''' <summary>
''' Outputs the information about specified word in content of PDF document.
''' </summary>
''' <param name="document">PDF document where word should be searched.</param>
''' <param name="word">Word to search.</param>
Public Sub SearchWordInTextOfPdfDocument(document As Vintasoft.Imaging.Pdf.PdfDocument, word As String)
    System.Console.WriteLine("Searching the word in text of PDF document is started.")

    For i As Integer = 0 To document.Pages.Count - 1
        Dim textRegions As Vintasoft.Imaging.Text.TextRegion() = SimpleTextSearchOnPdfPage(document.Pages(i), word)
        If textRegions IsNot Nothing Then
            For j As Integer = 0 To textRegions.Length - 1
                System.Console.WriteLine(String.Format("- Text={0}, Rectangle={1}", textRegions(j).TextContent, textRegions(j).Rectangle))
            Next
        End If
    Next

    System.Console.WriteLine("Searching the word in text of PDF document is finished.")
End Sub

''' <summary>
''' Searches a text string on PDF page.
''' </summary>
''' <param name="page">PDF page where text should be searched.</param>
''' <param name="text">Text to search.</param>
''' <returns>An array of text regions on PDF page where text was found.</returns>
Public Function SimpleTextSearchOnPdfPage(page As Vintasoft.Imaging.Pdf.Tree.PdfPage, text As String) As Vintasoft.Imaging.Text.TextRegion()
    Dim textRegions As New System.Collections.Generic.List(Of Vintasoft.Imaging.Text.TextRegion)()

    Dim textRegion As Vintasoft.Imaging.Text.TextRegion = Nothing
    Dim startIndex As Integer = 0
    Do
        ' search text
        textRegion = page.TextRegion.FindText(text, startIndex, False)
        ' if found text is not empty
        If textRegion IsNot Nothing Then
            ' add result
            textRegions.Add(textRegion)
            ' shitf start index
            startIndex += textRegion.TextContent.Length
        End If
    Loop While textRegion IsNot Nothing

    Return textRegions.ToArray()
End Function

/// <summary>
/// Outputs the information about specified word in content of PDF document.
/// </summary>
/// <param name="document">PDF document where word should be searched.</param>
/// <param name="word">Word to search.</param>
public void SearchWordInTextOfPdfDocument(Vintasoft.Imaging.Pdf.PdfDocument document, string word)
{
    System.Console.WriteLine("Searching the word in text of PDF document is started.");

    for (int i = 0; i < document.Pages.Count; i++)
    {
        Vintasoft.Imaging.Text.TextRegion[] textRegions = 
            SimpleTextSearchOnPdfPage(document.Pages[i], word);
        if (textRegions != null)
        {
            for (int j = 0; j < textRegions.Length; j++)
            {
                System.Console.WriteLine(string.Format("- Text={0}, Rectangle={1}",
                    textRegions[j].TextContent,
                    textRegions[j].Rectangle));
            }
        }
    }

    System.Console.WriteLine("Searching the word in text of PDF document is finished.");
}

/// <summary>
/// Searches a text string on PDF page.
/// </summary>
/// <param name="page">PDF page where text should be searched.</param>
/// <param name="text">Text to search.</param>
/// <returns>An array of text regions on PDF page where text was found.</returns>
public Vintasoft.Imaging.Text.TextRegion[] SimpleTextSearchOnPdfPage(
    Vintasoft.Imaging.Pdf.Tree.PdfPage page, string text)
{
    System.Collections.Generic.List<Vintasoft.Imaging.Text.TextRegion> textRegions = 
        new System.Collections.Generic.List<Vintasoft.Imaging.Text.TextRegion>();

    Vintasoft.Imaging.Text.TextRegion textRegion = null;
    int startIndex = 0;
    do
    {
        // search text
        textRegion = page.TextRegion.FindText(text, ref startIndex, false);
        // if found text is not empty
        if (textRegion != null)
        {
            // add result
            textRegions.Add(textRegion);
            // shitf start index
            startIndex += textRegion.TextContent.Length;
        }
    } while (textRegion != null);

    return textRegions.ToArray();
}