Flutter:MainActivity cannot be converted to FlutterEngine in Java Native code

Question

I am trying to create a plugin for Flutter in Java. I am trying to pass the Android activity parameter in my main Java class.

This is my native code:

package com.example.trsurveys;

import androidx.annotation.NonNull;
import android.app.Activity;

import io.flutter.embedding.engine.plugins.FlutterPlugin;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;
import io.flutter.plugin.common.PluginRegistry.Registrar;

import theoremreach.com.theoremreach.TheoremReach;


public class TrsurveysPlugin implements FlutterPlugin, MethodCallHandler {
  private MethodChannel channel;
  private Registrar registrar;
  private Activity activity;

  @Override
  public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBinding) {
    channel = new MethodChannel(flutterPluginBinding.getFlutterEngine().getDartExecutor(), "trsurveys");
    channel.setMethodCallHandler(this);
  }

When I try to debug my app it shows me the following errors

    private TrsurveysPlugin(Activity activity) {
        this.activity = activity;
    }

  public static void registerWith(Registrar registrar) {
    final MethodChannel channel = new MethodChannel(registrar.messenger(), "trsurveys");
    channel.setMethodCallHandler(new TrsurveysPlugin(registrar.activity()));
  }

  @Override
  public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
    if (call.method.equals("init")) {
      String apiKey = call.argument("apiKey");
      TheoremReach.initWithApiKeyAndUserIdAndActivityContext(apiKey, "USER_ID", activity);
    }
  }

  @Override
  public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
    channel.setMethodCallHandler(null);
  }
}

When I try to debug my app I get the following errors:

error: constructor TrsurveysPlugin in class TrsurveysPlugin cannot be applied to given types;
    flutterEngine.getPlugins().add(new com.example.trsurveys.TrsurveysPlugin());
                                   ^
  required: Activity
  found: no arguments
  reason: actual and formal argument lists differ in length

...path/Downloads/TheoremReach-error/example/android/app/src/main/java/com/example/trsurveys_example/MainActivity.java:11: error: incompatible types: MainActivity cannot be converted to FlutterEngine
    GeneratedPluginRegistrant.registerWith(this);
                                       ^

This is the code that appears in my GeneratedPluginRegistrant.java file.

package io.flutter.plugins;

import androidx.annotation.Keep;
import androidx.annotation.NonNull;

import io.flutter.embedding.engine.FlutterEngine;

@Keep
public final class GeneratedPluginRegistrant {
  public static void registerWith(@NonNull FlutterEngine flutterEngine) {
    flutterEngine.getPlugins().add(new com.example.trsurveys.TrsurveysPlugin());
  }
}

While making the Plugin I have tried deleting the GeneratedPluginRegistrant.java file but every time it gets generated with the same configurations.

Answer 1

Open your project manifest file and remove this Lines

meta-data
android:name=”flutterEmbedding”
android:value=”2″

Then build and run it again.