Zxing.net.mobile: Cancel button for Xamarin.Forms version is missing

[wegascee]

The Getting Started guide proposes a ZXingScannerPage. Now on iOS there is no back button and the default overlay doesn't provide a cancel button (only torch). The user isn't able to go back or to stop the scanner.

I didn't found any option for ZXingScannerPage. So should I use a DependencyService instead or how should I handle this case?

[gustaveracosta]

create a custom overlay?

[wegascee]

I also thought on that and I could add an abort button. But I only have a reference to ZXingScannerPage, which doesn't offer a Cancel() or StopScanning() method.

[wegascee]

Now I'm using a custom overlay with an abort button:

var customOverlay = new StackLayout {
    HorizontalOptions = LayoutOptions.FillAndExpand,
    VerticalOptions = LayoutOptions.FillAndExpand
};

var abort = new Button
{
    Text = "Abort",
};

abort.Clicked += Abort_Clicked;

customOverlay.Children.Add(abort);

this.scanPage = new ZXingScannerPage(customOverlay: customOverlay);

private void Abort_Clicked(object sender, EventArgs e)
{
    Device.BeginInvokeOnMainThread(async () =>
    {
        this.scanPage.IsScanning = false;
        await Navigation.PopModalAsync();
    });
}

To abort the operation I navigate back to dismiss the scanner page and abort the operation. Seems to work. Don't forget to do that on the UI thread.

[oltsupport-icp]

Helpfull ......! Thanks

[raf66]

Here's another approach that does not use overlays. I wrapped my modal in a NavigationPage, then added a Cancel button as a ToolbarItem.
`

        var scannerPage = new ZXingScannerPage()
        {
            Title = "Scan QR Code"
        };

        scannerPage.OnScanResult += (result) =>
        {
            scannerPage.IsScanning = false;
            Device.BeginInvokeOnMainThread(async () =>
            {
                await Navigation.PopModalAsync();
                await DisplayAlert("Scanned", result.Text, "OK");
            });
        };

        var toolbarItem = new ToolbarItem { Text = "Cancel" };
        toolbarItem.Clicked += (s, e) =>
        {
            scannerPage.IsScanning = false;
            Device.BeginInvokeOnMainThread(async () =>
            {
                await Navigation.PopModalAsync();
            });
        };

        var navPage = new NavigationPage(scannerPage);
        navPage.ToolbarItems.Add(toolbarItem);

        await Navigation.PushModalAsync(navPage);

`