ZXing BarcodeWriter to Image not displaying (Xamarin.Forms)

[davidtavarez]

Using BarcodeWriter from the ZXing.Net.Mobile Nuget package. The code compiles without error does not display the barcode.

public BarcodePage : Page
{
    var barcodeWriter = new BarcodeWriter {
        Format = BarcodeFormat.QR_CODE,
        Options = new ZXing.Common.EncodingOptions {
            Width = 300,
            Height = 50,
            Margin = 30
        }

    };

    byte[] barcode = barcodeWriter.Write ("ABC12345678");

    ImageSource imageSource = ImageSource.FromStream (() => {
        MemoryStream ms = new MemoryStream (barcode);
        ms.Position = 0;
        return ms;
    });

    Image imageBarcode = new Image { Aspect = Aspect.AspectFill };
    imageBarcode.Source = imageSource; 

    Content = imageBarcode;
}

[Redth]

Which platform are you running this code on? does it work on any of them?

[rayeckel]

I am having the same issue. Does not work in WinPhone either. I have a PCL project, with code exactly as posted by davidavarez.

Windows throws the following error:
"The component cannot be found. (Exception from HRESULT: 0x88982F50)"

...with the following stack trace:
at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
at MS.Internal.XcpImports.BitmapSource_SetSource(BitmapSource bitmapSource, CValue& byteStream)
at System.Windows.Media.Imaging.BitmapSource.SetSourceInternal(Stream streamSource)
at System.Windows.Media.Imaging.BitmapImage.SetSourceInternal(Stream streamSource)
at System.Windows.Media.Imaging.BitmapSource.SetSource(Stream streamSource)
at Xamarin.Forms.Platform.WinPhone.StreamImagesourceHandler.d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at Xamarin.Forms.Platform.WinPhone.ImageRenderer.d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.b__3(Object state)

Looks to me like something is wrong in the "writer.encode" function that is causing the byte array to be malformed.

Thanks.

EDIT:
I got this working by leveraging the platform-specific versions of ZXing.Mobile.BarcodeWriter.

(per this post: http://forums.xamarin.com/discussion/28161/barcode-rendering-with-zxing-net-in-my-xamarin-forms-app )

Thanks.

[davidtavarez]

Using Xamarin.Forms on iOS and Android.

El 10 nov 2015, a las 10:51 a.m., Jonathan Dick notifications@github.com escribió:

Which platform are you running this code on? does it work on any of them?

—
Reply to this email directly or view it on GitHub.

[pedrollanes]

I have the same problem, with android. The code not throws any exception but don't show the image. My code is:

var writer = new BarcodeWriter
            {
                Format = BarcodeFormat.CODE_39,
                Options = new EncodingOptions
                {
                    Height = 400,
                    Width = 400,
                    PureBarcode = true,
                    Margin = 0
                },
            };
var imageBytes = writer.Write("48497094");

_barCodeImage.SetImageBitmap(BitmapFactory.DecodeByteArray(imageBytes, 0, imageBytes.Length));

[prefectlyspelt]

I am also seeing this issue, apparently the only workaround is to implement a custom interface to get the stream in the right format?

Cf. https://forums.xamarin.com/discussion/28161/barcode-rendering-with-zxing-net-in-my-xamarin-forms-app

[Redth]

Have you tried the latest version? I specifically fixed this for the Forms implementation on Android :)

[rlingineni]

I don't think it works on iOS? I don't see an image

[VangeM]

I have a simple solution for those who have had issues displaying a barcode after upgrading ZXing libraries.
My problem was that the BarcodeWriter.Write() function now returns a Byte array instead of a UIImage. I tried many ways of converting the byte array to a stream or an UIImage and then to a stream, etc., but nothing worked. The byte array seemed to contain the reasonable data, but it could not be converted to an image through any means.
The solution: It appears that there is now more than one version of the Write() function. I had a “Using ZXing.Common;” which worked fine before. You need to remove this or explicitly target the Write function in the ZXing.Mobile library. The right Write() function will go back to returning a UIImage. Simple solution in the end….just wish it didn’t take me several hours to get there!

[stephenhauck]

I tried to use a Write from ZXing.Mobile but did not see one....

[IsmaelMendonca]

I am having the same problem, seems that the Write() function returns an invalid byte array, I coudn't convert it to an image. I suppose that is not possible to use it in a generic Xamarin Form PCL way, we gonna need to perform it individually for each plataform using dependency injection.

[nikolaynn1984]

Hello, I need to save the result generated using
<forms:ZXingBarcodeImageView VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand" BarcodeFormat="{Binding ValidatedSelectedFormat}" BarcodeValue="{Binding ValidatedCode}" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2" >
in jpeg format on the device. I searched for a lot of time on the Internet, I did not find the result. Can you help?
Thanks in advance,