_FLUTTER_ENGINE_ID_HERE, flutterEngine)

Then when you want to open your FlutterFragment(Android example):

       var flutterEngine = FlutterEngineCache
                .getInstance()
                .get(INSERT_YOUR_FLUTTER_ENGINE_ID_FROM_BEFORE_HERE)

       var flutterFragment = FlutterFragment
               .withCachedEngine(INSERT_YOUR_FLUTTER_ENGINE_ID_FROM_BEFORE_HERE)
               .build()

        MethodChannel(
                flutterEngine.dartExecutor.binaryMessenger,
                INSERT_YOUR_DESIRED_METHOD_CHANNEL_NAME_HERE
        ).invokeMethod("setRoute", INSERT_ROUTE_YOU_WANT_HERE)

        openFragment(flutterFragment!!)

And an example of how you might use this method channel in your Flutter Dart code

class _MyViewState extends State<MyView> {

  static const myMethodChannel = const MethodChannel(INSERT_YOUR_DESIRED_METHOD_CHANNEL_NAME_HERE);

  Future<void> _handleMethodCalls(MethodCall call) async {
    switch (call.method) {
      case "setRoute":
        Navigator.pushReplacmentNamed(context, INSERT_YOUR_DESIRED_ROUTE_NAME_HERE)
       ...
    }
  }

...

  @override
  void initState() {
    super.initState();
    platform.setMethodCallHandler(_handleMethodCalls);
  }

}

Solution 3:^[3]

I think you did not give internet permission in android/app/src/main/AndroidManifest.xml

add this line into the <manifest of android/app/src/main/AndroidManifest.xml

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

and more information for Flutter Insecure http is not allowed by platform you can see this discussion

<uses-permission android:name="android.permission.INTERNET" /> //This line add
<application
    android:name="io.demo.app.test"
    android:label="ProjectName"
    android:usesCleartextTraffic="true" //This line add
    android:icon="@mipmap/ic_launcher">

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Niyaz Ginatullin
Solution 2	CLL
Solution 3	Gunjon Roy

'Flutter web view doesn't work on release mode

Solution 1:[1]

Solution 2:[2]

Solution 3:[3]

Sources

Related Questions

Solution 1:^[1]

Solution 2:^[2]

Solution 3:^[3]