Why can't using BarcodeScanner inside a service?

Ionic Framework ionic-v3
1

As title, I got a runtime error:

Can’t resolve all parameters for ScannerService: (?).

codes :

   import { BarcodeScanner } from '@ionic-native/barcode-scanner';

    export class ScannerService{
        
        constructor(
            private barcodeScanner: BarcodeScanner    
            ) {
            console.log('Hello ScannerService Provider');
        }
      ...
    }

If I remove private barcodescanner, it runs fine.
Anyone can help?

2

Did you also import the barcodeScanner in your app.module.ts? This error is telling you that the BarcdeScanner isn’t provided. So double check if you added the BarcodeScanner to your providers :slight_smile: in app.module

1 Like
3

Yes, already did that, and double checked, like below:

providers: [
StatusBar,
SplashScreen,
NativeStorage,
BarcodeScanner,
{provide: ErrorHandler, useClass: IonicErrorHandler}
]

Anything else need I check?

4

And is the BarcodeScanner working from any other parts or pages inside your app (so outside of the service)

5

BTW you didn’t define your service with @Injectable() prefix. Thats whats possibly is going wrong?

6

Oh YES, thank you~

I put this Injectable line in other 2 service but forgot this one …

7

haha okay glad it’s working now. Just use the CLI generator with ionic g provider myProvider/myService to create it automatically with an @Injectable() decorator.

8

OK, thank you~~
This cli is really handy~