【前言】

向文档添加注释,是一种比较常用的向读者传递某些重要信息的手段。通过编程的方式来添加PDF注释,我们可以自定义注释的外观、类型及其他一些个性化的设置,这种可供选择的操作在编程中提供了更多的实用性。因此,本篇文章将介绍添加几种不同类型的PDF注释的方法。下面的示例中,借助控件总结了一些不同类型的注释的具体操作,主要包含以下几种

  • 添加弹出式注释(Popup Annotation)
  • 添加自由文本注释(Free Text Annotation)
  • 添加链接式注释(Link Annotation)
  • 添加多边形注释(Polygon Annotation)
  • 添加线性注释(Line Annotation)

【工具使用】


【代码操作】

1.弹出式注释(Popup Annotation)

C#

using Spire.Pdf;
using Spire.Pdf.General.Find;
using System.Drawing;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;

namespace Annotation_PDF
{
    class Program
    {
        static void Main(string[] args)
        {
            //初始化PdfDocument类实例,并加载测试文档            
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("sample.pdf");

            //获取第一页
            PdfPageBase page = doc.Pages[0];

            //调用方法FindText()查找需要添加注释的字符串
            PdfTextFind[] results = page.FindText("IPCC").Finds;

            //指定注释添加的位置
            float x = results[0].Position.X - doc.PageSettings.Margins.Top;
            float y = results[0].Position.Y - doc.PageSettings.Margins.Left + results[0].Size.Height - 23;

            //创建弹出式注释
            RectangleF rect = new RectangleF(x, y, 10, 0);
            PdfPopupAnnotation popupAnnotation = new PdfPopupAnnotation(rect); 

            //添加注释内容,并设置注释的图标类型和颜色 
            popupAnnotation.Text = "IPCC,This is a scientific and intergovernmental body under the auspices of the United Nations.";
            popupAnnotation.Icon = PdfPopupIcon.Help; 
            popupAnnotation.Color = Color.DarkOliveGreen;

            //添加注释到文件
            page.AnnotationsWidget.Add(popupAnnotation);

            //保存并打开文档
            doc.SaveToFile("Annotation.pdf");
            System.Diagnostics.Process.Start("Annotation.pdf");
        }
    }
}

在选择注释标签类型时,有以下几种类型可供选择
C# 添加PDF注释(5种类型)
注释添加效果:
C# 添加PDF注释(5种类型)

2. 自由文本注释(Free Text Annotation)

C#

using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace FreeTextAnnotation_pdf
{
    class Program
    {
        static void Main(string[] args)
        {
            //创建PdfDocument类对象,加载测试文档
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("sample.pdf");

            PdfPageBase page = doc.Pages[0];
            //初始化RectangleF类,指定注释添加的位置、注释图标大小
            RectangleF rect = new RectangleF(50, 500, 100, 40);
            PdfFreeTextAnnotation textAnnotation = new PdfFreeTextAnnotation(rect);

            //添加注释内容
            textAnnotation.Text = "This is just a sample, please refer the original article to see more!";

            //设置注释属性,包括字体、字号、注释边框粗细、边框颜色、填充颜色等
            PdfFont font = new PdfFont(PdfFontFamily.TimesRoman, 9);
            PdfAnnotationBorder border = new PdfAnnotationBorder(0.75f);
            textAnnotation.Font = font;
            textAnnotation.Border = border;
            textAnnotation.BorderColor = Color.White;
            textAnnotation.LineEndingStyle = PdfLineEndingStyle.Circle;
            textAnnotation.Color = Color.Transparent;
            textAnnotation.Opacity = 0.8f;
            //添加注释到页面
            page.AnnotationsWidget.Add(textAnnotation);

            //保存并打开文档
            doc.SaveToFile("FreeTextAnnotation.pdf", FileFormat.PDF);
            System.Diagnostics.Process.Start("FreeTextAnnotation.pdf");
         }
    }
}

添加效果
C# 添加PDF注释(5种类型)

3. 链接式注释(Link Annotation)

C#

using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace FreeTextAnnotation_pdf
{
    class Program
    {
        static void Main(string[] args)
        {
            //创建PdfDocument类对象,加载测试文档
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("sample.pdf");

            PdfPageBase page = doc.Pages[0];
            //初始化RectangleF类,指定注释添加的位置、注释图标大小
            RectangleF rect = new RectangleF(50, 500, 100, 40);
            PdfFreeTextAnnotation textAnnotation = new PdfFreeTextAnnotation(rect);

            //添加注释内容
            textAnnotation.Text = "This is just a sample, Click here to read the original file!";

            //设置注释属性,包括字体、字号、注释边框粗细、边框颜色、填充颜色等
            PdfFont font = new PdfFont(PdfFontFamily.TimesRoman, 9);
            PdfAnnotationBorder border = new PdfAnnotationBorder(0.75f);
            textAnnotation.Font = font;
            textAnnotation.Border = border;
            textAnnotation.BorderColor = Color.White;
            textAnnotation.LineEndingStyle = PdfLineEndingStyle.Circle;
            textAnnotation.Color = Color.Transparent;

            //添加需要链接到的文件地址,并添加链接到注释
            string filePath = @"C:\Users\Administrator\Desktop\original.pdf";
            PdfFileLinkAnnotation link = new PdfFileLinkAnnotation(rect, filePath);
            page.AnnotationsWidget.Add(link);

            //添加注释到页面
            page.AnnotationsWidget.Add(textAnnotation);

            //保存并打开文档
            doc.SaveToFile("LinkAnnotation.pdf", FileFormat.PDF);
            System.Diagnostics.Process.Start("LinkAnnotation.pdf");
        }
    }
}

添加效果:
C# 添加PDF注释(5种类型)

4. 多边形注释(Polygon Annotation)

C#

using Spire.Pdf;
using Spire.Pdf.Annotations;
using System;
using System.Drawing;

namespace PolygonAnnotation_PDF
{
    class Program
    {
        static void Main(string[] args)
        {
            //创建PdfDocument类对象,加载测试文档
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("sample.pdf");
            //获取文档第一页
            PdfPageBase page = pdf.Pages[0];

            //实例化PdfPolygonAnnotation类,指定多边形各顶点位置
            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)});  

            //指定多边形注释的边框颜色、注释内容、作者、边框类型、修订时间等属性
            polygon.Color = Color.CornflowerBlue;
            polygon.Text = "This article is created by Mia, permit read ONLY.";
            polygon.Author = "Editor's Note";
            polygon.Subject = "polygon annotation demo";
            polygon.BorderEffect = PdfBorderEffect.BigCloud;
            polygon.ModifiedDate = DateTime.Now;

            //添加注释到页面
            page.AnnotationsWidget.Add(polygon);
            //保存并打开文档
            pdf.SaveToFile("Polygon_Annotation.pdf");
            System.Diagnostics.Process.Start("Polygon_Annotation.pdf");
        }
    }
}

添加效果:
C# 添加PDF注释(5种类型)

5. 线性注释(Line Annotation)

C#

using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Fields;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace LineAnnotation_PDF
{
    class Program
    {
        static void Main(string[] args)
        {
            //实例化PdfDocument类,加载文档
            PdfDocument document = new PdfDocument();
            document.LoadFromFile("sample.pdf");
            PdfPageBase page = document.Pages[0];

            //在页面指定位置绘制Line类型注释,并添加注释的文本内容
            int[] linePoints = new int[] { 100,300, 180, 300 };
            PdfLineAnnotation lineAnnotation = new PdfLineAnnotation(linePoints, "Comment Text");

            //设置线条粗细、指向
            lineAnnotation.lineBorder.BorderStyle = PdfBorderStyle.Solid;
            lineAnnotation.lineBorder.BorderWidth = 1;
            lineAnnotation.LineIntent = PdfLineIntent.LineDimension;

            //设置线性注释的头、尾形状、flag类型
            lineAnnotation.BeginLineStyle = PdfLineEndingStyle.Circle;
            lineAnnotation.EndLineStyle = PdfLineEndingStyle.Diamond;
            lineAnnotation.Flags = PdfAnnotationFlags.Default;

            //设置注释颜色
            lineAnnotation.InnerLineColor = new PdfRGBColor(Color.Green);
            lineAnnotation.BackColor = new PdfRGBColor(Color.Green);

            lineAnnotation.LeaderLineExt = 0;
            lineAnnotation.LeaderLine = 0;

            //添加注释到页面
            page.AnnotationsWidget.Add(lineAnnotation);

            //保存并打开文档
            document.SaveToFile("LineAnnotation.pdf");
            System.Diagnostics.Process.Start("LineAnnotation.pdf");

        }
    }
}

添加效果:
C# 添加PDF注释(5种类型)
以上为全部内容。如需转载,请注明出处!
感谢阅读。