pop-up a window from itextsharp annotation to display images and text

问题

I want to add and pop-up window in C# project to display an image and text by clicking on itextsharp annotation.

iTextSharp.text.pdf.PdfAnnotation annot = iTextSharp.text.pdf.PdfAnnotation.CreateLink(stamper.Writer, c.rect, PdfAnnotation.HIGHLIGHT_INVERT, PdfAction.JavaScript("app.alert('action!')", stamper.Writer));

above code is used to display the alert and i want to customize it to my needs can someone please give me an option.i'm not familiar with javascript. or can i use any other options ?

回答1:

You need a couple of annotations to achieve what you want.

Let me start with a simple text annotation:

Suppose that:

writer is your PdfWriter instance,
rect1 and rect2 are rectangles that define coordinates,
title and contents are string objects with the content you want to show in the text annotation,

Then you need this code snippet to add the popup annotations:

// Create the text annotation
PdfAnnotation text = PdfAnnotation.CreateText(writer, rect1, title, contents, false, "Comment");
text.Name = "text";
text.Flags = PdfAnnotation.FLAGS_READONLY | PdfAnnotation.FLAGS_NOVIEW;
// Create the popup annotation
PdfAnnotation popup = PdfAnnotation.CreatePopup(writer, rect2, null, false);
// Add the text annotation to the popup
popup.Put(PdfName.PARENT, text.IndirectReference);
// Declare the popup annotation as popup for the text
text.Put(PdfName.POPUP, popup.IndirectReference);
// Add both annotations
writer.AddAnnotation(text);
writer.AddAnnotation(popup);
// Create a button field
PushbuttonField field = new PushbuttonField(wWriter, rect1, "button");
PdfAnnotation widget = field.Field;
// Show the popup onMouseEnter
PdfAction enter = PdfAction.JavaScript(JS1, writer);
widget.SetAdditionalActions(PdfName.E, enter);
// Hide the popup onMouseExit
PdfAction exit = PdfAction.JavaScript(JS2, writer);
widget.SetAdditionalActions(PdfName.X, exit);
// Add the button annotation
writer.AddAnnotation(widget);

Two constants aren't explained yet:

JS1:

"var t = this.getAnnot(this.pageNum, 'text'); t.popupOpen = true; var w = this.getField('button'); w.setFocus();"

JS2:

"var t = this.getAnnot(this.pageNum, 'text'); t.popupOpen = false;"

This is, of course, explained in my book, more specifically in chapter 7. You can find a full example here. If you need a C# example, please look for the corresponding example here.

If you also want an image, please take a look at this example: advertisement.pdf

Here you have an advertisement that closes when you click "close this advertisement". This is also done using JavaScript. You need to combine the previous snippet with the code of the Advertisement example.

The key JavaScript methods you'll need are: getField() and getAnnot(). You'll have to change the properties to show or hide the content.

回答2:

I solved this problem by using an attachment instead of a popup. Below code will place an image in your pdf, and on click of image, it will open image with full resolution.

PdfReader reader = new PdfReader(ClassLoader.getSystemClassLoader().getResourceAsStream("source.pdf"));
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream("target.pdf"));

PdfAnnotation imgAttach = PdfAnnotation.createFileAttachment(stamper.getWriter(), new Rectangle(100, 100, 200, 200), "", null, "PATH/TO/image.jpeg", "image.jpeg");

PdfAppearance app = stamper.getOverContent(1).createAppearance(100, 100);
Image img = Image.getInstance("PATH/TO/image.jpeg");
img.scaleAbsolute(100, 100);
img.setAbsolutePosition(100, 100);
app.addImage(img);

imgAttach.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, app);

stamper.addAnnotation(imgAttach, 1);
stamper.getOverContent(1).addImage(img);
stamper.close();

来源：https://stackoverflow.com/questions/23968916/pop-up-a-window-from-itextsharp-annotation-to-display-images-and-text

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javascript

itextsharp