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Redact text in PDF using C# WebForms and Angular JS

I’m evaluating GroupDocs.Annotation, to redact text in PDF or add annotation/redaction function to an existing ASP.NET WebForms project.

While the “GroupDocs.Annotation for .NET Web.Forms Example” is presented as a WebForms application, the actual implementation is using MVC WebAPI with Angular front-end.

Is there GroupDocs.Annotation sample project with WebForm as the UI available?


Please note that GroupDocs.Annotation for .NET is a UI-Agnostic, back-end API that could be integrated in any .NET project. Are you evaluating our ASP.NET WebForms project?

Yes, I’m evaluating the ASP.NET WebForms project from the following GitHub repo(1):

There is a message on this repo saying it’s moved to the following repo(2):

repo(2) compilation result in errors, which I couldn’t figure out how to resolve and ended up using repo(1) to do my evaluation.

I’m able to get repo(1) to work with a temp license.

I need to integrate document annotation/redaction into an existing ASP.NET WebForms project’s work-flow, brining up a specific document to annotate (perhaps launch another browser with query-parameter to open a specific document), and continue with the work-flow.

I believe my requirement is fairly common, not specific to ASP.NET WebForms, and apply to other platforms and coding environment.


You have to use some JS framework at the client side for example Angular JS to draw annotations or generate SVG paths. As GroupDocs.Annotation for .NET is UI-Agnostic API.

PDF Text Redaction in C#

Have a look at this documentation article - Add text redaction annotation in PDF using C#. Page position has to be passed through the client side, then API will add the particular annotation and save the PDF at the specified path.

Extending Angular functions to Redact Text in PDF
In order to understand the back-end API functionalities, please have a look at this console project. However, we are already investigating how to extend the Angular UI functions in existing C# WebForms application. We’ll let you know how to make changes in the Angular UI.

Thank You for the quick response!

We fully understand that it’s possible to use vanilla JavaScript to mark X-Y coordinate relative to a PDF document or other graphic file display in the browser, and send these X-Y coordinate along with the document’s display parameters to the back end to process the actual annotation/redaction.

We see the “GroupDocs.Annotation for .NET WebForms” example is a full featured annotation app, got our interest, and hope that we can adopt GroupDocs.Annotation without having to create our own.

Hope you can provide more information soon.

Again, thanks for your prompt and informative response.


Yes, we are investigating this scenario.


Please visit this thread - guidance on extending the Angular UI.