Disable text selection when rendering PDF to HTML

When rendering PDF documents to HTML with GroupDocs.Viewer you can disable text selection by rendering text as an image. When rendering text as an image the output HTML will look close to the source PDF document. To disable text selection set ViewOptions.PdfOptions.RenderTextAsImage = true.

Example

To let’s take one-page-text.pdf, convert it to HTML with default options and check output HTML document source. To convert PDF to HTML we’ll be running the following code:

using (Viewer viewer = new Viewer("one-page-text.pdf"))
{
    HtmlViewOptions viewOptions = 
        HtmlViewOptions.ForEmbeddedResources("default-options.html");

    viewer.View(viewOptions);
}

As a result, Viewer will produce a single HTML document default-options.html. If we open this document in a browser we’ll be able to select the text as is shown on the screenshot below:

Output HTML document and it’s source when rendering with default options

As you can see we can select the text because it is actually a text inside span element.

Let’s now run the following code and check the output, the differences here are the new line viewOptions.PdfOptions.RenderTextAsImage = true and output file name text-as-images.html:

using (Viewer viewer = new Viewer("one-page-text.pdf"))
{
    HtmlViewOptions viewOptions = 
        HtmlViewOptions.ForEmbeddedResources("text-as-images.html");
    viewOptions.PdfOptions.RenderTextAsImage = true;

    viewer.View(viewOptions);
}

We’ll get text-as-images.html on the output that will look similar to the previous result, but as you can see the text is replaced with an image that makes it impossible to select the text and copy it.

Output HTML document and it’s source when rendering with RenderTextAsImage set to true

More resources

View PDF Documents Online

Along with full-featured .NET library we provide simple but powerful free online Apps. View PDF files online with GroupDocs Viewer App.

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

Rendering pages to the same size as the size of pages in a source document View E-Mail Messages