ZXing.Mobile - How to change the size of the camera scanner? - xamarin

Question

UPDATE:
I've tried implementing this in an App.cs method called OpenCameraScanner (you would call this on click of a button on the page from which you want to scan):
App.cs
------------------------------------------------
public static ZXingScannerPage ScanPage;
public static ZXing.Result ScanResult;
public static async void OpenCameraScanner()
{
ScanPage = new ZXingScannerPage(customOverlay: customOverlay);
ScanPage.OnScanResult += (result) =>
{
ScanPage.IsScanning = false;
ScanResult = result;
Device.BeginInvokeOnMainThread(() =>
{
App.CurrentApp.CurrentPage.Navigation.PopModalAsync();
App.CurrentApp.CurrentPage.DisplayAlert("Scanned Barcode", result.Text, "OK");
});
};
var scanPage = new NavigationPage(ScanPage);
await App.CurrentApp.CurrentPage.Navigation.PushModalAsync(ScanPage);
}
However, when this method is called, the screen that opens is blank white, and you can't see the camera view behind it. Not sure why?
I'm using ZXing.Mobile in a Xamarin.Forms project (for iOS right now) for camera scanning functionality on an iPad.
Currently, I have it working great with the following 2 lines:
var scanner = new ZXing.Mobile.MobileBarcodeScanner();
var result = await scanner.Scan();
However, when the camera is open to scan, it takes up the entire iPad screen, which is really big.
Question: Is there a way to adjust the size of the camera overlay? (so that it's not full screen)
I see that the scanner.Scan() method takes an optional options parameter of type ZXing.Mobile.MobileBarcodeScanningOptions - I tried playing around with that, but the only possible relevant option there is a CameraResolutionSelector - but I'm having a really hard time finding any documentation on that.

Answer 1

There is a ZXing sample app that shows how to embed the ZXingScannerView and ZXingDefaultOverlay into a Xamarin.Form's Grid:
https://github.com/Redth/ZXing.Net.Mobile/blob/master/Samples/Forms/Core/CustomScanPage.cs
public CustomScanPage () : base ()
{
zxing = new ZXingScannerView
{
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand,
AutomationId = "zxingScannerView",
};
zxing.OnScanResult += (result) =>
Device.BeginInvokeOnMainThread (async () => {
// Stop analysis until we navigate away so we don't keep reading barcodes
zxing.IsAnalyzing = false;
// Show an alert
await DisplayAlert ("Scanned Barcode", result.Text, "OK");
// Navigate away
await Navigation.PopAsync ();
});
overlay = new ZXingDefaultOverlay
{
TopText = "Hold your phone up to the barcode",
BottomText = "Scanning will happen automatically",
ShowFlashButton = zxing.HasTorch,
AutomationId = "zxingDefaultOverlay",
};
overlay.FlashButtonClicked += (sender, e) => {
zxing.IsTorchOn = !zxing.IsTorchOn;
};
var grid = new Grid
{
VerticalOptions = LayoutOptions.FillAndExpand,
HorizontalOptions = LayoutOptions.FillAndExpand,
};
grid.Children.Add(zxing);
grid.Children.Add(overlay);
// The root page of your application
Content = grid;
}