How to: Generate a PDF Document Layout with a Watermark from Scratch

• Aug 29, 2024
• 4 minutes to read

Important

You need a license for the DevExpress Office File API Subscription or DevExpress Universal Subscription to use these examples in production code.

This example shows the PDF Document Creation API that is used to programmatically generate a document layout.

• The custom DrawGraphics method draws content inside an empty PDF document.
• The custom AddWatermark method generates a watermark with custom text and adds it to the created PDF document.

When you launch the app, the file is saved to your Documents folder (%userprofile%/Documents).

View Example

Program.cs

using DevExpress.Drawing;
using DevExpress.Pdf;
using System;
using System.Diagnostics;
using System.Drawing;
using System.IO;

namespace DocumentCreationAPI {
    class Program {
        static void Main(string[] args) {

            string docPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments),"Result.pdf");

            using (PdfDocumentProcessor processor = new PdfDocumentProcessor()) {
                // Create an empty document.
                processor.CreateEmptyDocument(docPath);
                // Create and draw PDF graphics.
                using (PdfGraphics graph = processor.CreateGraphics()) {
                    DrawGraphics(graph);
                    // Render a page with graphics.
                    processor.RenderNewPage(PdfPaperSize.Letter, graph);
                }
            }
            // Generate a watermark.
            AddWatermark("Not for sale",docPath,docPath);
            Process.Start(docPath);
        }

        // Draw graphics inside a PDF document.
        static void DrawGraphics(PdfGraphics graph) {
            // Draw text lines on the page. 
            DXSolidBrush black = (DXSolidBrush)DXBrushes.Black;
            DXFont font1 = new DXFont("Times New Roman", 32, DXFontStyle.Bold);
            graph.DrawString("PDF Document Processor", font1, black, 180, 150);

            DXFont font2 = new DXFont("Arial", 20);
            graph.DrawString("Display, Print and Export PDF Documents", font2, black, 168, 230);

            DXFont font3 = new DXFont("Arial", 10);
            graph.DrawString("The PDF Document Processor is a non-visual component " +
                              "that provides the application programming interface of the PDF Viewer.", font3, black, 16, 300);
        }

        // Add a watermark with custom text.
        static void AddWatermark(string text,string fileName,string resultFileName) {
            using (PdfDocumentProcessor documentProcessor = new PdfDocumentProcessor()) {
                string fontName = "Arial Black";
                int fontSize = 12;
                PdfStringFormat stringFormat = PdfStringFormat.GenericTypographic;
                stringFormat.Alignment = PdfStringAlignment.Center;
                stringFormat.LineAlignment = PdfStringAlignment.Center;
                documentProcessor.LoadDocument(fileName);
                using (DXSolidBrush brush = new DXSolidBrush(Color.FromArgb(63,Color.Black))) {
                    DXFont font = new DXFont(fontName,fontSize);
                    foreach (var page in documentProcessor.Document.Pages) {
                        var watermarkSize = page.CropBox.Width * 0.75;
                        using (PdfGraphics graphics = documentProcessor.CreateGraphics()) {
                            SizeF stringSize = graphics.MeasureString(text,font);
                            float scale = (float)(watermarkSize / (double)stringSize.Width);
                            graphics.TranslateTransform((float)(page.CropBox.Width * 0.5),(float)(page.CropBox.Height * 0.5));
                            graphics.RotateTransform((float)-45.0);
                            graphics.TranslateTransform((float)(-stringSize.Width * scale * 0.5),(float)(-stringSize.Height * scale * 0.5));
                            DXFont actualFont = new DXFont(fontName,fontSize * scale);
                            RectangleF rect = new RectangleF(0,0,stringSize.Width * scale,stringSize.Height * scale);
                            graphics.DrawString(text,actualFont,brush,rect,stringFormat);

                            graphics.AddToPageForeground(page,72,72);
                        }
                    }                    
                }
                documentProcessor.SaveDocument(resultFileName);
            }
        }
    }
}

Program.vb

Imports DevExpress.Drawing
Imports DevExpress.Pdf
Imports System
Imports System.Diagnostics
Imports System.Drawing
Imports System.IO

Namespace DocumentCreationAPI

    Friend Class Program

        Shared Sub Main(ByVal args As String())

            Dim docPath As String = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "Result.pdf")

            Using processor As PdfDocumentProcessor = New PdfDocumentProcessor()
                ' Create an empty document.
                processor.CreateEmptyDocument(docPath)
                ' Create and draw PDF graphics.
                Using graph As PdfGraphics = processor.CreateGraphics()
                    DrawGraphics(graph)
                    ' Render a page with graphics.
                    processor.RenderNewPage(PdfPaperSize.Letter, graph)
                End Using
            End Using
            ' Generate a watermark.
            AddWatermark("Not for sale", docPath, docPath)
            Process.Start(docPath)
        End Sub

        ' Draw graphics inside a PDF document.
        Private Shared Sub DrawGraphics(ByVal graph As PdfGraphics)
            ' Draw text lines on the page. 
            Dim black As DXSolidBrush = CType(DXBrushes.Black, DXSolidBrush)
            Dim font1 As DXFont = New DXFont("Times New Roman", 32, DXFontStyle.Bold)
            graph.DrawString("PDF Document Processor", font1, black, 180, 150)

            Dim font2 As DXFont = New DXFont("Arial", 20)
            graph.DrawString("Display, Print and Export PDF Documents", font2, black, 168, 230)

            Dim font3 As DXFont = New DXFont("Arial", 10)
            graph.DrawString("The PDF Document Processor is a non-visual component " & "that provides the application programming interface of the PDF Viewer.", font3, black, 16, 300)
        End Sub

        ' Add a watermark with custom text.
        Private Shared Sub AddWatermark(Text As String, fileName As String, resultFileName As String)
            Using documentProcessor As New PdfDocumentProcessor()
                Dim fontName As String = "Arial Black"
                Dim fontSize As Integer = 12
                Dim stringFormat As PdfStringFormat = PdfStringFormat.GenericTypographic
                stringFormat.Alignment = PdfStringAlignment.Center
                stringFormat.LineAlignment = PdfStringAlignment.Center
                documentProcessor.LoadDocument(fileName)
                Using brush As New SolidBrush(Color.FromArgb(63, Color.Black))
                    Using font As New Font(fontName, fontSize)
                        For Each page In documentProcessor.Document.Pages
                            Dim watermarkSize = page.CropBox.Width * 0.75
                            Using graphics As PdfGraphics = documentProcessor.CreateGraphics()
                                Dim stringSize As SizeF = graphics.MeasureString(Text, font)
                                Dim scale As Single = CSng(watermarkSize) / stringSize.Width
                                graphics.TranslateTransform(CSng(page.CropBox.Width * 0.5), CSng(page.CropBox.Height * 0.5))
                                graphics.RotateTransform(-45.0)
                                graphics.TranslateTransform(CSng(-stringSize.Width * scale * 0.5), CSng(-stringSize.Height * scale * 0.5))
                                Using actualFont As Font = New Font(fontName, fontSize * scale)
                                    Dim rect As RectangleF = New RectangleF(0, 0, stringSize.Width * scale, stringSize.Height * scale)
                                    graphics.DrawString(Text, actualFont, brush, rect, stringFormat)
                                End Using
                                graphics.AddToPageForeground(page, 72, 72)
                            End Using
                        Next
                    End Using
                End Using
                documentProcessor.SaveDocument(resultFileName)
            End Using
        End Sub
    End Class
End Namespace