Ticket T319354

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PDF Viewer Highlight text in different colors.

Haruun Mohamud

created 9 years ago

How to save or capture highlighted PDF text using PDF viewer. Basically is there way to do color coded Highlighted text. Please advise. Thanks

Comments (2)

DevExpress Support Team 9 years ago

Hello Haruun,

Would you please clarify the task you trying to accomplish? Do you want to highlight text in the PDFViewer control or save highlighted text in the PDF document?

Thanks.
Elliot

Haruun Mohamud 9 years ago

I would like to accomplish both. I can highlighted, but how do I change the color or supply different color for the highlighted text. Then I would like to save it. I can open window asking user to save it, but I am not sure if the highlighted text will stay highlighted. Thanks for the feedback.

Answers approved by DevExpress Support

DevExpress Support Team

created 9 years ago

Hello Haruun,

Thank you for your clarification. You can use the PdfDocumentProcessor.FindText method to find text in the PDF document. Then, call the PdfViewerControl.ConvertDocumentPositionToPixel method to get coordinates of a point corresponding to a document position and call the PdfGraphics.FillPolygon method to highlight text in the PDF Document.

Thanks,
Elliot

PS. Please note that the PDFDocumentProcessor control is located in two packages: Universal Subscription and .NET Document Automation. So, it is necessary to have a license for one of these subscriptions to be able to use PDFDocumentProcessor in the application.

Show previous comments (4)

Haruun Mohamud 9 years ago

Thanks for the feedback. I have been busy with other projects. Do you have an example code for doing the above? I want to highlight than save the document to new file. Please advise. Thanks!

Maria Nikulina (DevExpress) 9 years ago

Hello Haruun,
I've created a simple example illustrating how to find and highlight words. Please refer to the attached project.
In my sample, I search for only one word and draw a single rectangle. However, the search result may contain multiple words that can be rotated. So, it's necessary to take this point into account while implementing the approach in your source application. Please feel free to contact me if you have further questions.

dxT319354.zip

Haruun Mohamud 9 years ago

Hi this won't highlight a paragraph, but it will only highlight first set of characters. Please see attached document. This is really important to us. I need to highlight and save the highlighted text not search string. Can PdfDocumentProcess do that? Please advise. Thanks!

pdf1.png

Haruun Mohamud 9 years ago

I figure a workaround. I split the string into multiple lines and looped to add the highlight. Seems to work fine. But is there a better way. A way that document process can take a blob of strings and do it's magic. Please advise. Thanks!

Here is the update code. Also reattaching the sample with my solution incase this is the only way to accomplish this.

C#
  string content = @"Hans had served his master for seven years, so he said to him, ""Master, my time is up; now I should be glad  
to go back home to my mother; give me my wages."" The master answered, ""You have served me faithfully  
and honestly; as the service was so shall the reward be;";  

 string[] lines = content.Split(new string[] { "\r\n", "\n" }, StringSplitOptions.None);  

//FindWord("Hans", processor, new SolidBrush(Color.FromArgb(50, 0, 0, 255)));  
FindWord(lines, processor, new SolidBrush(Color.FromArgb(75, 255, 216, 1)));  

//then call function and loop  
static void FindWord(string[] lines, PdfDocumentProcessor processor, SolidBrush brush)  
        {  
           foreach(var l in lines)  
            {  

                PdfTextSearchResults result = processor.FindText(l);  

                while (result.Status == PdfTextSearchStatus.Found)  
                {  
                    using (PdfGraphics graph = processor.CreateGraphics())  
                    {  
                        DrawGraphics(graph, result, brush);  
                    }  
                    result = processor.FindText(l);  
                }  

            }  

            processor.SaveDocument("result.pdf");  
            Process.Start("result.pdf");  
        }

Attached is the modified sample.

highlighti...f text.zip

DevExpress Support Team 9 years ago

Hello,

The cause of this behavior is that multiline text is surrounded by several rectangles. Thus, the PdfTextSearchResults.Rectangles property contains more than one item. To overcome the issue, modify the code Mariya provided to calculate the correct location of the text. Modify the DrawGraphics method in Mariya's project for this purpose.

C#
  static void DrawGraphics(PdfGraphics graph, PdfTextSearchResults result, SolidBrush brush)  
        {  
..

Should you have any questions or concerns while implementing this approach, let me know.

Haruun Mohamud 9 years ago

Can provide example how to modify the drawing using your method. The way I did works, but I am interested to see how your method will work. Thanks for the quick feedback.

DevExpress Support Team 9 years ago

A possible implementation of the DrawGraphics method to highlight multiline text may look like this:

C#
static void DrawGraphics(PdfGraphics graph, PdfTextSearchResults result, SolidBrush brush)  
        {  
            for (int i = 0; i < result.Rectangles.Count; i++)  
            {  
                RectangleF rect = new RectangleF(new PointF((float)result.Rectangles[i].Left, (float)result.Page.CropBox.Top - (float)result.Rectangles[i].Top),  
                    new SizeF((float)result.Rectangles[i].Width, (float)result.Rectangles[i].Height));  
                graph.FillRectangle(brush, rect);  
            }  

            graph.AddToPageForeground(result.Page, 72, 72);  
        }

I have modified Mariya's previous project to demonstrate the approach in action. You can find the project in the attachment.

I hope you will find my sample useful.

T319354_modified.zip

Created: December 2, 2015 4:57 AM

Modified: June 10, 2016 8:17 PM

Platform: Office File API

Product: PDF Document API

Framework / Specific: .NET Framework

Build: 15.1.8

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PDF Viewer Highlight text in different colors.

Answers approved by DevExpress Support

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