XZing and Xamarin Forms

Question

I'm trying to use ZXing to render a simple barcode on screen in Xamarin. I've added the ZXing package to my solution and have the following code:

        BarcodeWriterPixelData writer = new BarcodeWriterPixelData
        {
            Format = BarcodeFormat.CODE_39 ,
            Options = new ZXing.Common.EncodingOptions{
                Height = 80,
                Width = 30,
                Margin = 0
            }
        };
        var data = writer.Write("18898798790");
        IDBarCode.Source = ImageSource.FromStream(() => new MemoryStream(data.Pixels));

However my code runs without rendering anything on screen. I've been looking for some sort of sample I can use without any sucess.

Have you downloaded and ran the sample on their github? try that first! — Axemasta, Aug 08 '18 at 20:39

score 1 · Answer 1 · answered Aug 08 '18 at 17:47

1

Don't forget to initialize the ZXing library in your platform projects, else it will show up empty. You can do this by adding:

// On iOS in your AppDelegate.cs in the FinishedLaunching method
ZXing.Net.Mobile.Forms.iOS.Platform.Init();

and

// On Android in the MainActivity.cs in the OnCreate method
ZXing.Net.Mobile.Forms.Android.Platform.Init();

answered Aug 08 '18 at 17:47

Gerald Versluis

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Hi,Yes I do have that code but still nothing is shown on the page! – Amir Peivandi Aug 09 '18 at 03:07
What does your layout look like? Where is IDBarCode placed? – Gerald Versluis Aug 09 '18 at 06:07
My layout is the simplest of all! just a Image on page and I can display any image I want from a Uri or local file and the issue is when I try to render a barcode. I've debugged the code and changing the barcode actually changes the data I get from the function. I'm not sure if the data is valid but it's changing. – Amir Peivandi Aug 09 '18 at 10:46
– Amir Peivandi Aug 09 '18 at 10:51
it shows the cart image I asked and when I click on the button the image is replaced with nothing! – Amir Peivandi Aug 09 '18 at 10:51

score 0 · Answer 2 · answered Aug 09 '18 at 20:47

After trying tons of different things and getting nowhere and contacting the ZXing's dev team I gave up and used a different method.

I used a ZXing component instead if using a normal Image and all works fine now. Here is the code:

    private ZXingBarcodeImageView barcode=null;
    public MainPage()
    {
        InitializeComponent();
    }

    void Handle_Clicked(object sender, System.EventArgs e)
    {
        if (barcode==null){
            barcode = new ZXingBarcodeImageView
            {
                HorizontalOptions = LayoutOptions.FillAndExpand,
                VerticalOptions = LayoutOptions.FillAndExpand,
            };
            barcode.BarcodeFormat = ZXing.BarcodeFormat.CODE_128;
            barcode.BarcodeOptions.Width = 500;
            barcode.BarcodeOptions.Height = 100;
            barcode.BarcodeValue = contentEntry.Text.Trim();
            barResult.Content = barcode;
        }else{
            barcode.BarcodeValue = contentEntry.Text.Trim();
        }

    }

barResult is just a simple ContentView with nothing in it.

        <ContentView x:Name="barResult">                
        </ContentView>

XZing and Xamarin Forms

2 Answers2