Polygon annotations are displayed as a series of connected vertices and can be double-clicked to display its note. Users can customize the shape of polygon by setting the vertex coordinates. This article will introduce how to add a polygon annotation to PDF using Spire.PDF.
Step 1: Create a PDF document object, add a new page.
PdfDocument pdf = new PdfDocument(); PdfPageBase page = pdf.Pages.Add();
Step 2: Initialize an instance of PdfPolygonAnnotation, specifying all vertex coordinates which can form a complete shape.
PdfPolygonAnnotation polygon = new PdfPolygonAnnotation(page, new PointF[] { new PointF(0, 30), new PointF(30, 15), new PointF(60, 30), new PointF(45, 50), new PointF(15, 50), new PointF(0, 30)});
Step 3: Set the border color, text, border effect and other properties of polygon annotation.
polygon.Color = Color.PaleVioletRed; polygon.Text = "This is a polygon annotation"; polygon.Author = "E-ICEBLUE"; polygon.Subject = "polygon annotation demo"; polygon.BorderEffect = PdfBorderEffect.BigCloud; polygon.ModifiedDate = DateTime.Now;
Step 4: Add the annotation to PDF page and save the document.
page.Annotations.Add(polygon); pdf.SaveToFile("Polygon_Annotation.pdf");
Result:
Full Code:
[C#]
using Spire.Pdf; using Spire.Pdf.Annotations; using System; using System.Drawing; namespace PolygonAnnotation { class Program { static void Main(string[] args) { PdfDocument pdf = new PdfDocument(); PdfPageBase page = pdf.Pages.Add(); PdfPolygonAnnotation polygon = new PdfPolygonAnnotation(page, new PointF[] { new PointF(0, 30), new PointF(30, 15), new PointF(60, 30), new PointF(45, 50), new PointF(15, 50), new PointF(0, 30)}); polygon.Color = Color.PaleVioletRed; polygon.Text = "This is a polygon annotation"; polygon.Author = "E-ICEBLUE"; polygon.Subject = "polygon annotation demo"; polygon.BorderEffect = PdfBorderEffect.BigCloud; polygon.ModifiedDate = DateTime.Now; page.Annotations.Add(polygon); pdf.SaveToFile("Polygon_Annotation.pdf"); } } }
[VB.NET]
Imports Spire.Pdf Imports Spire.Pdf.Annotations Imports System.Drawing Namespace PolygonAnnotation Class Program Private Shared Sub Main(args As String()) Dim pdf As New PdfDocument() Dim page As PdfPageBase = pdf.Pages.Add() Dim polygon As New PdfPolygonAnnotation(page, New PointF() {New PointF(0, 30), New PointF(30, 15), New PointF(60, 30), New PointF(45, 50), New PointF(15, 50), New PointF(0, 30)}) polygon.Color = Color.PaleVioletRed polygon.Text = "This is a polygon annotation" polygon.Author = "E-ICEBLUE" polygon.Subject = "polygon annotation demo" polygon.BorderEffect = PdfBorderEffect.BigCloud polygon.ModifiedDate = DateTime.Now page.Annotations.Add(polygon) pdf.SaveToFile("Polygon_Annotation.pdf") End Sub End Class End Namespace