在ASP.NET Web窗体中呈现条形码

Question

i am trying to show the barcode in asp.net page. already download the zen barcode render with sample code. i tried the sample it is working fine with me. once i try in my code barcode label is showing empty. i checked with sample code and mine i did not find any difference , only data transfer is the different. this is what i tried.

<barcode:BarcodeLabel ID="BarcodeLabel1" runat="server" BarcodeEncoding="Code39NC" LabelVerticalAlign="Bottom" Text="12345"></barcode:BarcodeLabel>

---

 if (!IsPostBack)
            {  
 List<string> symbologyDataSource = new List<string>(
                Enum.GetNames(typeof(BarcodeSymbology)));
                symbologyDataSource.Remove("Unknown");
                barcodeSymbology.DataSource = symbologyDataSource;
                barcodeSymbology.DataBind();
}

this is the function

BarcodeSymbology symbology = BarcodeSymbology.Unknown;

        if (barcodeSymbology.SelectedIndex != 0)
        {
            symbology = (BarcodeSymbology)1;
        }
        symbology = (BarcodeSymbology)1;
        string text = hidID.Value.ToString();

        string scaleText = "1";
        int scale;
        if (!int.TryParse(scaleText, out scale))
        {
            if (symbology == BarcodeSymbology.CodeQr)
            {
                scale = 3;
            }
            else
            {
                scale = 1;
            }
        }
        else if (scale < 1)
        {
            scale = 1;
        }

        if (!string.IsNullOrEmpty(text) && symbology != BarcodeSymbology.Unknown)
        {
            barcodeRender.BarcodeEncoding = symbology;
            barcodeRender.Scale = 1;
            barcodeRender.Text = text;
        }

symbology is set as Code39NC from the dropdown. scale is 1 and text is coming from other form the value is passing as well. still the bacodelable is showing only value not the barcode picture.

Answer 1

Here are two code samples using ZXing to create a (QR) barcode as both an image and as a base64 encoded string. Both of these options can be used with an <img /> tag to embed the barcode in the page.

This is not an ASP.NET control. It is a library that creates barcodes from text.

// First Text to QR Code as an image
public byte[] ToQRAsGif(string content)
{
    var barcodeWriter = new BarcodeWriter
    {
        Format = BarcodeFormat.QR_CODE,
        Options = new EncodingOptions
        {
            Height = this._h,
            Width = this._w,
            Margin = 2
        }
    };

    using (var bitmap = barcodeWriter.Write(content))
    using (var stream = new MemoryStream())
    {
        bitmap.Save(stream, ImageFormat.Gif);
        stream.Position = 0;
        return stream.GetBuffer();
    }
}

// From Text to QR Code as base64 string
public string ToQRAsBase64String(string content)
{     
    var barcodeWriter = new BarcodeWriter
    {
        Format = BarcodeFormat.QR_CODE,
        Options = new EncodingOptions
        {
            Height = _h,
            Width = _w,
            Margin = 2
        }
    };

    using (var bitmap = barcodeWriter.Write(content))
    using (var stream = new MemoryStream())
    {
        bitmap.Save(stream, ImageFormat.Gif);
        return String.Format("data:image/gif;base64,{0}", Convert.ToBase64String(stream.ToArray()));
    }
}

Hope this helps! Happy coding.

UPDATE: Here is the link to their product page on codeplex: https://zxingnet.codeplex.com/