如何使用iTextSharp在C#中讀取PDF文檔：

using IronPdf;

class Program
{
    static void Main()
    {
        string pdfPath = "sample.pdf";

        // Load the PDF document
        var pdf = new PdfDocument(pdfPath);

        // Extract all text from the loaded PDF document
        string extractedText = pdf.ExtractAllText();

        // Output the extracted text to the console
        Console.WriteLine(extractedText);
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main()
		Dim pdfPath As String = "sample.pdf"

		' Load the PDF document
		Dim pdf = New PdfDocument(pdfPath)

		' Extract all text from the loaded PDF document
		Dim extractedText As String = pdf.ExtractAllText()

		' Output the extracted text to the console
		Console.WriteLine(extractedText)
	End Sub
End Class

var pdf = new PdfDocument("sample.pdf");

// Access text from the first page
string pageText = pdf.Pages[0].Text;

Console.WriteLine(pageText);

Dim pdf = New PdfDocument("sample.pdf")

' Access text from the first page
Dim pageText As String = pdf.Pages(0).Text

Console.WriteLine(pageText)

var pdf1 = new PdfDocument("file1.pdf");
var pdf2 = new PdfDocument("file2.pdf");

// Merge the PDFs into a single document
var combinedPdf = PdfDocument.Merge(pdf1, pdf2);

combinedPdf.SaveAs("combined_output.pdf");

Dim pdf1 = New PdfDocument("file1.pdf")
Dim pdf2 = New PdfDocument("file2.pdf")

' Merge the PDFs into a single document
Dim combinedPdf = PdfDocument.Merge(pdf1, pdf2)

combinedPdf.SaveAs("combined_output.pdf")

var pdf = new PdfDocument("sample.pdf");

// Convert the PDF to an HTML string
string htmlContent = pdf.ToHtmlString();

Dim pdf = New PdfDocument("sample.pdf")

' Convert the PDF to an HTML string
Dim htmlContent As String = pdf.ToHtmlString()

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;

class Program
{
    static void Main()
    {
        string pdfPath = "sample.pdf";
        string extractedText = ExtractTextFromPdf(pdfPath);
        Console.WriteLine(extractedText);
    }

    // Method to extract text from a PDF
    static string ExtractTextFromPdf(string pdfPath)
    {
        // Use PdfReader to load the PDF
        using (PdfReader reader = new PdfReader(pdfPath))
        // Open the PDF document for processing
        using (iText.Kernel.Pdf.PdfDocument pdfDoc = new iText.Kernel.Pdf.PdfDocument(reader))
        {
            string text = "";
            // Iterate through each page and extract text
            for (int i = 1; i <= pdfDoc.GetNumberOfPages(); i++)
            {
                text += PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(i)) + Environment.NewLine;
            }
            return text;
        }
    }
}

Imports iText.Kernel.Pdf
Imports iText.Kernel.Pdf.Canvas.Parser

Friend Class Program
	Shared Sub Main()
		Dim pdfPath As String = "sample.pdf"
		Dim extractedText As String = ExtractTextFromPdf(pdfPath)
		Console.WriteLine(extractedText)
	End Sub

	' Method to extract text from a PDF
	Private Shared Function ExtractTextFromPdf(ByVal pdfPath As String) As String
		' Use PdfReader to load the PDF
		Using reader As New PdfReader(pdfPath)
		' Open the PDF document for processing
		Using pdfDoc As New iText.Kernel.Pdf.PdfDocument(reader)
			Dim text As String = ""
			' Iterate through each page and extract text
			Dim i As Integer = 1
			Do While i <= pdfDoc.GetNumberOfPages()
				text &= PdfTextExtractor.GetTextFromPage(pdfDoc.GetPage(i)) & Environment.NewLine
				i += 1
			Loop
			Return text
		End Using
		End Using
	End Function
End Class