BUG: Text That Contains a Single LF or CR in RichTextBox Becomes CR/LF on Windows 2000 (284948)

   Date        Time    Version        Size     File name
   -------------------------------------------------------
   4/16/2001  04:31p   5.30.23.1207   412,432  Riched20.dll 


				

MORE INFORMATION

For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base: For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

Steps to Reproduce Behavior

Scenario 1

1. On a Windows 2000-based computer, open Visual Basic 6.0.
2. Create a new Standard EXE project with the sample code that is provided in the following Microsoft Knowledge Base article:

   146022 HOWTO: Set Up the RichTextBox Control for WYSIWYG Printing

3. Run the project, and load a Unix-formatted TextFile, which uses LF characters only. Under Windows 2000, an infinite loop occurs in the following section of code:

       ' Get length of text in RTF.
       TextLength = Len(RTF.Text)
       
       ' Loop printing each page until done.
       Do
           ' Print the page by sending EM_FORMATRANGE message.
           NextCharPosition = SendMessage(RTF.hWnd, EM_FORMATRANGE, True, fr)
           If NextCharPosition >= TextLength Then
               Exit Do 'If done then exit
           End If
           fr.chrg.cpMin = NextCharPosition ' Starting position for next page
           fr.hdc = Printer.hdc
           fr.hdcTarget = Printer.hdc
       Loop
   						

   SendMessage seems to be operating on the original, unconverted data, while the Len function returns results based on the CR/LF pairs.

Scenario 2

1. On a Windows 2000-based computer, open Visual Basic 6.0.
2. Create a new Standard EXE project. Form1 is created by default.
3. From the Project menu, select Components. In the resultant dialog box, select the Microsoft RichTextBox Control check box, and then click OK. A RichTextBox icon appears on the controls Toolbox on the left.
4. Place a RichTextBox control on Form1.
5. Double-click on Form1 to bring up the code window. Add the following code to Sub Form_Load:

   Dim str As String
   Dim strLastChar As String
   Dim strSecondToLastChar As String
   
   RichTextBox1.Text = "Item" & Chr(10)
   
   ' Cache the richtext string.
   '
   str = RichTextBox1.Text
   
   ' Pull the last and second to last characters.
   '
   strLastChar = Right(str, 1)
   strSecondToLastChar = Mid(str, Len(str) - 1, 1)
   
   ' Display the string length and ASCII.
   '
   MsgBox Len(RichTextBox1.Text) & " " & Asc(strSecondToLastChar) _
      & " " & Asc(strLastChar)
   					

6. Press the F5 key to run the project. The message box displays "6 13 10". The string is 6 characters long and ends in an ASCII 13 (carriage return) and ASCII 10 (line feed) combination. This means that an ASCII 13 character (carriage return) is inserted into the string either at the time the text is set or before it is returned by Riched20.dll.

On Windows NT 4.0 SP6, the string "5 109 10" is returned. The string is 5 characters long and ends in an ASCII 109 "m" and ASCII 10 (line feed) character combination.

Scenario 2 becomes more problematic in the following case:

1. Close Form1 to stop the project.
2. Replace the Form_Load code with the following code:

   RichTextBox1.Text = "Item" & Chr(10)
   RichTextBox1.Span Chr(10), , True
   MsgBox Len(RichTextBox1.SelText)	
   					

3. Press F5 to run the project. SelText has a length of 6 characters: the "Item" string, followed by a carriage return and line feed. On Windows NT 4.0 SP6, the return string contains the 4 characters, "Item", as expected.