Sử dụng iTextSharp để vẽ hình trong file PDF trong Asp.net

By Unknown - Friday, September 4, 2015 - No Comments

(How to add Watermark in PDF file using iTextSharp in ASP.NET) – Để bảo vệ bản quyền tác giả đối với các tài liệu khi xuất bản, tác giả thường sử dụng chức năng Watermark. Khi chèn Watermark vào tài liệu, dòng chữ này sẽ hiển thị mờ ở nền mà không ảnh hưởng đến nội dung. Bài viết dưới đây,chúng tôi sẽ giới thiệu với các bạn cách sử dụng thư viện iTextSharp để chèn Watermark vào file PDF. Chương trình sẽ cho phép người sử dụng 1 trong 2 cách đó là sử dụng ký tự (Text) hoặc sử dụng hình ảnh (Image) để chèn Watermark.

Nghe những bài hát đỉnh nhất về Thấy cô giáo - Nghe trên Youtube

- B1: Tạo Project trong Microsoft Visual Studio 2010

- B2: Download thư viện iTextSharp tại đây

- B3: References itextsharp.dll trong thư mục vừa giải nén vào Project.

- B4: Mở file Default.aspx dưới dạng HTML và nhập mã HTML
C#

<%@ Page Title="Using iTextSharp to Drawing shapes and Graphics in ASP.NET" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="AddWatermarkToPDFUsingiTextSharp._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

<tr>

<td>

<asp:label id="lblHeader" runat="server" Text="Using iTextSharp to Drawing shapes and Graphics in ASP.NET"></asp:label>

</div>

</div>

<asp:LinkButton id="cmdDrawing" runat="server" CssClass="btn btn-small" OnClick="cmdDrawing_Click" ValidationGroup="Text" Causesvalidation="true">

</asp:LinkButton>

</div>

</td>

</tr>

</table>

</asp:Content>

VB.NET Code

<%@ Page Title="Using iTextSharp to Drawing shapes and Graphics in ASP.NET" Language="vb" MasterPageFile="~/Site.Master" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="DrawingshapesGraphicsUsingiTextSharp._Default" %>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">

<tr>

<td>

<asp:label id="lblHeader" runat="server" Text="Using iTextSharp to Drawing shapes and Graphics in ASP.NET"></asp:label>

</div>

</div>

<asp:LinkButton id="cmdDrawing" runat="server" CssClass="btn btn-small" ValidationGroup="Text" Causesvalidation="true">

</asp:LinkButton>

</div>

</td>

</tr>

</table>

</asp:Content>

- B5: Viết Code cho file Default.aspx

C# Code

//Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

using Microsoft.VisualBasic;

using System;

using System.Data;

using System.IO;

using System.Text;

using System.Web.UI;

using System.Web;

using iTextSharp.text.html;

using iTextSharp.text;

using iTextSharp.text.html.simpleparser;

using iTextSharp.text.pdf;

namespace AddWatermarkToPDFUsingiTextSharp

{

public partial class _Default : System.Web.UI.Page

{

#region "Drawing shapes and Graphics"

private void DrawingshapesGraphicsUsingiTextSharp(string FileName)

{

Document oDoc = new Document(PageSize.A4, 10f, 10f, 5f, 0f);

oDoc.SetPageSize(iTextSharp.text.PageSize.A4.Rotate());

System.IO.MemoryStream msReport = new System.IO.MemoryStream();

Paragraph pLegend = new Paragraph();

try

{

PdfWriter writer = PdfWriter.GetInstance(oDoc, msReport);

oDoc.AddAuthor("laptrinhdotnet.com");

oDoc.AddSubject("Add Watermark To PDF");

oDoc.Open();

PdfContentByte ContentUnder = writer.DirectContentUnder;

ContentUnder.SetCMYKColorStroke(255, 255, 0, 0);

//Drawing Rectangle

ContentUnder.Rectangle(100f, 430f, 150f, 50f);

ContentUnder.Stroke();

//Drawing Ellipse

ContentUnder.Ellipse(100f, 420f, 400f, 300f);

ContentUnder.Stroke();

//Drawing Circle

ContentUnder.SetCMYKColorFill(0, 255, 255, 0);

ContentUnder.Circle(500f, 480f, 50f);

ContentUnder.Fill();

//Drawing Triangle

ContentUnder.MoveTo(500f, 260f);

ContentUnder.LineTo(500f, 410f);

ContentUnder.LineTo(650f, 260f);

ContentUnder.ClosePathStroke();

//Drawing Square

ContentUnder.Rectangle(100f, 200f, 60, 60);

ContentUnder.Stroke();

//Drawing a line

ContentUnder.MoveTo(180f, 250f);

ContentUnder.LineTo(280f, 180f);

ContentUnder.Stroke();

string sText = "Using iTextSharp to Drawing shapes and Graphics";

Chunk beginning = new Chunk(sText, new Font(Font.HELVETICA, 16f));

Phrase p1 = new Phrase(beginning);

pLegend.IndentationLeft = 220;

pLegend.Add(p1);

oDoc.Add(pLegend);

}

catch

{

}

oDoc.Close();

Response.Clear();

Response.AddHeader("content-disposition", "attachment;filename=" + FileName + ".pdf");

Response.ContentType = "application/pdf";

Response.BinaryWrite(msReport.ToArray());

Response.End();

}

#endregion

#region "Event Handles"

protected void cmdDrawing_Click(object sender, System.EventArgs e)

{

DrawingshapesGraphicsUsingiTextSharp("Drawing");

}

#endregion

}

VB.NET Code

'Visit http://www.laptrinhdotnet.com for more ASP.NET Tutorials

Imports iTextSharp.text.html

Imports iTextSharp.text

Imports iTextSharp.text.html.simpleparser

Imports iTextSharp.text.pdf

Imports System.IO

Namespace DrawingshapesGraphicsUsingiTextSharp

Public Class _Default

Inherits System.Web.UI.Page

#Region "Drawing shapes and Graphics"

Private Sub DrawingshapesGraphicsUsingiTextSharp(ByVal FileName As String)

Dim oDoc As New Document(PageSize.A4.Rotate, 20, 20, 30, 20)

oDoc.SetPageSize(iTextSharp.text.PageSize.A4.Rotate())

Dim msReport As New System.IO.MemoryStream()

Dim pLegend As New Paragraph()

Try

Dim writer As PdfWriter = PdfWriter.GetInstance(oDoc, msReport)

oDoc.AddAuthor("laptrinhdotnet.com")

oDoc.AddSubject("Add Watermark To PDF")

oDoc.Open()

Dim ContentUnder As PdfContentByte = writer.DirectContentUnder

ContentUnder.SetCMYKColorStroke(255, 255, 0, 0)

'Drawing Rectangle

ContentUnder.Rectangle(100.0F, 430.0F, 150.0F, 50.0F)

ContentUnder.Stroke()

'Drawing Ellipse

ContentUnder.Ellipse(100.0F, 420.0F, 400.0F, 300.0F)

ContentUnder.Stroke()

'Drawing Circle

ContentUnder.SetCMYKColorFill(0, 255, 255, 0)

ContentUnder.Circle(500.0F, 480.0F, 50.0F)

ContentUnder.Fill()

'Drawing Triangle

ContentUnder.MoveTo(500.0F, 260.0F)

ContentUnder.LineTo(500.0F, 410.0F)

ContentUnder.LineTo(650.0F, 260.0F)

ContentUnder.ClosePathStroke()

'Drawing Square

ContentUnder.Rectangle(100.0F, 200.0F, 60, 60)

ContentUnder.Stroke()

'Drawing a line

ContentUnder.MoveTo(180.0F, 250.0F)

ContentUnder.LineTo(280.0F, 180.0F)

ContentUnder.Stroke()

Dim sText As String = "Using iTextSharp to Drawing shapes and Graphics" & vbCrLf

Dim beginning As New Chunk(sText, New Font(Font.HELVETICA, 16.0F))

Dim p1 As New Phrase(beginning)

pLegend.IndentationLeft = 220

pLegend.Add(p1)

oDoc.Add(pLegend)

Catch e As Exception

Console.Error.WriteLine(e.Message)

End Try

oDoc.Close()

Response.Clear()

Response.AddHeader("content-disposition", "attachment;filename=" & FileName & ".pdf")

Response.ContentType = "application/pdf"

Response.BinaryWrite(msReport.ToArray())

Response.End()

End Sub

#End Region

#Region "Event Handles"

Private Sub cmdDrawing_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdDrawing.Click

DrawingshapesGraphicsUsingiTextSharp("Drawing")

End Sub

#End Region

End Class

End Namespace

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