如何使用iTextSharp绘制轮廓颜色为红色，内部颜色为灰色的水印文本

Question

如何使用iTextSharp绘制轮廓颜色为红色，内部颜色为灰色的水印文本

Answer 1

如果您正在使用水印，我假设您正在谈论PdfStamper。如果是这样，一旦你用GetOverContent()或GetUnderContent()得到一个原始的PdfContentByte，你只需要设置几个属性。

• PdfContentByte.SetLineWidth(single) -设置描边厚度
• PdfContentByte.SetColorFill(BaseColor.GRAY) -设置填充颜色。您还可以使用任何其他颜色方法，如SetRGBColorFill()或SetCMYKColorFill()
• PdfContentByte.SetColorStroke(BaseColor.RED) -设置描边颜色
• PdfContentByte.SetTextRenderingMode(PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE) -标志，你想要绘制文本填充和描边

下面是一个完整的WinForms应用程序，目标是iTextSharp 5.1.1.0，把它放在一起。您应该能够将其移动到ASP。如果需要的话，还可以将其转换为c#。

Option Explicit On
Option Strict On
Imports iTextSharp.text
Imports iTextSharp.text.pdf
Imports System.IO
Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ''//Our sample files
        Dim InputFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Test.pdf")
        Dim OutputFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "Test_W_Watermark.pdf")
        ''//Create our input file to watermark later, nothing special here
        Using FS As New FileStream(InputFile, FileMode.Create, FileAccess.Write, FileShare.Read)
            Using Doc As New Document(PageSize.LETTER)
                Using W = PdfWriter.GetInstance(Doc, FS)
                    Doc.Open()
                    Doc.Add(New Paragraph("This is a test"))
                    Doc.Close()
                End Using
            End Using
        End Using

        ''//Watermark the file that we create above
        ''//Bind a reader to our input file
        Dim R As New PdfReader(InputFile)
        ''//Create our output file stream
        Using FS As New FileStream(OutputFile, FileMode.Create, FileAccess.Write, FileShare.Read)
            ''//Bind a stamper to our output file stream
            Using stamper As New PdfStamper(R, FS)
                ''//Grab the raw content byte to draw with
                Dim cb = stamper.GetOverContent(1)
                ''//Flag that we are starting text commands
                cb.BeginText()
                ''//Set the stroke width
                cb.SetLineWidth(2)
                ''//Set the fill (inner) color for the font
                cb.SetColorFill(BaseColor.GRAY)
                ''//Set the stroke (outer) color for the font
                cb.SetColorStroke(BaseColor.RED)
                ''//Flag that when drawing text the system should use both a fill and a stroke
                cb.SetTextRenderingMode(PdfContentByte.TEXT_RENDER_MODE_FILL_STROKE)
                ''//Set a font to draw with
                cb.SetFontAndSize(BaseFont.CreateFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.EMBEDDED), 50)
                ''//Tell the system to start drawing at the center of the first page
                cb.SetTextMatrix(R.GetPageSize(1).Width / 2, R.GetPageSize(1).Height / 2)
                ''//Draw the actual text
                cb.ShowText("Hello")
                ''//Flag that we are done drawing text
                cb.EndText()
            End Using
        End Using
        Me.Close()
    End Sub
End Class