Xamarin.iOS ZXing.Net.Mobile barcode scanner - ios

Question

I'm trying to add barcode scanner feature to my xamarin.ios app. I'm developing from visual studio and I've added the Zxing.Net.Mobile component from xamarin components store.
I've implemented it as shown in the samples:
ScanButton.TouchUpInside += async (sender, e) => {
//var options = new ZXing.Mobile.MobileBarcodeScanningOptions();
//options.AutoRotate = false;
//options.PossibleFormats = new List<ZXing.BarcodeFormat>() {
// ZXing.BarcodeFormat.EAN_8, ZXing.BarcodeFormat.EAN_13
//};
var scanner = new ZXing.Mobile.MobileBarcodeScanner(this);
//scanner.TopText = "Hold camera up to barcode to scan";
//scanner.BottomText = "Barcode will automatically scan";
//scanner.UseCustomOverlay = false;
scanner.FlashButtonText = "Flash";
scanner.CancelButtonText = "Cancel";
scanner.Torch(true);
scanner.AutoFocus();
var result = await scanner.Scan(true);
HandleScanResult(result);
};
void HandleScanResult(ZXing.Result result)
{
if (result != null && !string.IsNullOrEmpty(result.Text))
TextField.Text = result.Text;
}
The problem is that when I tap the scan button, the capture view is shown correctly but if I try to capture a barcode nothing happens and it seems the scanner doesn't recognize any barcode.
Someone has experienced this issue? How can I made it work?
Thanks in advance for your help!

Answer 1

I answered a similar question here. I couldn't get barcodes to scan because the default camera resolution was set too low. The specific implementation for this case would be:
ScanButton.TouchUpInside += async (sender, e) => {
var options = new ZXing.Mobile.MobileBarcodeScanningOptions {
CameraResolutionSelector = HandleCameraResolutionSelectorDelegate
};
var scanner = new ZXing.Mobile.MobileBarcodeScanner(this);
.
.
.
scanner.AutoFocus();
//call scan with options created above
var result = await scanner.Scan(options, true);
HandleScanResult(result);
};
And then the definition for HandleCameraResolutionSelectorDelegate:
CameraResolution HandleCameraResolutionSelectorDelegate(List<CameraResolution> availableResolutions)
{
//Don't know if this will ever be null or empty
if (availableResolutions == null || availableResolutions.Count < 1)
return new CameraResolution () { Width = 800, Height = 600 };
//Debugging revealed that the last element in the list
//expresses the highest resolution. This could probably be more thorough.
return availableResolutions [availableResolutions.Count - 1];
}