编辑PDF以添加页码| VB.net

Imports iTextSharp.text
Imports iTextSharp.text.pdf

Public Class PDFEditor
    Public Sub AddPageNumbers(inputFile As String, outputFile As String)
        ' 打开输入PDF文件
        Dim reader As New PdfReader(inputFile)
        ' 创建输出PDF文件
        Dim output As New PdfStamper(reader, New FileStream(outputFile, FileMode.Create))
        
        ' 获取总页数
        Dim totalPages As Integer = reader.NumberOfPages
        
        ' 遍历每个页面
        For i As Integer = 1 To totalPages
            ' 获取当前页面的内容
            Dim currentPage As PdfDictionary = reader.GetPageN(i)
            
            ' 创建一个字体对象
            Dim font As BaseFont = BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED)
            
            ' 创建一个图形状态对象
            Dim graphicsState As New PdfGState()
            graphicsState.FillOpacity = 1
            
            ' 在页面的左下角添加页码
            Dim x As Integer = 10
            Dim y As Integer = 10
            Dim text As New Phrase(i.ToString(), New Font(font, 12))
            ColumnText.ShowTextAligned(output.GetOverContent(i), Element.ALIGN_LEFT, text, x, y, 0)
        Next
        
        ' 关闭输出PDF文件
        output.Close()
        ' 关闭输入PDF文件
        reader.Close()
    End Sub
End Class

' 使用示例
Dim editor As New PDFEditor()
editor.AddPageNumbers("input.pdf", "output.pdf")