使用ItextSharp在PDF中绘制图像上的线条

Question

I am trying to draw lines on image that needs to be loaded on pdf document, just like we draw graphics on paint event of any control, but it fails to do so.

Any Suggestions ?

Document pdfDoc = new Document(PageSize.A2, 10f, 10f, 10f, 0f);
pdfDoc.AddHeader("Batting Report - ", txtSearchBox.Text);

iTextSharp.text.Image pic = iTextSharp.text.Image.GetInstance(Properties.Resources.bgWW
                        , System.Drawing.Imaging.ImageFormat.Jpeg);


PdfWriter writer = PdfWriter.GetInstance(pdfDoc, stream);
pdfDoc.Open();

pdfDoc.Add(pic);

So, how do I modify the pic object of ItextSharpImage so that it can draw lines on the image?

Answer 1

Please take a look at the WatermarkedImages4 example. It is based on the WatermarkedImages1 example I referred to in the comments. The only different between the two examples is that we add text in the example written in answer to How to add text to an image? whereas we add lines in the example written in answer to your question.

We add images like this:

document.add(getWatermarkedImage(cb, Image.getInstance(IMAGE1)));

The getWatermarkedImage() method looks like this:

public Image getWatermarkedImage(PdfContentByte cb, Image img) throws DocumentException {
    float width = img.getScaledWidth();
    float height = img.getScaledHeight();
    PdfTemplate template = cb.createTemplate(width, height);
    template.addImage(img, width, 0, 0, height, 0, 0);
    template.saveState();
    template.setColorStroke(BaseColor.GREEN);
    template.setLineWidth(3);
    template.moveTo(width * .25f, height * .25f);
    template.lineTo(width * .75f, height * .75f);
    template.moveTo(width * .25f, height * .75f);
    template.lineTo(width * .25f, height * .25f);
    template.stroke();
    template.setColorStroke(BaseColor.WHITE);
    template.ellipse(0, 0, width, height);
    template.stroke();
    template.restoreState();
    return Image.getInstance(template);
}

As you can see, I add two green lines using moveTo() , lineTo() and stroke() . I also add a white ellipse using the ellipse() and stroke() method.

This results in a PDF that looks like this:

As you can see, the shape of the ellipse and the position of the lines are different for the different images because I defined my coordinates based on the width and the height of the image.