问题
I'm trying to create a PDF document that is essentially a list of users in a table format. I need the table to have checkboxes in it. So far, I have the table and the checkboxes separately but I cannot find a way to get the checkboxes in the table. I think I need to add them using the AddCell() method.
Here is my code:
static void Main(string[] args)
{
// create the document, filestream, writer
Document doc = new Document(PageSize.LETTER);
FileStream file = new FileStream(@"C:\Users\test\User List.pdf", FileMode.OpenOrCreate);
PdfWriter writer = PdfWriter.GetInstance(doc, file);
try
{
// metadata
doc.AddAuthor("Test User");
doc.AddCreator("Test Document");
doc.AddKeywords("Test Document");
doc.AddSubject("Test Document");
doc.AddTitle("Test Document - Test User");
// open up the PDF document
doc.Open();
PdfContentByte cb = writer.DirectContent;
Font _bf = new Font(Font.FontFamily.HELVETICA, 9);
// create a table
PdfPTable table = new PdfPTable(3);
PdfPCell cell = new PdfPCell(new Phrase("User List"));
PdfFormField field = PdfFormField.CreateCheckBox(writer);
field.SetWidget(new Rectangle(40, 500, 60, 530), PdfAnnotation.HIGHLIGHT_INVERT);
field.SetFieldFlags(PdfAnnotation.FLAGS_PRINT);
field.FieldName = "Delete";
writer.AddAnnotation(field);
cell.Colspan = 3;
cell.HorizontalAlignment = 0; //0 = left, 1 = center, 2 = right
cell.VerticalAlignment = 1;
table.AddCell("No.");
table.AddCell("Users");
table.AddCell("Delete");
// create form fields
PdfAppearance[] onOff = new PdfAppearance[2];
Rectangle rect;
PdfFormField checkbox;
RadioCheckField _checkbox;
onOff[0] = cb.CreateAppearance(10, 10);
onOff[0].Rectangle(1, 1, 8, 8);
onOff[0].Stroke();
onOff[1] = cb.CreateAppearance(10, 10);
onOff[1].SetRGBColorFill(255, 128, 128);
onOff[1].Rectangle(1, 1, 8, 8);
onOff[1].FillStroke();
onOff[1].MoveTo(1, 1);
onOff[1].LineTo(9, 9);
onOff[1].MoveTo(1, 9);
onOff[1].LineTo(9, 1);
onOff[1].Stroke();
for (int i = 0; i < 5; i++)
{
table.AddCell(i.ToString());
table.AddCell("User " + i);
//rect = new Rectangle(400, 675 - i*40, 415, 663 - i*40);
rect = new Rectangle(400, 735 - i * 40, 415, 723 - i * 40);
_checkbox = new RadioCheckField(writer, rect, "User "+(i+1), "Yes");
checkbox = _checkbox.CheckField;
checkbox.SetAppearance(PdfAnnotation.APPEARANCE_NORMAL, "Off", onOff[0]);
checkbox.SetAppearance(PdfAnnotation.APPEARANCE_NORMAL, "On", onOff[1]);
writer.AddAnnotation(checkbox);
// this is where I am trying to add the checkbox to the table
// what can I add to AddCell() to make the checkbox show up?
table.AddCell();
//ColumnText.ShowTextAligned(cb, Element.ALIGN_LEFT, new Phrase("User " + (i + 1), _bf), 50, 665 - i * 40, 0);
}
cb = writer.DirectContent;
doc.Add(table);
}
catch(DocumentException dex)
{
throw (dex);
}
finally
{
// close
doc.Close();
writer.Close();
file.Close();
}
}
Is there any way to do this using iTextSharp? Maybe there is a better library to use?
回答1:
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();
}
}
}
来源：https://stackoverflow.com/questions/19407179/adding-form-elements-to-a-table-with-itextsharp