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Q154884: HOWTO: Find and Highlight Text in the RichTextBox Control

Article: Q154884
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SUMMARY
=======

In many applications there is a function to search and highlight keywords in a
text window. The RichTextBox control in Visual Basic can be made to provide this
functionality, as shown in the sample code below.

MORE INFORMATION
================

1. Start a new project in Visual Basic. Form1 is created by default.

2. Place a Command button and a RichTextBox on Form1. Set the Text property of
  the RichTextBox to "This is an example of finding text in a rich text box."

3. Add the following code to the General Declarations section of Form1:

        Option Explicit

        Private Sub Command1_Click()
          HighlightWords RichTextBox1, "text", vbRed
        End Sub

        Private Function HighlightWords(rtb As RichTextBox, _
                                    sFindString As String, _
                                    lColor As Long) _
                                    As Integer

          Dim lFoundPos As Long           'Position of first character
                                          'of match
          Dim lFindLength As Long         'Length of string to find
          Dim lOriginalSelStart As Long
          Dim lOriginalSelLength As Long
          Dim iMatchCount As Integer      'Number of matches

          'Save the insertion points current location and length
          lOriginalSelStart = rtb.SelStart
          lOriginalSelLength = rtb.SelLength

          'Cache the length of the string to find
          lFindLength = Len(sFindString)

          'Attempt to find the first match
          lFoundPos = rtb.Find(sFindString, 0, , rtfNoHighlight)
          While lFoundPos > 0
            iMatchCount = iMatchCount + 1

            rtb.SelStart = lFoundPos
            'The SelLength property is set to 0 as
            'soon as you change SelStart
            rtb.SelLength = lFindLength
            rtb.SelColor = lColor

            'Attempt to find the next match
            lFoundPos = rtb.Find(sFindString, _
              lFoundPos + lFindLength, , rtfNoHighlight)
          Wend

          'Restore the insertion point to its original
          'location and length
          rtb.SelStart = lOriginalSelStart
          rtb.SelLength = lOriginalSelLength

          'Return the number of matches
          HighlightWords = iMatchCount

        End Function

4. Choose Start from the Run menu, or press the F5 key to start the project.
  Click the Command button and you should see that both occurrences of the word
  "text" are now shown in red.

REFERENCES
==========

The Visual Basic Online Help and the Professional Features Manual in the Custom
Control Section, p.329-362.

Additional query words: kbVBp400 kbVBp500 kbVBp600 kbVBp kbdsd kbDSupport kbControl kbintluk

======================================================================
Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Version           : :4.0,5.0,6.0
Issue type        : kbhowto

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