C# Requires Chilkat v11.7.0+

Get a PDF Field Value by its Label (Value to the Right)

See more PDF Text Extraction Examples

Demonstrates the "label" option, which captures the text that belongs to a caption such as "Invoice Number:" without needing coordinates. With labelValue "right", the value is the rest of the label's line. Label matching ignores case, extra spaces and a trailing colon. C#

bool success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The invoice used in this example is available at invoice_labels.pdf

Chilkat.Pdf pdf = new Chilkat.Pdf();
success = pdf.LoadFile("qa_data/pdf/invoice_labels.pdf");
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();
Chilkat.JsonObject jsonOut = new Chilkat.JsonObject();

//  The invoice has lines such as "Invoice Number:   INV-2026-0412".
//  The label option restricts the "text" operation to the text belonging to the label.
json.UpdateString("label","Invoice Number");

//  "right" means the value is the rest of the label's line.
//  (The default, "auto", uses the rest of the line if there is text there, otherwise the block below.)
json.UpdateString("labelValue","right");

success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

//  The value is returned as the text.
Debug.WriteLine("Invoice Number: " + jsonOut.StringOf("text"));

//  The labelMatches array tells where the label was found and how it appeared in the PDF.
Debug.WriteLine("Found on page " + Convert.ToString(jsonOut.IntOf("labelMatches[0].page")) + " as \"" + jsonOut.StringOf("labelMatches[0].label") + "\"");

//  Matching ignores case and the trailing colon, so these all work:
json.UpdateString("label","CUSTOMER:");
success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("Customer: " + jsonOut.StringOf("text"));

json.UpdateString("label","due date");
success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("Due Date: " + jsonOut.StringOf("text"));

//  The totals at the foot of the invoice are right-aligned labels with the amount beside them.
json.UpdateString("label","Total Due");
success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

Debug.WriteLine("Total Due: " + jsonOut.StringOf("text"));

//  A label that is not found is not an error.  The text is empty, labelMatches is empty,
//  and the quality report has an issue with the code "labelNotFound".
json.UpdateString("label","Tracking Number");
success = pdf.ExtractText("text",json,jsonOut);
if (success == false) {
    Debug.WriteLine(pdf.LastErrorText);
    return;
}

if (jsonOut.SizeOfArray("labelMatches") == 0) {
    Debug.WriteLine("Tracking Number: (not found) " + jsonOut.StringOf("quality.pages[0].issues[0].code"));
}

//  Sample output:

//  Invoice Number: INV-2026-0412
//  Found on page 1 as "Invoice Number:"
//  Customer: Northwind Traders
//  Due Date: April 13, 2026
//  Total Due: $1,234.53
//  Tracking Number: (not found) labelNotFound