Adding a PDF file using iText7

Question

Can I improve this code and make it more beautiful? For example, I am using a switch statement and for each page but I only add edits to page 1 and page 2?

byte[] b = null;
MemoryStream stream = new MemoryStream(buffer);
string _Number = "4.2021";
string _disclaimer = "Text";

using (MemoryStream returnMemoryStream = new MemoryStream())
     {
        PdfReader = new PdfReader(stream);
        PdfDocument pdfDocument = new PdfDocument(PdfReader, new PdfWriter(returnMemoryStream));
        int numberOfPages = pdfDocument.GetNumberOfPages();

        for (int i = 1; i <= 2; i++)
                {
                    PdfPage pdfPage = pdfDocument.GetPage(i);
                    PdfCanvas canvasPage = new PdfCanvas(pdfPage);
                    switch (i)
                    {
                        case 1:
                            int versionpage1X = 735;
                            int versionpage1Y = 248;
                            canvasPage.BeginText()
                                  .SetFontAndSize(PdfFontFactory
                                       .CreateFont(StandardFonts.HELVETICA_BOLD), 34)
                                  .MoveText(versionpage1X, versionpage1Y)
                                  .SetFillColor(ColorConstants.WHITE)
                                  .ShowText(_versionNumber)
                                  .EndText();

                            break;

                        case 2:

                            int versionpage2X = 760;
                            int versionpage2Y = 573;

                            canvasPage.BeginText()                                 
                           .SetFontAndSize(PdfFontFactory.CreateFont(StandardFonts.HELVETICA_BOLD), 21)
                                  .MoveText(versionpage2X, versionpage2Y)
                                  .SetFillColor(ColorConstants.WHITE)
                                  .ShowText(_versionNumber)
                                  .EndText();


                            float disclaimerpage2X = 75;
                            float disclaimerpage2Y = 26;


                            iText.Kernel.Geom.Rectangle rectangle = new iText.Kernel.Geom.Rectangle(disclaimerpage2X, disclaimerpage2Y, 883, 81);
                            Canvas canvas = new Canvas(canvasPage, rectangle);

                            Paragraph p = new Paragraph()
                              .Add(_disclaimer)
                              .SetFont(PdfFontFactory.CreateFont(StandardFonts.HELVETICA))
                              .SetFontColor(ColorConstants.BLACK)
                              .SetFontSize(12)
                              .SetTextAlignment(TextAlignment.LEFT);

                            canvas.Add(p);
                            canvas.Close();


                            //Image
                            float mapimageX = 111.318f;
                            float mapimageY = 130.791f;
                            float mapimageWidth = 755.454f;
                            float mapimageHeight = 432.094f;
                            ImageData imageData = ImageDataFactory.Create(@"PathtoImage.png");
                            iText.Kernel.Geom.Rectangle imagerectangle = new iText.Kernel.Geom.Rectangle(mapimageX, mapimageY, mapimageWidth, mapimageHeight);



                            canvasPage.AddImageFittedIntoRectangle(imageData, imagerectangle,true);


                            break;

                    }

                }
                pdfDocument.Close();
                b = returnMemoryStream.ToArray();
            }

Peter Csala · Accepted Answer · 2022-04-01 14:14:38Z

Main

I would suggest to extract the two case branches' code into separate methods. After that your top-level functionality could be simplified like this:

using var originalPdfStream = new MemoryStream(buffer);
using var modifiedPdfStream = new MemoryStream();

var pdfReader = new PdfReader(originalPdfStream);
var pdfDocument = new PdfDocument(pdfReader, new PdfWriter(modifiedPdfStream));

EditFirstPage(pdfDocument);
EditSecondPage(pdfDocument);

pdfDocument.Close();
byte[] modifiedPdfInBytes = modifiedPdfStream.ToArray();

I've renamed your variables to better express the intent (like stream >> originalPdfStream)
I've used C# 8's using declaration to reduce code indentation
- If you are using older C# version then you can only use here using statement

First page

void EditFirstPage(PdfDocument pdfDocument)
{
    var canvasPage = new PdfCanvas(pdfDocument.GetFirstPage());
    canvasPage.BeginText()
            .SetFontAndSize(PdfFontFactory.CreateFont(Common.Font), Page1.FontSize)
            .MoveText(Page1.Version.X, Page1.Version.Y)
            .SetFillColor(Common.FillColor)
            .ShowText(Common.VersionNumber)
            .EndText();
}

I've moved all the hard-coded values into a dedicated class called Page1
- Those constants that are shared between page 1 and 2 have been moved to a class called Common

static class Common
{
    public const string Font = StandardFonts.HELVETICA_BOLD;
    public static readonly Color FillColor = ColorConstants.WHITE;
    public const string VersionNumber = "4.2021";
}

static class Page1
{
    public const int FontSize = 34;
    public static class Version
    {
        public const int X = 735, Y = 248;
    }
}

Second Page

void EditSecondPage(PdfDocument pdfDocument)
{
    var canvasPage = new PdfCanvas(pdfDocument.GetPage(2));
    canvasPage.BeginText()
        .SetFontAndSize(PdfFontFactory.CreateFont(Common.Font), Page2.FontSize)
        .MoveText(Page2.Version.X, Page2.Version.Y)
        .SetFillColor(Common.FillColor)
        .ShowText(Common.VersionNumber)
        .EndText();

    var rectangle = new Rectangle(Page2.Disclaimer.X, Page2.Disclaimer.Y, Page2.Disclaimer.Width, Page2.Disclaimer.Height);
    var canvas = new Canvas(canvasPage, rectangle);

    var paragraph = new Paragraph()
        .Add(Page2.Paragraph.Disclaimer)
        .SetFont(PdfFontFactory.CreateFont(Page2.Paragraph.Font))
        .SetFontColor(Page2.Paragraph.FontColor)
        .SetFontSize(Page2.Paragraph.FontSize)
        .SetTextAlignment(TextAlignment.LEFT);

    canvas.Add(paragraph);
    canvas.Close();
    
    ImageData imageData = ImageDataFactory.Create(Page2.MapImage.FileName);
    var imageRectangle = new Rectangle(Page2.MapImage.X, Page2.MapImage.Y, Page2.MapImage.Width, Page2.MapImage.Height);

    canvasPage.AddImageFittedIntoRectangle(imageData, imageRectangle, true);
}

I've renamed some variables and moved the hard-coded values into a dedicated class

static class Page2
{
    public const int FontSize = 21;
    public static class Version
    {
        public const int X = 760, Y = 573;
    }
    public static class Disclaimer
    {
        public const float X = 75, Y = 26;
        public const float Width = 883, Height = 81;
    }
    public static class MapImage
    {
        public const string FileName = "PathtoImage.png";
        public const float X = 111.318f, Y = 130.791f;
        public const float Width = 755.454f, Height = 432.094f;
    }
    public static class Paragraph
    {
        public const string Disclaimer = "Text";
        public const string Font = StandardFonts.HELVETICA;
        public static readonly Color FontColor = ColorConstants.BLACK;
        public const int FontSize = 12;
    }
}

The code which adds the version number to a specific page is redundant. You can define a helper method to that like this:

void AddVersionNumber(PdfCanvas canvasPage, int fontSize, double x, double y)
    => canvasPage.BeginText()
        .SetFontAndSize(PdfFontFactory.CreateFont(Common.Font), fontSize)
        .MoveText(x, y)
        .SetFillColor(Common.FillColor)
        .ShowText(Common.VersionNumber)
        .EndText();

For the sake of completeness here is the full code

using var originalPdfStream = new MemoryStream(buffer);
using var modifiedPdfStream = new MemoryStream();

var pdfReader = new PdfReader(originalPdfStream);
var pdfDocument = new PdfDocument(pdfReader, new PdfWriter(modifiedPdfStream));

EditFirstPage(pdfDocument);
EditSecondPage(pdfDocument);

pdfDocument.Close();
byte[] modifiedPdfInBytes = modifiedPdfStream.ToArray();

void AddVersionNumber(PdfCanvas canvasPage, int fontSize, double x, double y)
    => canvasPage.BeginText()
        .SetFontAndSize(PdfFontFactory.CreateFont(Common.Font), fontSize)
        .MoveText(x, y)
        .SetFillColor(Common.FillColor)
        .ShowText(Common.VersionNumber)
        .EndText();

void EditFirstPage(PdfDocument pdfDocument)
    => AddVersionNumber(new PdfCanvas(pdfDocument.GetFirstPage()), Page1.FontSize, Page1.Version.X, Page1.Version.Y);

void EditSecondPage(PdfDocument pdfDocument)
{
    var canvasPage = new PdfCanvas(pdfDocument.GetPage(2));
    AddVersionNumber(canvasPage, Page2.FontSize, Page2.Version.X, Page2.Version.Y);

    var rectangle = new Rectangle(Page2.Disclaimer.X, Page2.Disclaimer.Y, Page2.Disclaimer.Width, Page2.Disclaimer.Height);
    var canvas = new Canvas(canvasPage, rectangle);
    var paragraph = new Paragraph()
        .Add(Page2.Paragraph.Disclaimer)
        .SetFont(PdfFontFactory.CreateFont(Page2.Paragraph.Font))
        .SetFontColor(Page2.Paragraph.FontColor)
        .SetFontSize(Page2.Paragraph.FontSize)
        .SetTextAlignment(TextAlignment.LEFT);

    canvas.Add(paragraph);
    canvas.Close();
    
    ImageData imageData = ImageDataFactory.Create(Page2.MapImage.FileName);
    var imageRectangle = new Rectangle(Page2.MapImage.X, Page2.MapImage.Y, Page2.MapImage.Width, Page2.MapImage.Height);

    canvasPage.AddImageFittedIntoRectangle(imageData, imageRectangle, true);
}

static class Common
{
    public const string Font = StandardFonts.HELVETICA_BOLD;
    public static readonly Color FillColor = ColorConstants.WHITE;
    public const string VersionNumber = "4.2021";
}

static class Page1
{
    public const int FontSize = 34;
    public static class Version
    {
        public const int X = 735, Y = 248;
    }
}

static class Page2
{
    public const int FontSize = 21;
    public static class Version
    {
        public const int X = 760, Y = 573;
    }
    public static class Disclaimer
    {
        public const float X = 75, Y = 26;
        public const float Width = 883, Height = 81;
    }
    public static class MapImage
    {
        public const string FileName = "PathtoImage.png";
        public const float X = 111.318f, Y = 130.791f;
        public const float Width = 755.454f, Height = 432.094f;
    }
    public static class Paragraph
    {
        public const string Disclaimer = "Text";
        public const string Font = StandardFonts.HELVETICA;
        public static readonly Color FontColor = ColorConstants.BLACK;
        public const int FontSize = 12;
    }
}

UPDATE #1 using statement vs using declaration

Prior C#8 you can not use using declaration but you can use using statements

using (var originalPdfStream = new MemoryStream(buffer))
using (var modifiedPdfStream = new MemoryStream())
{
    var pdfReader = new PdfReader(originalPdfStream);
    var pdfDocument = new PdfDocument(pdfReader, new PdfWriter(modifiedPdfStream));
    
    EditFirstPage(pdfDocument);
    EditSecondPage(pdfDocument);
    
    pdfDocument.Close();
    byte[] modifiedPdfInBytes = modifiedPdfStream.ToArray();
}

I am getting error about using declarations' is not available in C# 7.3. is there another way to write that section of the code? can i just use var originalPdfStream without the using? — Jefferson
– Jefferson, Commented Apr 1, 2022 at 14:11
another question I had was when I do canvas.Add(paragraph); will that add the canvasPage? I am missing the paragraph text i only have the data that is getting added to the canvasPage? — Jefferson
– Jefferson, Commented Apr 1, 2022 at 14:37
@Jefferson I did not touch your logic, so if it worked in your version it should work with the proposed version as well. — Peter Csala
– Peter Csala, Commented Apr 1, 2022 at 14:53

Stack Exchange Network

Adding a PDF file using iText7

1 Answer 1

Main

First page

Second Page

You must log in to answer this question.

Hot Network Questions

Adding a PDF file using iText7

1 Answer 1

Main

First page

Second Page

You must log in to answer this question.

Related

Hot Network Questions