How to set canOverrideExistingModule=true in React Native for Android Apps?

问题

I built an android app using React Native, it got built successfully but when I run the app in my Android Virtual Device it shows up a full red screen with the following error:

I have not done native app development ever before neither do I have any knowledge of Java so I have no idea what this error means and how to fix this.

回答1:

The name of the package associated to this error is not AirMapModule but MapsPackage from com.airbnb.android.react.maps.

In your MainApplication.java in directory : android/app/src/main/java/../../ remove any duplicate entry of :

the import package : import com.airbnb.android.react.maps.MapsPackage
the call to the constructor of the module : new MapsPackage() in function getPackages

回答2:

Go to file "MainApplication.java" (under .\android\app\src\main\java\com\projectName)

Make sure that under getPackages() function you don't have duplicate lines (in my case I had "new MapsPackage()" twice).

Fix duplicate imports as well.

Good luck

回答3:

Go to the MainAplication file.

Remove duplicate package and remove duplicate package in getPackages() method

  @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
          new MainReactPackage(),
            new VectorIconsPackage()
      );
    }

Then after try this command in your terminal :

cd android
./gradlew clean

回答4:

  @Override    
  public boolean canOverrideExistingModule() {        
    return true;    
  }

Add these code to your native module constructor would be fine

回答5:

If the version of RN you're using is >= 0.60 then there is the possibility that auto-linking and your manual linking are doing the same thing twice. You have two options:

1- You can revert code changes in getPackages method
2- You can disable auto linking in react-native-config.js file.

回答6:

You can try check in file MainApplication.java in directory : android\app\src\main\java is have any duplicate package AirMapModule exist or not, and delete 1 if have.