Create custom annotations in Xamarin

1- (void)setCustomImage:(PTAnnot*)annot doc:(PTPDFDoc*)doc
2{
3    // Initialize a new PTElementWriter and PTElementBuilder
4    PTElementWriter* writer = [[PTElementWriter alloc] init];
5    PTElementBuilder* builder = [[PTElementBuilder alloc] init];
6    
7    [writer WriterBeginWithSDFDoc:[doc GetSDFDoc] compress:YES];
8
9    // Initialize the new image
10    PTImage* img = [PTImage Create:[doc GetSDFDoc] filename:[[NSBundle mainBundle] pathForResource:@"image" ofType:@"png"]];
11    int w = [img GetImageWidth], h = [img GetImageHeight];
12
13    // Initialize a new image element
14    PTElement* img_element = [builder CreateImageWithCornerAndScale:img x:0 y:0 hscale:w vscale:h];
15
16    // Write the element
17    [writer WritePlacedElement:img_element];
18
19    // Get the bounding box of the new element
20    PTPDFRect* bbox = [img_element GetBBox];
21
22    // Configure the appearance stream that will be written to the annotation
23    PTObj* appearance_stream = [writer End];
24
25    // Set the bounding box to be the rect of the new element
26	[appearance_stream PutRect:@"BBox" x1:[bbox GetX1] y1:[bbox GetY1] x2:[bbox GetX2] y2:[bbox GetY1]];
27
28    // Overwrite the annotation's appearance with the new appearance stream
29	[annot SetAppearance:appearance_stream annot_state:e_ptnormal app_state:0];
30}

1public void SetCustomImage(Annot annot, PDFDoc doc, string imagePath)
2{
3    // Initialize a new ElementWriter and ElementBuilder
4    ElementWriter writer = new ElementWriter();
5    ElementBuilder builder = new ElementBuilder();
6    writer.Begin(doc.GetSDFDoc(), true);
7    // Initialize the new image
8    Image image = Image.Create(doc.GetSDFDoc(), imagePath);
9    int w = image.GetImageWidth();
10    int h = image.GetImageHeight();
11    // Initialize a new image element
12    Element element = builder.CreateImage(image, 0, 0, w, h);
13    // Write the element
14    writer.WritePlacedElement(element);
15    // Get the bounding box of the new element
16    Rect bbox = new Rect();
17    element.GetBBox(bbox);
18    // Configure the appearance stream that will be written to the annotation
19    Obj new_appearance_stream = writer.End();
20    // Set the bounding box to be the rect of the new element
21    new_appearance_stream.PutRect(
22        "BBox",
23        bbox.x1,
24        bbox.y1,
25        bbox.x2,
26        bbox.y2);
27    // Overwrite the annotation's appearance with the new appearance stream
28    annot.SetAppearance(new_appearance_stream);
29}

1public void setCustomImage(Context context, Annot annot, PDFDoc doc, int imageRes) throws PDFNetException {
2    // Initialize a new ElementWriter and ElementBuilder
3    ElementWriter writer = new ElementWriter();
4    ElementBuilder builder = new ElementBuilder();
5    writer.begin(doc.getSDFDoc(), true);
6    File imageFile = Utils.copyResourceToLocal(context, imageRes, "image", ".png");
7    // Initialize the new image
8    Image image = Image.create(doc.getSDFDoc(), imageFile.getAbsolutePath());
9    int w = image.getImageWidth();
10    int h = image.getImageHeight();
11    // Initialize a new image element
12    Element element = builder.createImage(image, 0, 0, w, h);
13    // Write the element
14    writer.writePlacedElement(element);
15    // Get the bounding box of the new element
16    Rect bbox = element.getBBox();
17    // Configure the appearance stream that will be written to the annotation
18    Obj new_appearance_stream = writer.end();
19    // Set the bounding box to be the rect of the new element
20    new_appearance_stream.putRect(
21        "BBox",
22        bbox.getX1(),
23        bbox.getY1(),
24        bbox.getX2(),
25        bbox.getY2());
26    // Overwrite the annotation's appearance with the new appearance stream
27    annot.setAppearance(new_appearance_stream);
28}

1@Throws(PDFNetException::class)
2fun setCustomImage(context: Context, annot: Annot, doc: PDFDoc, imageRes: Int) {
3    // Initialize a new ElementWriter and ElementBuilder
4    val writer = ElementWriter()
5    val builder = ElementBuilder()
6    writer.begin(doc.sdfDoc, true)
7    val imageFile = Utils.copyResourceToLocal(context, imageRes, "image", ".png")
8    // Initialize the new image
9    val image = Image.create(doc.sdfDoc, imageFile!!.absolutePath)
10    val w = image.imageWidth
11    val h = image.imageHeight
12    // Initialize a new image element
13    val element = builder.createImage(image, 0.0, 0.0, w.toDouble(), h.toDouble())
14    // Write the element
15    writer.writePlacedElement(element)
16    // Get the bounding box of the new element
17    val bbox = element.bBox
18    // Configure the appearance stream that will be written to the annotation
19    val new_appearance_stream = writer.end()
20    // Set the bounding box to be the rect of the new element
21    new_appearance_stream.putRect(
22            "BBox",
23            bbox.x1,
24            bbox.y1,
25            bbox.x2,
26            bbox.y2)
27    // Overwrite the annotation's appearance with the new appearance stream
28    annot.appearance = new_appearance_stream
29}