I'll reference the iText website showing how to pass a field to a custom IPdfPCellEvent
implementation and how to create that that custom class and recreate it below in C#.
First, create a class the implements the IPdfPCellEvent
:
public class ChildFieldEvent : IPdfPCellEvent {
/** A parent field to which a child field has to be added. */
protected PdfFormField parent;
/** The child field that has to be added */
protected PdfFormField kid;
/** The padding of the field inside the cell */
protected float padding;
/**
* Creates a ChildFieldEvent.
* @param parent the parent field
* @param kid the child field
* @param padding a padding
*/
public ChildFieldEvent(PdfFormField parent, PdfFormField kid, float padding) {
this.parent = parent;
this.kid = kid;
this.padding = padding;
}
/**
* Add the child field to the parent, and sets the coordinates of the child field.
*/
public void CellLayout(PdfPCell cell, iTextSharp.text.Rectangle rect, PdfContentByte[] cb) {
parent.AddKid(kid);
kid.SetWidget(new iTextSharp.text.Rectangle(
rect.GetLeft(padding),
rect.GetBottom(padding),
rect.GetRight(padding),
rect.GetTop(padding)
),
PdfAnnotation.HIGHLIGHT_INVERT
);
}
}
Then just set the CellEvent
on any cells that should have fields in them.
//File to create
var testFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "test.pdf");
//Standard PDF creation, nothing special here
using (var fs = new FileStream(testFile, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (var doc = new Document()) {
using (var writer = PdfWriter.GetInstance(doc, fs)) {
doc.Open();
//Create a root form object that we'll add "children" to. This way we don't have to add each "child" annotation to the writer
var root = PdfFormField.CreateEmpty(writer);
root.FieldName = "root";
//Create a two column table
var t = new PdfPTable(2);
//Add a basic cell
t.AddCell("First Name");
//Create our textfield, the rectangle that we're passing in is ignored and doesn't matter
var tf = new TextField(writer, new iTextSharp.text.Rectangle(0, 0), "first-name");
//Create a new cell
var cell = new PdfPCell();
//Set the cell event to our custom IPdfPCellEvent implementation
cell.CellEvent = new ChildFieldEvent(root, tf.GetTextField(), 1);
//Add the cell to our table
t.AddCell(cell);
//Add the table to the document
doc.Add(t);
//IMPORTANT! Add the root annotation to the writer which also adds all of the child annotations
writer.AddAnnotation(root);
//Clean up
doc.Close();
}
}
}