Add Action Chain to PDF in C#

PDF supports actions. And Spire.PDF, a very powerful .NET component enables developers to add action chain to PDF file. Action chain means an action get executed automatically after another one.

In this article, a solution is introduced to add action chain to PDF file.

Step 1: Set the action that gets performed right after PDF document is opened

[C#]

String script
                = "app.alert({"
                + "    cMsg: \"I'll lead; you must follow me.\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
PdfJavaScriptAction action1 = new PdfJavaScriptAction(script);
document.AfterOpenAction = action1;

Spire.PDF provides you a class called PdfJavaScriptAction that executes JavaScript code. Create a PdfJavaScriptAction instance “action1” using JavaScript code. And set the property AfterOpenAction of “document” to action1.

Step 2: Set the action that gets performed after “action1” using the property NextAction

[C#]

script
                = "app.alert({"
                + "    cMsg: \"The firt page!\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
PdfJavaScriptAction action2 = new PdfJavaScriptAction(script);
action1.NextAction = action2;

Step 3: Set the action that gets performed after “action2”

[C#]

PdfDestination dest = new PdfDestination(pagetwo);
dest.Zoom = 1;
PdfGoToAction action3 = new PdfGoToAction(dest);
action2.NextAction = action3;

PdfDestination can mark a specified page or location in PDF. Create a PdfDestination instance “dest” using “pagetwo”. Then create a PdfGoToAction instance “action3” using “dest”.

Step 4: Set the action that gets performed after “action3”

[C#]

script
                = "app.alert({"
                + "    cMsg: \"Oh sorry, it's the last page. I'm missing!\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
PdfJavaScriptAction action4 = new PdfJavaScriptAction(script);
action3.NextAction = action4;

Step 5: Save the file

[C#]

document.SaveToFile("result.pdf");

Full code:

[C#]

using Spire.Pdf;
using Spire.Pdf.Actions;
using Spire.Pdf.General;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;


namespace AddActionChain
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument document = new PdfDocument();

            PdfPageBase pageone = document.Pages.Add();
            pageone.Canvas.DrawString("This is Page One.",
                                   new PdfFont(PdfFontFamily.Helvetica, 20f),
                                   new PdfSolidBrush(Color.Black),
                                   10, 10);
            PdfPageBase pagetwo = document.Pages.Add();
            pagetwo.Canvas.DrawString("This is Page Two.",
                                   new PdfFont(PdfFontFamily.Helvetica, 20f),
                                   new PdfSolidBrush(Color.Black),
                                   10, 10);

            String script
                = "app.alert({"
                + "    cMsg: \"I'll lead; you must follow me.\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
            PdfJavaScriptAction action1 = new PdfJavaScriptAction(script);
            document.AfterOpenAction = action1;

            script
                = "app.alert({"
                + "    cMsg: \"The first page!\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
            PdfJavaScriptAction action2 = new PdfJavaScriptAction(script);
            action1.NextAction = action2;

            PdfDestination dest = new PdfDestination(pagetwo);
            dest.Zoom = 1;
            PdfGoToAction action3 = new PdfGoToAction(dest);
            action2.NextAction = action3;

            script
                = "app.alert({"
                + "    cMsg: \"Oh sorry, it's the last page. I'm missing!\","
                + "    nIcon: 3,"
                + "    cTitle: \"JavaScript Action\""
                + "});";
            PdfJavaScriptAction action4 = new PdfJavaScriptAction(script);
            action3.NextAction = action4;

            document.SaveToFile("result.pdf");

            System.Diagnostics.Process.Start("result.pdf");
        }
    }
}

Screenshot:

add action chain in pdf

Add Action Chain to PDF in C#

See Also