Added sample for KB How to create a new document with existing document pages in pdfViewer?

Create_NewPDF_From_Exsisting_document_pages/App.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<configuration>
+    <startup> 
+
+    </startup>
+</configuration>

Create_NewPDF_From_Exsisting_document_pages/App.xaml

@@ -0,0 +1,9 @@
+<Application x:Class="PDFViewer_WPF.App"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="clr-namespace:PDFViewer_WPF"
+             StartupUri="MainWindow.xaml">
+    <Application.Resources>
+
+    </Application.Resources>
+</Application>

Create_NewPDF_From_Exsisting_document_pages/App.xaml.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Configuration;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace PDFViewer_WPF
+{
+    /// <summary>
+    /// Interaction logic for App.xaml
+    /// </summary>
+    public partial class App : Application
+    {
+    }
+}

Create_NewPDF_From_Exsisting_document_pages/MainWindow.xaml

@@ -0,0 +1,12 @@
+<Window xmlns:syncfusion="http://schemas.syncfusion.com/wpf"  xmlns:PdfViewer="clr-namespace:Syncfusion.Windows.PdfViewer;assembly=Syncfusion.PdfViewer.WPF"  x:Class="WPF_Sample_FW.MainWindow"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:local="clr-namespace:WPF_Sample_FW"
+        mc:Ignorable="d"
+        Title="MainWindow" Height="450" Width="800">
+    <Grid>
+        <PdfViewer:PdfViewerControl Name="PDFViewer"/>
+    </Grid>
+</Window>

Create_NewPDF_From_Exsisting_document_pages/MainWindow.xaml.cs

@@ -0,0 +1,63 @@
+using Syncfusion.Pdf;
+using Syncfusion.Pdf.Graphics;
+using Syncfusion.Pdf.Parsing;
+using Syncfusion.Pdf.Security;
+using Syncfusion.Windows.PdfViewer;
+using System;
+using System.Drawing;
+using System.IO;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using Bitmap = System.Drawing.Bitmap;
+using Path = System.Windows.Shapes.Path;
+
+namespace WPF_Sample_FW
+{
+    /// <summary>
+    /// Interaction logic for MainWindow.xaml
+    /// </summary>
+    public partial class MainWindow : Window
+    {
+        string filePath = "../../../Data/";
+        public MainWindow()
+        {
+            InitializeComponent();
+
+            //Load a PDF document
+            PdfLoadedDocument ldoc = new PdfLoadedDocument(filePath  + "Input.pdf");
+
+            ldoc.FlattenAnnotations();
+
+            if(ldoc.Form != null && ldoc.Form.Fields.Count > 0)
+                    ldoc.Form.FlattenFields();
+
+            //Create a new instance of PdfDocument class
+            PdfDocument document = new PdfDocument();
+
+            //Set page margin value as 0
+            document.PageSettings.Margins.All = 0;
+
+            //Set page size as A3
+            document.PageSettings.Size = PdfPageSize.A3;
+
+            for (int i = 0; i < ldoc.Pages.Count; i++)
+            {
+                //Get loaded page as template
+                PdfTemplate template = ldoc.Pages[i].CreateTemplate();
+
+                //Create new page
+                PdfPage page = document.Pages.Add();
+
+                //Create Pdf graphics for the page 
+                PdfGraphics g = page.Graphics;
+
+                //Draw template with the size as page size
+                g.DrawPdfTemplate(template, new PointF(0, 0), new SizeF(page.GetClientSize().Width, page.GetClientSize().Height));
+
+            }
+            document.Save( filePath + "Output.pdf");
+            PDFViewer.Load(filePath + "Output.pdf");
+        }
+    }
+}

Create_NewPDF_From_Exsisting_document_pages/PDFViewer_WPF.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Syncfusion.PdfViewer.WPF" Version="*" />
+    <PackageReference Include="System.Drawing.Common" Version="9.0.8" />
+  </ItemGroup>
+  <Import Project="targets\MultiTargeting.targets" /> 
+</Project>

Create_NewPDF_From_Exsisting_document_pages/PDFViewer_WPF.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36401.2
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PDFViewer_WPF", "PDFViewer_WPF.csproj", "{0FAA7523-B034-4EA9-860A-A8936DFFD40E}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{0FAA7523-B034-4EA9-860A-A8936DFFD40E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0FAA7523-B034-4EA9-860A-A8936DFFD40E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0FAA7523-B034-4EA9-860A-A8936DFFD40E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0FAA7523-B034-4EA9-860A-A8936DFFD40E}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {BAAD6341-6945-42C7-8438-919E9DB8EB03}
+	EndGlobalSection
+EndGlobal

Create_NewPDF_From_Exsisting_document_pages/Properties/AssemblyInfo.cs

@@ -0,0 +1,52 @@
+using System.Reflection;
+using System.Resources;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Windows;
+
+// General Information about an assembly is controlled through the following
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+//[assembly: AssemblyTitle("PDFViewer_WPF")]
+//[assembly: AssemblyDescription("")]
+//[assembly: AssemblyConfiguration("")]
+//[assembly: AssemblyCompany("")]
+//[assembly: AssemblyProduct("PDFViewer_WPF")]
+//[assembly: AssemblyCopyright("Copyright ©  2025")]
+//[assembly: AssemblyTrademark("")]
+//[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible
+// to COM components.  If you need to access a type in this assembly from
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+//In order to begin building localizable applications, set
+//<UICulture>CultureYouAreCodingWith</UICulture> in your .csproj file
+//inside a <PropertyGroup>.  For example, if you are using US english
+//in your source files, set the <UICulture> to en-US.  Then uncomment
+//the NeutralResourceLanguage attribute below.  Update the "en-US" in
+//the line below to match the UICulture setting in the project file.
+
+//[assembly: NeutralResourcesLanguage("en-US", UltimateResourceFallbackLocation.Satellite)]
+
+
+//[assembly: ThemeInfo(
+//    ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located
+//                                     //(used if a resource is not found in the page,
+//                                     // or application resource dictionaries)
+//    ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located
+//                                              //(used if a resource is not found in the page,
+//                                              // app, or any theme specific resource dictionaries)
+//)]
+
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version
+//      Build Number
+//      Revision
+//
+//[assembly: AssemblyVersion("1.0.0.0")]
+//[assembly: AssemblyFileVersion("1.0.0.0")]

Create_NewPDF_From_Exsisting_document_pages/Properties/Resources.resx

@@ -0,0 +1,117 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>