How to place underline on space string in ITextSharp

Question

How to add under line under a spacebar. It is not adding space under the empty spaces.

I tried with 2-3 example and it failed to add underline under space.

1.

        para = New Paragraph(New Chunk("abc.                ", underlined_font))
        cell = New PdfPCell(para)
        cell.Border = 0
        cell.BorderWidthBottom = 0
        document.Add(cell)

2. Dim str_required_space As New String(" "c, 20)
    para = New Paragraph(New Chunk(str_required_space, underlined_font))
    cell = New PdfPCell(para)
    cell.Border = 0
    cell.BorderWidthBottom = 0
    document.Add(cell)
   

I can't use border of cell as the length of the input string is uncertain. So I am using underline.

Please help to add spaces under space.

My Requirement image

Thanks

[Edit]

If I follow answer 1 then result would be like below

asdasd asdsad scasdnk kjashdk kasbas ckasbd ascuasc ksajcasc 
asdansjdnasjakjsnasndasdmlaskdm  
________________________________________________________________

But I need Below result.

asdasd asdsad scasdnk kjashdk kasbas ckasbd ascuasc ksajcasc 
________________________________________________________________
asdansjdnasjakjsnasndasdmlaskdm  
________________________________________________________________

I tried with Ansii Code. Not working for me :(

        Dim str_required_space As New String(ChrW(32), (119 - (str_synopsis.Length Mod 119)))

        para = New Paragraph(str_required_space)
        cell = New PdfPCell(para)
        cell.Border = 0
        doc.Add(cell)

Answer 1

Please read chapter 2 of my book, more specifically the section about vertical position marks, separators, and tabs (section 2.2.6).

Looking at your image (ignoring the soft porn images on that site, please avoid such links in the future), I think you need a line as shown in figure 2.9 (the line under the names of the directors). The code that results in the PDF shown in that screen shot can be found here.

This is how it's done in Java:

Paragraph p = new Paragraph("abc.");
LineSeparator line = new LineSeparator(1, 100, null, Element.ALIGN_CENTER, -2);
p.add(line);
document.add(p);

It should be a no-brainer to adapt this code to C#. If you do experience problems, then you can find the ported versions of the book samples here.

What did you do wrong in your code?

This doesn't make sense:

para = New Paragraph(New Chunk("abc.                ", underlined_font))

The content of the Chunk is trimmed, which explains why the spaces disappear. An alternative would be to use non-breaking space characters (ASCII code 160) instead of regular space characters (ASCII code 32).

Update

My previous answer was based on your image and it was the correct answer to your initial question. However: you have now changed your question (instead of creating a new question).

You can meet your requirement by using a page event, more specifically, by implementing the OnGenericTag() method. This method is described in chapter 5 of my book.

In Java, the implementation would look like this:

public void onGenericTag(PdfWriter writer, Document pdfDocument,
    Rectangle rect, String text) {
    Rectangle page = pdfDocument.getPageSize();
    float x1 = page.getRight(pdfDocument.rightMargin());
    float x2 = page.getLeft(pdfDocument.leftMargin());
    float y = rect.getBottom() - 3;
    PdfContentByte canvas = writer.getDirectContent();
    canvas.moveTo(x1, y);
    canvas.lineTo(x2, y);
    canvas.stroke();
}

You need to create an instance of the page event with that implementation (e.g. a class that you wrote and that you named MyPageEvent) and declare that page event to the PdfWriter using the setPageEvent() method:

writer.setPageEvent(new MyPageEvent());

You can now declare you Chunk and Paragraph like this:

Chunk chunk = new Chunk(long_text);
chunk.setGenericTag("");
Paragraph p = new Paragraph(chunk);
document.add(p);

It is important that you construct your paragraph with only one Chunk object. If you have more than one Chunk in the paragraph, parts of the line will look thicker.