VB.NET Requires Chilkat v11.7.0+

Extract PDF Text to a StringBuilder and Save to a File

See more PDF Text Extraction Examples

Demonstrates ExtractTextSb, which writes the extracted text to a StringBuilder instead of returning it as a JSON string. Use it for large documents. The JSON output still receives the quality report. VB.NET

Dim success As Boolean = False

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

'  The PDF used in this example is available at long_report.pdf

Dim pdf As New Chilkat.Pdf
success = pdf.LoadFile("qa_data/pdf/long_report.pdf")
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Number of pages: " & pdf.NumPages)

'  ExtractTextSb takes the same operation and options as ExtractText, but the text
'  goes to a StringBuilder.  This avoids building a very large JSON string for
'  documents with many pages.
Dim json As New Chilkat.JsonObject
Dim sbText As New Chilkat.StringBuilder
Dim jsonOut As New Chilkat.JsonObject

success = pdf.ExtractTextSb("text",json,sbText,jsonOut)
If (success = False) Then
    Debug.WriteLine(pdf.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("Extracted " & sbText.Length & " characters.")

'  Save the text to a file.
success = sbText.WriteFile("qa_output/long_report.txt","utf-8",False)
If (success = False) Then
    Debug.WriteLine(sbText.LastErrorText)
    Exit Sub
End If


'  The JSON output does not contain the text, but it still has the quality report.
Debug.WriteLine("Quality: " & jsonOut.StringOf("quality.rating"))
Debug.WriteLine("Pages with no text (need OCR): [" & jsonOut.StringOf("quality.pagesNeedingOcr") & "]")

'  Sample output:

'  Number of pages: 3
'  Extracted 4522 characters.
'  Quality: good
'  Pages with no text (need OCR): []