BlogTech

The fileTransfert variable must be initialize in the platform.ready().then() method.

import { FileTransfer } from "@ionic-native/file-transfer";
import { Platform } from 'ionic-angular';

...

private fileTransfer: FileTransferObject;

...

constructor(public transfer: FileTransfer, public platform: Platform) {
    this.platform.ready().then(
     (ready)=>{
       this.fileTransfer= this.transfer.create();
     }
   );
}