Implement custom serialization with QR-Code signatures Leave feedback
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GroupDocs.Signature provides ability to embed into QR-code signature custom objects. This feature is implemented over object serialization to string and further encryption. There is ability to provide custom encryption. This procedure requires implementation of interface IDataEncryption with two methods to encrypt and decrypt data.
Here are the steps to embed into QR-code text with custom encryption with GroupDocs.Signature:
- Define custom data encryption class that implements IDataEncryption interface. By default GroupDocs.Signature has several encryption implementation you can use but allows user to customize it.
- Implement class with properties and specify if needed class attributes (like custom serialization attribute, custom encryption attribute), specify attributes for properties like FormatAttribute attribute to specify serialization name and display format, same as SkipSerializationAttribute to mark property of class as not serialize
- Create new instance of Signature class and pass source document path as a constructor parameter.
- Create one or several objects of QrCodeSignOptions object with Data value
- Instantiate the QrCodeSignOptions object according to your requirements and custom object to Data property.
- Call Sign method of Signature class instance and pass QrCodeSignOptions to it.
This example shows how to specify custom serialization class. This class could be implemented also as Attribute (optional) to specify as class attribute.
class CustomSerializationAttribute : Attribute, IDataSerializer
{
public T Deserialize<T>(string source) where T : class
{
return JsonConvert.DeserializeObject<T>(source);
}
public string Serialize(object data)
{
var serializerSettings = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore };
return JsonConvert.SerializeObject(data, serializerSettings);
}
}
This example shows how to define custom class with serialization and encryption properties and setup Format attributes for properties.
// setup CustomSerialization Attribute to setup customer serialization(see example above)
[CustomSerialization]
public class DocumentSignatureData
{
[Format("SignID")]
public string ID { get; set; }
[Format("SAuth")]
public string Author { get; set; }
[Format("SDate", "yyyy-MM-dd")]
public DateTime Signed { get; set; }
[Format("SDFact", "N2")]
public decimal DataFactor { get; set; }
[SkipSerialization]
public string Comments { get; set; }
}
This example shows how to add custom object into metadata signature to Image document.
using (Signature signature = new Signature("sample.pdf"))
{
// create data encryption
IDataEncryption encryption = new CustomXOREncryption();
// create custom object
DocumentSignatureData documentSignatureData = new DocumentSignatureData()
{
ID = Guid.NewGuid().ToString(),
Author = Environment.UserName,
Signed = DateTime.Now,
DataFactor = 11.22M
};
// setup QR-Code options
QrCodeSignOptions options = new QrCodeSignOptions()
{
// set custom object to serialize to QR Code
Data = documentSignatureData,
// QR-code type
EncodeType = QrCodeTypes.QR,
// specify serialization encryption
DataEncryption = encryption,
// locate and aligh signature
Height = 100,
Width = 100,
VerticalAlignment = VerticalAlignment.Bottom,
HorizontalAlignment = HorizontalAlignment.Right,
Margin = new Padding() { Right = 10, Bottom = 10 }
};
// sign document to file
signature.Sign("QRCodeCustomSerialization.pdf", options);
}
You may easily run the code above and see the feature in action in our GitHub examples:
- GroupDocs.Signature for .NET examples, plugins, and showcase
- GroupDocs.Signature for Java examples, plugins, and showcase
- Document Signature for .NET MVC UI Example
- Document Signature for .NET App WebForms UI Example
- Document Signature for Java App Dropwizard UI Example
- Document Signature for Java Spring UI Example
Along with the full-featured .NET library, we provide simple but powerful free online apps.
To generate QR codes and/or sign your files with QR codes for free, you can use the QR Code Generator online app.
To sign PDF, Word, Excel, PowerPoint, and other documents you can use the other online apps from the GroupDocs.Signature App Product Family.
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