/// <summary>
/// Create PDF Document on The Fly in C# using Pdfium.Net SDK Library
/// </summary>
public void CreatePdf()
{// The PDF coordinate system origin is at the bottom left corner of the page. // The X-axis is pointing to the right. The Y-axis is pointing in upward direction.// The sizes and coordinates in this method are given in the inches.// Step 1: Initialize PDF library and create empty document// Return value: PdfDocument main classPdfCommon.Initialize();var doc = PdfDocument.CreateNew();  // Create a PDF document// Step 2: Add new page// Arguments: page width: 8.27", page height: 11.69", Unit of measure: inches//  The PDF unit of measure is point. There are 72 points in one inch.var page = doc.Pages.InsertPageAt(doc.Pages.Count, 8.27f * 72, 11.69f * 72);// Step 3: Add graphics and text contents to the page// Insert image from file using standart System.Drawing.Bitmap classusing (PdfBitmap logo = PdfBitmap.FromFile(@"e:\63\logo_square.png")){PdfImageObject imageObject = PdfImageObject.Create(doc, logo, 0, 0);//image resolution is 300 DPI and location is 1.69 x 10.0 inches.imageObject.Matrix = new FS_MATRIX(logo.Width * 72 / 300, 0, 0, logo.Height * 72 / 300, 1.69 * 72, 10.0 * 72);page.PageObjects.Add(imageObject);}// Create fonts used for text objectsPdfFont calibryBold = PdfFont.CreateFont(doc, "CalibriBold");// Insert text objects at 7.69"; 11.02" and font size is 25PdfTextObject textObject = PdfTextObject.Create("Sample text", 1.69f * 72, 11.02f * 72, calibryBold, 25);textObject.FillColor = FS_COLOR.Black;page.PageObjects.Add(textObject);// Step 5: Generate page content and save pdf file// argument: PDF file namepage.GenerateContent();doc.Save(@"e:\63\sample_document.pdf", SaveFlags.NoIncremental);
}

如何使用 C# 以编程方式从一组图像生成 PDF

/// <summary>
/// Generate PDF document From Multiple Images in C# using PDF Library
/// </summary>
public void GeneratePdf()
{//Initialize C# PDF LibraryPdfCommon.Initialize();//Create a PDF documentusing (var doc = PdfDocument.CreateNew()){//Read imagesvar files = System.IO.Directory.GetFiles(@"c:\Images\", "*.*", System.IO.SearchOption.AllDirectories);foreach (var file in files){//Create empty PdfBitmapusing (PdfBitmap pdfBitmap = PdfBitmap.FromFile(file)){//Create Image objectvar imageObject = PdfImageObject.Create(doc, pdfBitmap, 0, 0);//Calculate size of image in PDF pointsvar size = CalculateSize(pdfBitmap.Width, pdfBitmap.Height);//Add empty page to PDF documentvar page = doc.Pages.InsertPageAt(doc.Pages.Count, size);//Insert image to newly created pagepage.PageObjects.Add(imageObject);//set image matriximageObject.Matrix = new FS_MATRIX(size.Width, 0, 0, size.Height, 0, 0);//Generate PDF page content to content streampage.GenerateContent();}}// Save  PDF document as "saved.pdf" in no incremental modedoc.Save(@"c:\test.pdf", SaveFlags.NoIncremental);}
}
/// <summary>
/// The function takes width and height of the bitmap in pixels as well as
/// horizontal and vertical DPI and calculates the size of the PDF page.
/// To understand the conversion you should know the following:
///     One inch contains exactly 72 PDF points;
///     DPI of the scanned image may vфry and depends on scanning resolution
/// <summary>
private FS_SIZEF CalculateSize(int width, int height, float dpiX=300, float dpiY=300)
{return new FS_SIZEF(){Width = width * 72 / dpiX,Height = height * 72 / dpiY};
}

此示例展示了如何使用简单的 C# 代码和 PDF 库从一堆扫描图像生成 PDF 文档。

/// <summary>
/// Printing PDF Files in C# using PDF Library
/// </summary>
public void PrintPdf()
{var doc = PdfDocument.Load("c:\test.pdf");  // Read PDF filevar printDoc = new PdfPrintDocument(doc);printDoc.Print();
}

public void PrintPdf()
{var doc = PdfDocument.Load("c:\test.pdf");var printDoc = new PdfPrintDocument(doc);PrintController printController = new StandardPrintController();printDoc.PrintController = printController;printDoc.Print(); // C# Print PDF document
}

public void OnPrintClick()
{if (PdfViewer.Document.FormFill != null)PdfViewer.Document.FormFill.ForceToKillFocus();//create an instance of PrintDocument classvar printDoc = new PdfPrintDocument(PdfViewer.Document); // create an instance of Print document class that is used for printing PDF document.//Create a standard print dialog boxvar dlg = new PrintDialog();dlg.AllowCurrentPage = true;dlg.AllowSomePages = true;dlg.UseEXDialog = true;//sets the PrintDocument used to obtain PrinterSettings.dlg.Document = printDoc;//show PrinterDialog and print pdf documentif (dlg.ShowDialog() == DialogResult.OK)printDoc.Print();   // C# Print PDF
}

/// <summary>
/// Read PDF File and Extract Text From it in C#
/// </summary>public void ExtractText()
{//Initialize the SDK library//You have to call this function before you can call any PDF processing functions.PdfCommon.Initialize();//Open and load a PDF document from a file.using (var doc = PdfDocument.Load(@"c:\test001.pdf")) // C# Read PDF File{foreach (var page in doc.Pages){//Gets number of characters in a page or -1 for error.//Generated characters, like additional space characters, new line characters, are also counted.int totalCharCount = page.Text.CountChars;//Extract text from page to the stringstring text = page.Text.GetText(0, totalCharCount);page.Dispose();}}
}

/// <summary>
/// Extract Text Coordinates from Pdf in C# using PDF Library
/// </summary>
public void ExtractTextInfo()
{//Initialize the SDK library//You have to call this function before you can call any PDF processing functions.PdfCommon.Initialize();//Open and load a PDF document from a file.using (var doc = PdfDocument.Load(@"c:\test001.pdf")) // C# Read PDF File{//Get second page from documentusing (var page = doc.Pages[1]){//Extract text information structure from the page// 10 - Index for the start characters// 25 - Number of characters to be extractedvar textInfo = page.Text.GetTextInfo(10, 25);//Gets text from textInfo strtucturestring text = textInfo.Text;//Gets a collection of rectangular areas bounding specified text.var rects = textInfo.Rects;}}
}

如何在 PDF 文件中搜索文本

/// <summary>
/// Search for a Text in a PDF File in C# With Pdfium.Net SDK Library
/// </summary>
public void Search()
{//Open PDF documentusing (var doc = PdfDocument.Load(@"d:\0\test_big.pdf")) // Read PDF document and enumerate pages{//Enumerate pagesforeach(var page in doc.Pages){var found = page.Text.Find("text for search", FindFlags.MatchWholeWord, 0);if (found == null)return; //nothing founddo{var textInfo = found.FoundText;foreach(var rect in textInfo.Rects){float x = rect.left;float y = rect.top;//...}} while (found.FindNext());page.Dispose();}}
}

此示例说明如何使用简单的 C# 代码和 PDF 库在 PDF 文档中搜索文本。

/// <summary>
/// Split PDF in C# using PDF Library
/// </summary>
public void SplitDocument()
{//Initialize the SDK library//You have to call this function before you can call any PDF processing functions.PdfCommon.Initialize();//Open and load a PDF document from a file.using (var sourceDoc = PdfDocument.Load(@"c:\test001.pdf")) // C# Read PDF File{//Create one PDF document for pages 1-5.using (var doc = PdfDocument.CreateNew()){//Import pages from source documentdoc.Pages.ImportPages(sourceDoc, "1-5", 0);//And save it to doc1.pdfdoc.Save(@"c:\doc1.pdf", SaveFlags.Incremental);}//Create another PDF document for pages 5-10.using (var doc = PdfDocument.CreateNew()){//Also import pagesdoc.Pages.ImportPages(sourceDoc, "5-10", 0);//And save them toodoc.Save(@"c:\doc2.pdf", SaveFlags.Incremental);}}
}

/// <summary>
/// Merge PDFs in C# using PDF Library
/// </summary>
public void MergePdf()
{//Initialize the SDK library//You have to call this function before you can call any PDF processing functions.PdfCommon.Initialize();//Open and load a PDF document in which will be merged other filesusing (var mainDoc = PdfDocument.Load(@"c:\test001.pdf")) // C# Read source PDF File #1{//Open one PDF document.using (var doc = PdfDocument.Load(@"c:\doc1.pdf")) //Read PDF File #2{//Import all pages from documentmainDoc.Pages.ImportPages(doc,string.Format("1-{0}", doc.Pages.Count),mainDoc.Pages.Count);}//Open another PDF document.using (var doc = PdfDocument.Load(@"c:\doc2.pdf")){//Import all pages from documentmainDoc.Pages.ImportPages(doc,string.Format("1-{0}", doc.Pages.Count),mainDoc.Pages.Count);}mainDoc.Save(@"c:\ResultDocument.pdf", SaveFlags.NoIncremental);}
}

如何以编程方式从 PDF 字段填充和提取数据

/// <summary>
/// Filling Editable PDF Fields and Extracting Data From Them using .Net PDF Library
/// </summary>
private void btnTest_Click(object sender, RoutedEventArgs e)
{var forms = new PdfForms();var doc = PdfDocument.Load(@"c:\test.pdf", forms); // C# Read PDF Document//doc.FormFill is equal to forms and can be used to get access to acro forms as well;int i = 0;foreach(var field in forms.InterForm.Fields){if(field.FieldType == Patagames.Pdf.Enums.FormFieldTypes.FPDF_FORMFIELD_TEXTFIELD){field.Value = "This is a field #" + (++i);}}
}

此示例代码演示了如何使用 .Net PDF 库以编程方式填写 pdf 文档中的所有可编辑表单。