Search Text And Draw Rectangle

This tutorial explains how to use Aspose.PDF for .NET to search for specific text in a PDF document, draw a rectangle around the found text, and save the modified document. The provided C# source code demonstrates the process step by step.

Prerequisites

Before proceeding with the tutorial, make sure you have the following:

Basic knowledge of C# programming language.
Aspose.PDF for .NET library installed. You can obtain it from the Aspose website or use NuGet to install it in your project.

Step 1: Set up the project

Start by creating a new C# project in your preferred integrated development environment (IDE) and add a reference to the Aspose.PDF for .NET library.

Step 2: Import necessary namespaces

Add the following using directives at the beginning of your C# file to import the required namespaces:

using Aspose.Pdf;
using Aspose.Pdf.Text;
using Aspose.Pdf.Content;
using Aspose.Pdf.Facades;

Step 3: Set the path to the document directory

Set the path to your document directory using the dataDir variable:

string dataDir = "YOUR DOCUMENT DIRECTORY";

Replace "YOUR DOCUMENT DIRECTORY" with the actual path to your document directory.

Step 4: Load the PDF document

Load the PDF document using the Document class:

Document document = new Document(dataDir + "SearchAndGetTextFromAll.pdf");

Replace "SearchAndGetTextFromAll.pdf" with the actual name of your PDF file.

Step 5: Create a TextFragmentAbsorber

Create a TextFragmentAbsorber object to find all instances of the input search phrase:

TextFragmentAbsorber textAbsorber = new TextFragmentAbsorber(@"[\S]+");

Replace @"[\S]+" with your desired regular expression pattern.

Step 6: Enable regular expression search

Enable regular expression search by setting the TextSearchOptions property of the absorber:

TextSearchOptions textSearchOptions = new TextSearchOptions(true);
textAbsorber.TextSearchOptions = textSearchOptions;

Step 7: Search on all pages

Accept the absorber for all the pages of the document:

document.Pages.Accept(textAbsorber);

Step 8: Draw a rectangle around the found text

Create a PdfContentEditor object and loop through the retrieved text fragments, drawing a rectangle around each text segment:

var editor = new PdfContentEditor(document);
foreach (TextFragment textFragment in textAbsorber.TextFragments)
{
    foreach (TextSegment textSegment in textFragment.Segments)
    {
        DrawBox(editor, textFragment.Page.Number, textSegment, System.Drawing.Color.Red);
    }
}

Step 9: Save the modified document

Save the modified document:

dataDir = dataDir + "SearchTextAndDrawRectangle_out.pdf";
document.Save(dataDir);

Make sure to replace "SearchTextAndDrawRectangle_out.pdf" with the desired output file name.

Sample source code for Search Text And Draw Rectangle using Aspose.PDF for .NET

// The path to the documents directory.
string dataDir = "YOUR DOCUMENT DIRECTORY";
// Open document
Document document = new Document(dataDir + "SearchAndGetTextFromAll.pdf");
// Create TextAbsorber object to find all the phrases matching the regular expression
TextFragmentAbsorber textAbsorber = new TextFragmentAbsorber(@"[\S]+");
TextSearchOptions textSearchOptions = new TextSearchOptions(true);
textAbsorber.TextSearchOptions = textSearchOptions;
document.Pages.Accept(textAbsorber); 
var editor = new PdfContentEditor(document); 
foreach (TextFragment textFragment in textAbsorber.TextFragments)
{
	foreach (TextSegment textSegment in textFragment.Segments)
	{
			DrawBox(editor, textFragment.Page.Number, textSegment, System.Drawing.Color.Red);
	}
}
dataDir = dataDir + "SearchTextAndDrawRectangle_out.pdf";
document.Save(dataDir);
Console.WriteLine("\nRectangle drawn successfully on searched text.\nFile saved at " + dataDir);

Conclusion

Congratulations! You have successfully learned how to search for specific text in a PDF document, draw a rectangle around the found text, and save the modified document using Aspose.PDF for .NET. This tutorial provided a step-by-step guide, from setting up the project to performing the required actions. You can now incorporate this code into your own C# projects to manipulate text and draw rectangles in PDF files.

FAQ’s

Q: What is the purpose of the “Search Text And Draw Rectangle” tutorial?

A: The “Search Text And Draw Rectangle” tutorial aims to guide users through the process of using the Aspose.PDF library for .NET to search for specific text within a PDF document, draw rectangles around the found text segments, and save the modified document. The tutorial provides detailed instructions and C# code samples to illustrate each step of the process.

Q: How does this tutorial help in drawing rectangles around specific text in a PDF document?

A: This tutorial provides a comprehensive guide on how to locate and draw rectangles around specific text segments within a PDF document. It demonstrates the process of setting up a project, loading a PDF document, enabling regular expression search, drawing rectangles around found text segments, and saving the modified PDF.

Q: What prerequisites are required to follow this tutorial?

A: Before starting the tutorial, you should have a basic understanding of the C# programming language. Additionally, you need to have the Aspose.PDF for .NET library installed. You can obtain it from the Aspose website or install it in your project using NuGet.

Q: How do I set up my project to follow this tutorial?

A: Begin by creating a new C# project in your preferred integrated development environment (IDE). Then, add a reference to the Aspose.PDF for .NET library to your project. This will enable you to use the library’s functionality to manipulate PDF documents.

Q: Can I draw rectangles around specific text using this tutorial?

A: Yes, the tutorial focuses on drawing rectangles around specific text segments within a PDF document. It demonstrates how to locate the desired text using regular expressions, create rectangles around the identified text segments, and save the modified PDF.

Q: How can I specify the text I want to search for and draw rectangles around?

A: To specify the text you want to search for and draw rectangles around, create a TextFragmentAbsorber object and set its pattern using the Text parameter. Replace the default pattern @"[\S]+" in the tutorial’s code with your desired regular expression pattern.

Q: How do I enable regular expression search for text?

A: Regular expression search is enabled by creating a TextSearchOptions object and setting its value to true. Assign this object to the TextSearchOptions property of the TextFragmentAbsorber instance. This ensures that the regular expression pattern is used during text search.

Q: How do I draw rectangles around the found text?

A: After identifying the text segments using the TextFragmentAbsorber, the tutorial provides a loop to iterate through these segments. For each text segment, the tutorial demonstrates how to create a rectangle around it using the DrawBox method and specify the rectangle’s appearance.

Q: What are the steps to save the modified PDF with drawn rectangles?

A: After drawing rectangles around the desired text segments, use the Document class’s Save method to save the modified document. The tutorial’s sample code showcases how to save the edited PDF and display a success message.

Q: Can I customize the appearance of the drawn rectangles?

A: Yes, you can customize the appearance of the drawn rectangles. In the tutorial’s sample code, the DrawBox method is used to create rectangles. You can modify properties such as color, style, and thickness to customize the appearance of the drawn rectangles.

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