我想在 pdf 文件中搜索一个单词并替换它。例如搜索“错误”并替换为“正确”。我已经设法使用 iText v5.5.9 （礼貌http://www.codeguru.com/columns/vb/manipulating-pdf-files-with-itextsharp-and-vb.net-2012.htm）做一个测试程序有点工作正常（被替换的文本似乎在顶部）。我想知道 v7 iText 是否会更好/更简单，是否有人做过/可以提供帮助。下面是 v5 测试代码，它使用 r/w 密码从数据库中读取 pdf，然后使用 r/w 密码将其写入：
' Based on http://www.codeguru.com/columns/vb/manipulating-pdf-files-with-itextsharp-and-vb.net-2012.htm
Imports System.IO 'Working With Files
Imports System.Text 'Working With Text
Imports System.Data.SqlClient
Imports iTextSharp.text 'Core PDF Text Functionalities
Imports iTextSharp.text.pdf 'PDF Content
Imports iTextSharp.text.pdf.parser 'Content Parser
Imports pdf_clr.LocTextExtraction 'Import LocationTextExtractionStrategy Capabilities
Public Class Class1
Public Shared Sub ReplacePDFText(ByVal strSource As String, ByVal strDest As String, ByVal iDocType As SByte, ByVal strSearch As String, ByVal strReplace As String, ByVal bCase As Boolean)
' strSource is an int
Dim i As Integer
Dim strSqlConnection As String = "context connection=true"
strSqlConnection = "Data Source=SERVER;Initial Catalog=DATABASE;Integrated Security=True"
Dim dbPDF As Byte() = Nothing 'For doc from database
Dim pcbContent As PdfContentByte = Nothing 'Read PDF Content
Dim psStamp As PdfStamper = Nothing 'PDF Stamper Object
Dim strPassword As String = strSource
Using connection As New SqlConnection(strSqlConnection)
connection.Open()
Dim command As New SqlCommand("SELECT pdf FROM docstore WHERE id=" & strSource, connection)
dbPDF = command.ExecuteScalar()
End Using
If IsNothing(dbPDF) <> True Then 'Check if dbPDF filled
'Dim pdfFileReader As New PdfReader(strSource, Encoding.ASCII.GetBytes(strPassword)) 'Read Our File
Dim pdfFileReader As New PdfReader(dbPDF, Encoding.ASCII.GetBytes(strPassword)) 'Read PDF
If strDest.ToString = "" Then
'strDest = System.IO.Path.GetTempPath() & System.IO.Path.GetRandomFileName()
strDest = "C:\tmp\" & System.IO.Path.GetRandomFileName() & ".pdf"
End If
Dim msPDF As New MemoryStream()
psStamp = New PdfStamper(pdfFileReader, msPDF) 'Memorystream as destination
psStamp.Writer.CloseStream = False
' set r/w password to
psStamp.SetEncryption(Nothing, Encoding.ASCII.GetBytes(strPassword), PdfWriter.ALLOW_PRINTING, PdfWriter.DO_NOT_ENCRYPT_METADATA)
For intCurrPage As Integer = 1 To pdfFileReader.NumberOfPages 'Loop Through All Pages
Dim lteStrategy As LocTextExtractionStrategy = New LocTextExtractionStrategy 'Read PDF File Content Blocks
pcbContent = psStamp.GetUnderContent(intCurrPage) 'Look At Current Block
'Determine Spacing of Block To See If It Matches Our Search String
lteStrategy.UndercontentCharacterSpacing = pcbContent.CharacterSpacing
lteStrategy.UndercontentHorizontalScaling = pcbContent.HorizontalScaling
'Trigger The Block Reading Process
Dim currentText As String = PdfTextExtractor.GetTextFromPage(pdfFileReader, intCurrPage, lteStrategy)
Dim scCase As StringComparison = IIf(bCase = 0, StringComparison.CurrentCultureIgnoreCase, StringComparison.CurrentCulture)
'Call
DoSearchReplace(lteStrategy, pcbContent, psStamp, strSearch, strReplace, scCase, "SearchReplaceLayer")
Next 'page
psStamp.Close() 'Close Stamp Destination Object
msPDF.Position = 0
dbPDF = msPDF.ToArray
msPDF.Close()
msPDF.Dispose()
' Write file as check during testing
File.WriteAllBytes(strDest, dbPDF)
If IsNumeric(strSource) And 1 = 1 Then
Using connection As New SqlConnection(strSqlConnection)
Dim cmd As New SqlCommand
cmd.CommandText = "sp_DOCSTORE_ADD_binary" ' updates or inserts into db
' stored procedure parameters as needed
cmd.Parameters.Add("@FILE", Data.SqlDbType.VarBinary) : cmd.Parameters("@FILE").Value = dbPDF
cmd.Parameters.Add("@retvalue", Data.SqlDbType.Int).Direction = Data.ParameterDirection.ReturnValue
cmd.CommandType = Data.CommandType.StoredProcedure
cmd.Connection = connection
connection.Open()
i = cmd.ExecuteNonQuery()
End Using
End If
End If
End Sub
Public Shared Sub DoSearchReplace(ByRef lteStrategy As LocTextExtractionStrategy, ByRef pcbContent As PdfContentByte, ByRef psStamp As PdfStamper, ByVal strSearch As String, ByVal strReplace As String, ByVal scCase As StringComparison, ByVal strLayer As String)
'Determine Match(es)
Dim lstMatches As List(Of iTextSharp.text.Rectangle) = lteStrategy.GetTextLocations(strSearch, scCase)
Dim pdLayer As New PdfLayer(strLayer, psStamp.Writer) 'New layer and enable Overwriting Capabilities
'Set Fill Colour Of Replacing Layer
pcbContent.SetColorFill(BaseColor.WHITE)
For Each rctRect As Rectangle In lstMatches 'Loop Through Each Match
pcbContent.Rectangle(rctRect.Left, rctRect.Bottom, rctRect.Width, rctRect.Height) 'Create New Rectangle For Replacing Layer
pcbContent.Fill() 'Fill With Colour Specified
pcbContent.BeginLayer(pdLayer) 'Create Layer
pcbContent.SetColorFill(BaseColor.DARK_GRAY) 'Fill Layer
pcbContent.Fill() 'Fill Underlying Content
Dim pgState As PdfGState 'Create GState Object
pgState = New PdfGState()
pcbContent.SetGState(pgState) 'Set Current State
pcbContent.SetColorFill(BaseColor.BLACK) 'Fill Letters
pcbContent.BeginText() 'Start Text Replace Procedure
pcbContent.SetTextMatrix(rctRect.Left, rctRect.Bottom) 'Get Text Location
'Set New Font And Size
pcbContent.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA_OBLIQUE, BaseFont.CP1252, BaseFont.NOT_EMBEDDED), 12)
pcbContent.ShowText(strReplace) 'Replacing Text
pcbContent.EndText() 'Stop Text Replace Procedure
pcbContent.EndLayer() 'Stop Layer replace Procedure
Next 'rectangle
End Sub
干杯。