如何在C#中編輯PDF

var pdf = new PdfDocument("report.pdf");
var renderer = new ChromePdfRenderer();
var coverPagePdf = renderer.RenderHtmlAsPdf("<h1>Cover Page</h1><hr>");
pdf.PrependPdf(coverPagePdf);
pdf.SaveAs("report_with_cover.pdf");

Dim pdf = New PdfDocument("report.pdf")
Dim renderer = New ChromePdfRenderer()
Dim coverPagePdf = renderer.RenderHtmlAsPdf("<h1>Cover Page</h1><hr>")
pdf.PrependPdf(coverPagePdf)
pdf.SaveAs("report_with_cover.pdf")

var pdf = new PdfDocument("report.pdf");
// Copy pages 5 to 7 and save them as a new document.
pdf.CopyPages(4, 6).SaveAs("report_highlight.pdf");

Dim pdf = New PdfDocument("report.pdf")
' Copy pages 5 to 7 and save them as a new document.
pdf.CopyPages(4, 6).SaveAs("report_highlight.pdf")

var pdf = new PdfDocument("report.pdf");

// Remove the last page from the PDF and save again
pdf.RemovePage(pdf.PageCount - 1);
pdf.SaveAs("report_minus_one_page.pdf");

Dim pdf = New PdfDocument("report.pdf")

' Remove the last page from the PDF and save again
pdf.RemovePage(pdf.PageCount - 1)
pdf.SaveAs("report_minus_one_page.pdf")

var pdfs = new List<PdfDocument>
{
    PdfDocument.FromFile("A.pdf"),
    PdfDocument.FromFile("B.pdf"),
    PdfDocument.FromFile("C.pdf")
};

PdfDocument mergedPdf = PdfDocument.Merge(pdfs);
mergedPdf.SaveAs("merged.pdf");

foreach (var pdf in pdfs)
{
    pdf.Dispose();
}

Dim pdfs = New List(Of PdfDocument) From {PdfDocument.FromFile("A.pdf"), PdfDocument.FromFile("B.pdf"), PdfDocument.FromFile("C.pdf")}

Dim mergedPdf As PdfDocument = PdfDocument.Merge(pdfs)
mergedPdf.SaveAs("merged.pdf")

For Each pdf In pdfs
	pdf.Dispose()
Next pdf

var pdf = new PdfDocument("sample.pdf");

// Take the first page
var pdf_page1 = pdf.CopyPage(0);
pdf_page1.SaveAs("Split1.pdf");

// Take the pages 2 & 3
var pdf_page2_3 = pdf.CopyPages(1, 2);
pdf_page2_3.SaveAs("Spli2t.pdf");

Dim pdf = New PdfDocument("sample.pdf")

' Take the first page
Dim pdf_page1 = pdf.CopyPage(0)
pdf_page1.SaveAs("Split1.pdf")

' Take the pages 2 & 3
Dim pdf_page2_3 = pdf.CopyPages(1, 2)
pdf_page2_3.SaveAs("Spli2t.pdf")

// Open an Encrypted File, alternatively create a new PDF from Html
var pdf = PdfDocument.FromFile("encrypted.pdf", "password");

// Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto";
pdf.MetaData.Keywords = "SEO, Friendly";
pdf.MetaData.ModifiedDate = System.DateTime.Now;

// Edit file security settings
// The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption();
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key");
pdf.SecuritySettings.AllowUserAnnotations = false;
pdf.SecuritySettings.AllowUserCopyPasteContent = false;
pdf.SecuritySettings.AllowUserFormData = false;
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights;

// Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret"; // password to edit the pdf
pdf.SecuritySettings.UserPassword = "shareable";  // password to open the pdf
pdf.SaveAs("secured.pdf");

Imports System

' Open an Encrypted File, alternatively create a new PDF from Html
Dim pdf = PdfDocument.FromFile("encrypted.pdf", "password")

' Edit file metadata
pdf.MetaData.Author = "Satoshi Nakamoto"
pdf.MetaData.Keywords = "SEO, Friendly"
pdf.MetaData.ModifiedDate = DateTime.Now

' Edit file security settings
' The following code makes a PDF read only and will disallow copy & paste and printing
pdf.SecuritySettings.RemovePasswordsAndEncryption()
pdf.SecuritySettings.MakePdfDocumentReadOnly("secret-key")
pdf.SecuritySettings.AllowUserAnnotations = False
pdf.SecuritySettings.AllowUserCopyPasteContent = False
pdf.SecuritySettings.AllowUserFormData = False
pdf.SecuritySettings.AllowUserPrinting = IronPdf.Security.PdfPrintSecurity.FullPrintRights

' Change or set the document encryption password
pdf.SecuritySettings.OwnerPassword = "top-secret" ' password to edit the pdf
pdf.SecuritySettings.UserPassword = "shareable" ' password to open the pdf
pdf.SaveAs("secured.pdf")

using IronPdf;
using IronPdf.Signing;


new IronPdf.Signing.PdfSignature("Iron.p12", "123456").SignPdfFile("any.pdf");

Imports IronPdf
Imports IronPdf.Signing


Call (New IronPdf.Signing.PdfSignature("Iron.p12", "123456")).SignPdfFile("any.pdf")

using IronPdf;

// Step 1. Create a PDF
var renderer = new ChromePdfRenderer();
var doc = renderer.RenderHtmlAsPdf("<h1>Testing 2048 bit digital security</h1>");

// Step 2. Create a Signature.
// You may create a .pfx or .p12 PDF signing certificate using Adobe Acrobat Reader.
// Read: https://helpx.adobe.com/acrobat/using/digital-ids.html
var signature = new IronPdf.Signing.PdfSignature("Iron.pfx", "123456")
{
    // Step 3. Optional signing options and a handwritten signature graphic
    SigningContact = "support@ironsoftware.com",
    SigningLocation = "Chicago, USA",
    SigningReason = "To show how to sign a PDF"
};

//Step 4. Sign the PDF with the PdfSignature. Multiple signing certificates may be used
doc.Sign(signature);

//Step 5. The PDF is not signed until saved to file, steam or byte array.
doc.SaveAs("signed.pdf");

Imports IronPdf

' Step 1. Create a PDF
Private renderer = New ChromePdfRenderer()
Private doc = renderer.RenderHtmlAsPdf("<h1>Testing 2048 bit digital security</h1>")

' Step 2. Create a Signature.
' You may create a .pfx or .p12 PDF signing certificate using Adobe Acrobat Reader.
' Read: https://helpx.adobe.com/acrobat/using/digital-ids.html
Private signature = New IronPdf.Signing.PdfSignature("Iron.pfx", "123456") With {
	.SigningContact = "support@ironsoftware.com",
	.SigningLocation = "Chicago, USA",
	.SigningReason = "To show how to sign a PDF"
}

'Step 4. Sign the PDF with the PdfSignature. Multiple signing certificates may be used
doc.Sign(signature)

'Step 5. The PDF is not signed until saved to file, steam or byte array.
doc.SaveAs("signed.pdf")

var Renderer = new ChromePdfRenderer();
var myPdf = Renderer.RenderHtmlFileAsPdf("my-content.html");

// Here we can add an attachment with a name and byte[]
var attachment1 = myPdf.Attachments.AddAttachment("attachment_1", example_attachment);

// And here is an example of removing an attachment
myPdf.Attachments.RemoveAttachment(attachment1);

myPdf.SaveAs("my-content.pdf");

Dim Renderer = New ChromePdfRenderer()
Dim myPdf = Renderer.RenderHtmlFileAsPdf("my-content.html")

' Here we can add an attachment with a name and byte[]
Dim attachment1 = myPdf.Attachments.AddAttachment("attachment_1", example_attachment)

' And here is an example of removing an attachment
myPdf.Attachments.RemoveAttachment(attachment1)

myPdf.SaveAs("my-content.pdf")

var pdf = new PdfDocument("document.pdf");

// Quality parameter can be 1-100, where 100 is 100% of original quality
pdf.CompressImages(60);
pdf.SaveAs("document_compressed.pdf");

Dim pdf = New PdfDocument("document.pdf")

' Quality parameter can be 1-100, where 100 is 100% of original quality
pdf.CompressImages(60)
pdf.SaveAs("document_compressed.pdf")

var pdf = new PdfDocument("document.pdf");

pdf.CompressImages(90, true);
pdf.SaveAs("document_scaled_compressed.pdf");

Dim pdf = New PdfDocument("document.pdf")

pdf.CompressImages(90, True)
pdf.SaveAs("document_scaled_compressed.pdf")

var renderer = new ChromePdfRenderer();

// Build a footer using html to style the text
// mergeable fields are:
// {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}
renderer.RenderingOptions.HtmlFooter = new HtmlHeaderFooter()
{
    MaxHeight = 15, //millimeters
    HtmlFragment = "<center><i>{page} of {total-pages}<i></center>",
    DrawDividerLine = true
};

// Build a header using an image asset
// Note the use of BaseUrl to set a relative path to the assets
renderer.RenderingOptions.HtmlHeader = new HtmlHeaderFooter()
{
    MaxHeight = 20, //millimeters
    HtmlFragment = "<img src='logo.png'>",
    BaseUrl = new System.Uri(@"C:\assets\images").AbsoluteUri
};

Dim renderer = New ChromePdfRenderer()

' Build a footer using html to style the text
' mergeable fields are:
' {page} {total-pages} {url} {date} {time} {html-title} & {pdf-title}
renderer.RenderingOptions.HtmlFooter = New HtmlHeaderFooter() With {
	.MaxHeight = 15,
	.HtmlFragment = "<center><i>{page} of {total-pages}<i></center>",
	.DrawDividerLine = True
}

' Build a header using an image asset
' Note the use of BaseUrl to set a relative path to the assets
renderer.RenderingOptions.HtmlHeader = New HtmlHeaderFooter() With {
	.MaxHeight = 20,
	.HtmlFragment = "<img src='logo.png'>",
	.BaseUrl = (New System.Uri("C:\assets\images")).AbsoluteUri
}

var renderer = new ChromePdfRenderer
{
    RenderingOptions =
    {
        FirstPageNumber = 1, // use 2 if a cover-page  will be appended

        // Add a header to every page easily:
        TextHeader =
        {
            DrawDividerLine = true,
            CenterText = "{url}",
            Font = IronSoftware.Drawing.FontTypes.Helvetica,
            FontSize = 12
        },

        // Add a footer too:
        TextFooter =
        {
            DrawDividerLine = true,
            Font = IronSoftware.Drawing.FontTypes.Arial,
            FontSize = 10,
            LeftText = "{date} {time}",
            RightText = "{page} of {total-pages}"
        }
    }
};

Dim renderer = New ChromePdfRenderer With {
	.RenderingOptions = {
		FirstPageNumber = 1, TextHeader = {
			DrawDividerLine = True,
			CenterText = "{url}",
			Font = IronSoftware.Drawing.FontTypes.Helvetica,
			FontSize = 12
		},
		TextFooter = {
			DrawDividerLine = True,
			Font = IronSoftware.Drawing.FontTypes.Arial,
			FontSize = 10,
			LeftText = "{date} {time}",
			RightText = "{page} of {total-pages}"
		}
	}
}

// Create a new PDF or edit an existing document.
PdfDocument pdf = PdfDocument.FromFile("existing.pdf");

// Add bookmark
pdf.Bookmarks.AddBookMarkAtEnd("Author's Note", 2);
pdf.Bookmarks.AddBookMarkAtEnd("Table of Contents", 3);

// Store new bookmark in a variable to add nested bookmarks to
var summaryBookmark = pdf.Bookmarks.AddBookMarkAtEnd("Summary", 17);

// Add a sub-bookmark within the summary
var conclusionBookmark = summaryBookmark.Children.AddBookMarkAtStart("Conclusion", 18);

// Add another bookmark to end of highest-level bookmark list
pdf.Bookmarks.AddBookMarkAtEnd("References", 20);

pdf.SaveAs("existing.pdf");

' Create a new PDF or edit an existing document.
Dim pdf As PdfDocument = PdfDocument.FromFile("existing.pdf")

' Add bookmark
pdf.Bookmarks.AddBookMarkAtEnd("Author's Note", 2)
pdf.Bookmarks.AddBookMarkAtEnd("Table of Contents", 3)

' Store new bookmark in a variable to add nested bookmarks to
Dim summaryBookmark = pdf.Bookmarks.AddBookMarkAtEnd("Summary", 17)

' Add a sub-bookmark within the summary
Dim conclusionBookmark = summaryBookmark.Children.AddBookMarkAtStart("Conclusion", 18)

' Add another bookmark to end of highest-level bookmark list
pdf.Bookmarks.AddBookMarkAtEnd("References", 20)

pdf.SaveAs("existing.pdf")

// create a new PDF or load and edit an existing document.
var pdf = PdfDocument.FromFile("existing.pdf");

// Create a PDF annotation object
var textAnnotation = new IronPdf.Annotations.TextAnnotation(PageIndex: 0)
{
    Title = "This is the major title",
    Contents = "This is the long 'sticky note' comment content...",
    Subject = "This is a subtitle",
    Opacity = 0.9,
    Printable = false,
    Hidden = false,
    OpenByDefault = true,
    ReadOnly = false,
    Rotatable = true,
};

// Add the annotation "sticky note" to a specific page and location within any new or existing PDF.
pdf.Annotations.Add(textAnnotation);

pdf.SaveAs("existing.pdf");

' create a new PDF or load and edit an existing document.
Dim pdf = PdfDocument.FromFile("existing.pdf")

' Create a PDF annotation object
Dim textAnnotation = New IronPdf.Annotations.TextAnnotation(PageIndex:= 0) With {
	.Title = "This is the major title",
	.Contents = "This is the long 'sticky note' comment content...",
	.Subject = "This is a subtitle",
	.Opacity = 0.9,
	.Printable = False,
	.Hidden = False,
	.OpenByDefault = True,
	.ReadOnly = False,
	.Rotatable = True
}

' Add the annotation "sticky note" to a specific page and location within any new or existing PDF.
pdf.Annotations.Add(textAnnotation)

pdf.SaveAs("existing.pdf")

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf");
pdf.AddBackgroundPdf(@"MyBackground.pdf");
pdf.AddForegroundOverlayPdfToPage(0, @"MyForeground.pdf", 0);
pdf.SaveAs(@"C:\Path\To\Complete.pdf");

Dim renderer = New ChromePdfRenderer()
Dim pdf = renderer.RenderUrlAsPdf("https://www.nuget.org/packages/IronPdf")
pdf.AddBackgroundPdf("MyBackground.pdf")
pdf.AddForegroundOverlayPdfToPage(0, "MyForeground.pdf", 0)
pdf.SaveAs("C:\Path\To\Complete.pdf")

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>");

TextStamper stamper1 = new TextStamper
{
    Text = "Hello World! Stamp One Here!",
    FontFamily = "Bungee Spice",
    UseGoogleFont = true,
    FontSize = 100,
    IsBold = true,
    IsItalic = true,
    VerticalAlignment = VerticalAlignment.Top
};

TextStamper stamper2 = new TextStamper()
{
    Text = "Hello World! Stamp Two Here!",
    FontFamily = "Bungee Spice",
    UseGoogleFont = true,
    FontSize = 30,
    VerticalAlignment = VerticalAlignment.Bottom
};

Stamper[] stampersToApply = { stamper1, stamper2 };
pdf.ApplyMultipleStamps(stampersToApply);
pdf.ApplyStamp(stamper2);

Dim renderer = New ChromePdfRenderer()
Dim pdf = renderer.RenderHtmlAsPdf("<h1>Example HTML Document!</h1>")

Dim stamper1 As New TextStamper With {
	.Text = "Hello World! Stamp One Here!",
	.FontFamily = "Bungee Spice",
	.UseGoogleFont = True,
	.FontSize = 100,
	.IsBold = True,
	.IsItalic = True,
	.VerticalAlignment = VerticalAlignment.Top
}

Dim stamper2 As New TextStamper() With {
	.Text = "Hello World! Stamp Two Here!",
	.FontFamily = "Bungee Spice",
	.UseGoogleFont = True,
	.FontSize = 30,
	.VerticalAlignment = VerticalAlignment.Bottom
}

Dim stampersToApply() As Stamper = { stamper1, stamper2 }
pdf.ApplyMultipleStamps(stampersToApply)
pdf.ApplyStamp(stamper2)

var pdf = new PdfDocument("/attachments/2022_Q1_sales.pdf");

ImageStamper logoImageStamper = new ImageStamper("/assets/logo.png");

// Apply to every page, one page, or some pages
pdf.ApplyStamp(logoImageStamper);
pdf.ApplyStamp(logoImageStamper, 0);
pdf.ApplyStamp(logoImageStamper, new[] { 0, 3, 11 });

Dim pdf = New PdfDocument("/attachments/2022_Q1_sales.pdf")

Dim logoImageStamper As New ImageStamper("/assets/logo.png")

' Apply to every page, one page, or some pages
pdf.ApplyStamp(logoImageStamper)
pdf.ApplyStamp(logoImageStamper, 0)
pdf.ApplyStamp(logoImageStamper, { 0, 3, 11 })

var renderer = new ChromePdfRenderer();
var pdf = renderer.RenderHtmlAsPdf("<p>Hello World, example HTML body.</p>");

HtmlStamper stamper = new HtmlStamper($"<p>Example HTML Stamped</p><div style='width:250pt;height:250pt;background-color:red;'></div>")
{
    HorizontalOffset = new Length(-3, MeasurementUnit.Inch),
    VerticalAlignment = VerticalAlignment.Bottom
};

pdf.ApplyStamp(stamper);

Dim renderer = New ChromePdfRenderer()
Dim pdf = renderer.RenderHtmlAsPdf("<p>Hello World, example HTML body.</p>")

Dim stamper As New HtmlStamper($"<p>Example HTML Stamped</p><div style='width:250pt;height:250pt;background-color:red;'></div>")
If True Then
'INSTANT VB WARNING: An assignment within expression was extracted from the following statement:
'ORIGINAL LINE: HorizontalOffset = new Length(-3, MeasurementUnit.Inch), VerticalAlignment = VerticalAlignment.Bottom
	New Length(-3, MeasurementUnit.Inch), VerticalAlignment = VerticalAlignment.Bottom
	HorizontalOffset = New Length(-3, MeasurementUnit.Inch), VerticalAlignment
End If

pdf.ApplyStamp(stamper)

BarcodeStamper bcStamp = new BarcodeStamper("IronPDF", BarcodeEncoding.Code39);

bcStamp.HorizontalAlignment = HorizontalAlignment.Left;
bcStamp.VerticalAlignment = VerticalAlignment.Bottom;

var pdf = new PdfDocument("example.pdf");
pdf.ApplyStamp(bcStamp);

Dim bcStamp As New BarcodeStamper("IronPDF", BarcodeEncoding.Code39)

bcStamp.HorizontalAlignment = HorizontalAlignment.Left
bcStamp.VerticalAlignment = VerticalAlignment.Bottom

Dim pdf = New PdfDocument("example.pdf")
pdf.ApplyStamp(bcStamp)

BarcodeStamper qrStamp = new BarcodeStamper("IronPDF", BarcodeEncoding.QRCode);

qrStamp.Height = 50; // pixels
qrStamp.Width = 50; // pixels

qrStamp.HorizontalAlignment = HorizontalAlignment.Left;
qrStamp.VerticalAlignment = VerticalAlignment.Bottom;

var pdf = new PdfDocument("example.pdf");
pdf.ApplyStamp(qrStamp);

Dim qrStamp As New BarcodeStamper("IronPDF", BarcodeEncoding.QRCode)

qrStamp.Height = 50 ' pixels
qrStamp.Width = 50 ' pixels

qrStamp.HorizontalAlignment = HorizontalAlignment.Left
qrStamp.VerticalAlignment = VerticalAlignment.Bottom

Dim pdf = New PdfDocument("example.pdf")
pdf.ApplyStamp(qrStamp)

var pdf = new PdfDocument("/attachments/design.pdf");
string html = "<h1> Example Title <h1/>";
int rotation = 0;
int watermarkOpacity = 30;

pdf.ApplyWatermark(html, rotation, watermarkOpacity);

Dim pdf = New PdfDocument("/attachments/design.pdf")
Dim html As String = "<h1> Example Title <h1/>"
Dim rotation As Integer = 0
Dim watermarkOpacity As Integer = 30

pdf.ApplyWatermark(html, rotation, watermarkOpacity)

var pdf = new PdfDocument("/assets/example.pdf");

// Apply one stamp to all pages
pdf.ApplyStamp(myStamper);

// Apply one stamp to a specific page
pdf.ApplyStamp(myStamper, 0);

// Apply one stamp to specific pages
pdf.ApplyStamp(myStamper, new[] { 0, 3, 5 });

// Apply a stamp array to all pages
pdf.ApplyMultipleStamps(stampArray);

// Apply a stamp array to a specific page
pdf.ApplyMultipleStamps(stampArray, 0);

// Apply a stamp array to specific pages
pdf.ApplyMultipleStamps(stampArray, new[] { 0, 3, 5 });

// And some Async versions of the above
await pdf.ApplyStampAsync(myStamper, 4);
await pdf.ApplyMultipleStampsAsync(stampArray);

// Additional Watermark apply method
string html = "<h1> Example Title <h1/>";
int rotation = 0;
int watermarkOpacity = 30;
pdf.ApplyWatermark(html, rotation, watermarkOpacity);

Dim pdf = New PdfDocument("/assets/example.pdf")

' Apply one stamp to all pages
pdf.ApplyStamp(myStamper)

' Apply one stamp to a specific page
pdf.ApplyStamp(myStamper, 0)

' Apply one stamp to specific pages
pdf.ApplyStamp(myStamper, { 0, 3, 5 })

' Apply a stamp array to all pages
pdf.ApplyMultipleStamps(stampArray)

' Apply a stamp array to a specific page
pdf.ApplyMultipleStamps(stampArray, 0)

' Apply a stamp array to specific pages
pdf.ApplyMultipleStamps(stampArray, { 0, 3, 5 })

' And some Async versions of the above
Await pdf.ApplyStampAsync(myStamper, 4)
Await pdf.ApplyMultipleStampsAsync(stampArray)

' Additional Watermark apply method
Dim html As String = "<h1> Example Title <h1/>"
Dim rotation As Integer = 0
Dim watermarkOpacity As Integer = 30
pdf.ApplyWatermark(html, rotation, watermarkOpacity)

new Length(value: 5, unit: MeasurementUnit.Inch); // 5 inches

new Length(value: 25, unit: MeasurementUnit.Pixel);// 25px

new Length(); // 0% of the page dimension because value is defaulted to zero and unit is defaulted to percentage

new Length(value: 20); // 20% of the page dimension

Dim tempVar As New Length(value:= 5, unit:= MeasurementUnit.Inch) ' 5 inches

Dim tempVar2 As New Length(value:= 25, unit:= MeasurementUnit.Pixel) ' 25px

Dim tempVar3 As New Length() ' 0% of the page dimension because value is defaulted to zero and unit is defaulted to percentage

Dim tempVar4 As New Length(value:= 20) ' 20% of the page dimension

HtmlStamper logoStamper = new HtmlStamper
{
    VerticalOffset = new Length(15, MeasurementUnit.Percentage),
    HorizontalOffset = new Length(1, MeasurementUnit.Inch)
    // set other properties...
};

Dim logoStamper As New HtmlStamper With {
	.VerticalOffset = New Length(15, MeasurementUnit.Percentage),
	.HorizontalOffset = New Length(1, MeasurementUnit.Inch)
}

// Step 1.  Creating a PDF with editable forms from HTML using form and input tags
const string formHtml = @"
    <html>
        <body>
            <h2>Editable PDF  Form</h2>
            <form>
              First name: <br> <input type='text' name='firstname' value=''> <br>
              Last name: <br> <input type='text' name='lastname' value=''>
            </form>
        </body>
    </html>";

// Instantiate Renderer
var renderer = new ChromePdfRenderer();
renderer.RenderingOptions.CreatePdfFormsFromHtml = true;
renderer.RenderHtmlAsPdf(formHtml).SaveAs("BasicForm.pdf");

// Step 2. Reading and Writing PDF form values.
var formDocument = PdfDocument.FromFile("BasicForm.pdf");

// Read the value of the "firstname" field
var firstNameField = formDocument.Form.FindFormField("firstname");

// Read the value of the "lastname" field
var lastNameField = formDocument.Form.FindFormField("lastname");

' Step 1.  Creating a PDF with editable forms from HTML using form and input tags
Const formHtml As String = "
    <html>
        <body>
            <h2>Editable PDF  Form</h2>
            <form>
              First name: <br> <input type='text' name='firstname' value=''> <br>
              Last name: <br> <input type='text' name='lastname' value=''>
            </form>
        </body>
    </html>"

' Instantiate Renderer
Dim renderer = New ChromePdfRenderer()
renderer.RenderingOptions.CreatePdfFormsFromHtml = True
renderer.RenderHtmlAsPdf(formHtml).SaveAs("BasicForm.pdf")

' Step 2. Reading and Writing PDF form values.
Dim formDocument = PdfDocument.FromFile("BasicForm.pdf")

' Read the value of the "firstname" field
Dim firstNameField = formDocument.Form.FindFormField("firstname")

' Read the value of the "lastname" field
Dim lastNameField = formDocument.Form.FindFormField("lastname")

var formDocument = PdfDocument.FromFile("BasicForm.pdf");

// Set and Read the value of the "firstname" field
var firstNameField = formDocument.Form.FindFormField("firstname");
firstNameField.Value = "Minnie";
Console.WriteLine("FirstNameField value: {0}", firstNameField.Value);

// Set and Read the value of the "lastname" field
var lastNameField = formDocument.Form.FindFormField("lastname");
lastNameField.Value = "Mouse";
Console.WriteLine("LastNameField value: {0}", lastNameField.Value);

formDocument.SaveAs("FilledForm.pdf");

Dim formDocument = PdfDocument.FromFile("BasicForm.pdf")

' Set and Read the value of the "firstname" field
Dim firstNameField = formDocument.Form.FindFormField("firstname")
firstNameField.Value = "Minnie"
Console.WriteLine("FirstNameField value: {0}", firstNameField.Value)

' Set and Read the value of the "lastname" field
Dim lastNameField = formDocument.Form.FindFormField("lastname")
lastNameField.Value = "Mouse"
Console.WriteLine("LastNameField value: {0}", lastNameField.Value)

formDocument.SaveAs("FilledForm.pdf")