public async Task ScanAsync() { _stopped = false; // Initialize the scanner first so it can track the current context ZXing.Mobile.MobileBarcodeScanner.Initialize(_androidApplication); var scanner = new ZXing.Mobile.MobileBarcodeScanner(); var opt = new ZXing.Mobile.MobileBarcodeScanningOptions() { // DelayBetweenContinuousScans = 1000, UseNativeScanning = true, }; scanner.ScanContinuously(opt, f); // return null; }