MissingPluginException（在通道 app.meedu/flutter_facebook_auth 上找不到方法登录的实现）：Flutter

Question

I am trying to use Facebook Authentication in Flutter. I followed all the steps in proper order as given - https://facebook.meedu.app/docs/4.xx/android
https://developers.facebook.com/docs/facebook-login/android/ But, when I fresh restart my app (as told in many other answers), I still get the error-

MissingPluginException(No implementation found for method login on channel app.meedu/flutter_facebook_auth)

I get this line in the console and no other exception of any type. That's why I can't figure out where the problem is.

manifest file-

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.social_media_login">
    <queries>
        <provider android:authorities="com.facebook.katana.provider.PlatformProvider" /> <!-- allows app to access Facebook app features -->
        <provider android:authorities="com.facebook.orca.provider.PlatformProvider" /> <!-- allows sharing to Messenger app -->
    </queries>
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:label="social_media_login"
        android:name="${applicationName}"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />
            <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/facebook_app_id"/>
            <meta-data android:name="com.facebook.sdk.ClientToken" android:value="@string/facebook_client_token"/>
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <activity android:name="com.facebook.FacebookActivity"
            android:configChanges=
                "keyboard|keyboardHidden|screenLayout|screenSize|orientation"
            android:label="@string/app_name" />
        <activity
            android:name="com.facebook.CustomTabActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.VIEW" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data android:scheme="@string/fb_login_protocol_scheme" />
            </intent-filter>
        </activity>




        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
    </application>
</manifest>

pubspec file-

name: social_media_login
description: Grip September 2022 Social Media Login in Apps

# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.17.6 <3.0.0"

# Dependencies specify other packages that your package needs in order to work.
# To automatically upgrade your package dependencies to the latest versions
# consider running `flutter pub upgrade --major-versions`. Alternatively,
# dependencies can be manually updated by changing the version numbers below to
# the latest version available on pub.dev. To see which dependencies have newer
# versions available, run `flutter pub outdated`.
dependencies:
  flutter:
    sdk: flutter


  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^1.0.2
  twitter_login: ^4.2.3
  font_awesome_flutter: ^10.1.0
  google_sign_in: ^5.4.1
  flutter_facebook_auth: ^4.4.1
  provider: ^6.0.3
  shared_preferences: ^2.0.15
  flutter_profile_picture: ^2.0.0
  cached_network_image: ^3.2.1
dev_dependencies:
  flutter_test:
    sdk: flutter

  # The "flutter_lints" package below contains a set of recommended lints to
  # encourage good coding practices. The lint set provided by the package is
  # activated in the `analysis_options.yaml` file located at the root of your
  # package. See that file for information about deactivating specific lint
  # rules and activating additional ones.
  flutter_lints: ^2.0.0

# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter packages.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  assets:
    - Images/LoginPage/Login Page.jpg
    - Images/HomePage/DefaultProfileImage.jpg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

My dart code-

Future<void> _facebookSignIn() async {
    try {
      final result =
          await FacebookAuth.i.login(permissions: ['public_profile', 'email']);
      if (result.status == LoginStatus.success) {
        final userData = await FacebookAuth.i.getUserData();
        print(userData);
      }
    } catch (error) {
      print(error);
    }

I followed the following articles and documentation- https://pub.dev/packages/flutter_facebook_auth
https://developers.facebook.com/docs/facebook-login/android/

Please help me resolve the issue!

Answer 1

I also get this issue sometimes in some plugins but when I uninstall and reinstall it the app.

It worked for me.

Answer 2

I ran into the same issue today.

As it is said on this screenShot, that "Misssing plugin error" is thrown when u dont complete the configuration.

You should've miss some steps.

In my case i just forgot adding

this to AndroidManifest

```<meta-data android:name="com.facebook.sdk.ClientToken" android:value="@string/facebook_client_token"/>``` 

And this one to string.xml file

<string name="facebook_client_token">123-THIS-IS-YOUR-CLIENT-TOKEN</string>

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