BUG: RichTextBox Horizontal Scroll Bar Does Not Always Appear

ID: Q175501

The information in this article applies to:

Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions for Windows, version 5.0
Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 32-bit only, for Windows, version 4.0

SYMPTOMS

The horizontal scrollbar on the RichTextBox does not always appear as expected. If the LoadFile method is used to load a document into a RichTextBox and that document has a line of text that is slightly wider than the width of the RichTextBox, and if that line is located well below the bottom margin of the RichTextBox, the horizontal scroll bar will fail to appear.

RESOLUTION

After loading the contents of the file into the RichTextBox, read them out into a string variable using the TextRTF property and then read them back into the RichTextBox. The Horizontal Scroll Bar will then appear as expected. The code for this workaround follows:


   Dim x As String
   x = RichTextBox2.TextRTF
   RichTextBox2.TextRTF = x

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

Because the sizing of the RichTextBoxes is critical to reproduce this bug, this code sample sites and sizes all of the controls automatically. All you have to do is double-click on the Toolbox buttons to put each control on the form and then follow the instructions. It is not necessary to size or move any of the controls yourself.

Start a new Standard EXE project in Visual Basic 5.0.

Put two RichTextBoxes (RichTextBox1 and RichTextBox2), two Labels (Label1 and Label2) and two CommandButtons (Command1 and Command2) on the form.

Set the Scrollbars property of both RichTextBoxes to "3 - rtfBoth."

Paste the following code into the General Declarations section of the form:


      Option Explicit
      Private Sub Command1_Click()
        'This line is the core of the problem, loading text
        'into an RTF box from a file using LoadFile can cause
        'unexpected scroll bar behavior

        RichTextBox2.LoadFile ("C:\TestRTF")

        '**********************************************
        'All the rest of the code is to attempt to set up a demo
        'which will reproduce the problem on any screen resolution
        '**********************************************

        'Create informational text for Label1
        Dim Caption2 As String
        Caption2 = "The text in the RTF box below is the same as above.  "
        Caption2 = Caption2 & "It was pulled out of the box above, "
        Caption2 = Caption2 & "saved to a file, then loaded into the box "
        Caption2 = Caption2 & "below. Notice the absence of a horizontal "
        Caption2 = Caption2 & "scroll bar."
        Label2.Caption = Caption2
      End Sub

      Private Sub Command2_Click()
        'These three lines of code provide a workaround
        Dim x As String
        x = RichTextBox2.TextRTF
        RichTextBox2.TextRTF = x
      End Sub

      Private Sub Form_Load()
        'Size, position, and set captions for everything
        Form1.Height = 5925
        Label1.Move 120, 120, 4000, 975
        Label2.Move 120, 2640, 4000, 855
        Label2.Caption = ""
        RichTextBox1.Move 120, 1200, 4000, 1215
        RichTextBox2.Move 120, 3600, 4000, 1215
        Command1.Move 120, 4920, 1215, 495
        Command1.Caption = "Load Text"
        Command2.Move 1560, 4920, 1215, 495
        Command2.Caption = "Workaround"

        'set fonts for Form1 and RichTextBox1
        Form1.Font = "Times New Roman"
        RichTextBox1.Font = "Times New Roman"

        'create informational text for Label
        Dim Caption1 As String
        Caption1 = "The text that appears below was read in as a string.  "
        Caption1 = Caption1 & "Notice that the horizontal scroll bar "
        Caption1 = Caption1 & "appears.  This is because one of the lines "
        Caption1 = Caption1 & "of text is wider than the RTFbox"
        Caption1 = Caption1 & " (you have to scroll down to see this "
        Caption1 = Caption1 & "line).This behavior is expected."
        Label1.Caption = Caption1

        'populate RichTextBox1 with the most of the text
        Dim Msg As String
        Msg = "This is to test the horizontal scroll bars "
        Msg = Msg & "on the RichTextBox" & vbCrLf
        Dim i As Integer
           For i = 1 To 20
             Msg = Msg & "Scroll Down" & vbCrLf
           Next i

        'Size the RichTextBoxes to be slightly wider than the
        'first line of text and slightly shorter than the last
        'line of text
        RichTextBox1.Width = Form1.TextWidth(Msg) * 1.1
        RichTextBox2.Width = RichTextBox1.Width

        'size the form and labels to agree with size of RichTextBoxes
        Form1.Width = RichTextBox1.Width + 360
        Label1.Width = RichTextBox1.Width
        Label2.Width = RichTextBox1.Width

        'Add a line to the text that is slightly wider than the
        'RichTextBoxes
        Msg = Msg & "This is to test the horizontal scroll bars "
        Msg = Msg & "on the RichTextBox" & "zzzzz"

        'clear RichTextBox2
        RichTextBox2.TextRTF = ""

        'create an rtf file exactly like the text of the
        'first rtfbox
        RichTextBox1.TextRTF = Msg
        RichTextBox1.SaveFile ("C:\TestRTF")
      End Sub

      Private Sub Form_Resize()
        RichTextBox1.Width = Form1.Width - 360
        RichTextBox2.Width = Form1.Width - 360
      End Sub

Run the project.

The first RichTextBox will display the text as well as the horizontal and vertical scroll bars. This is expected because one of the lines of text is wider than the width of the RichTextBox.

Click on the "Load Text" button, which will save the contents of RichTextBox1 in a .rtf file and then load that file into RichTextBox2. Note that the horizontal scrollbar does not appear.

Click on the Workaround button, which will read the contents of RichTextBox2 (including rtf codes) into a string variable and then read them back into RichTextBox2. The horizontal scrollbar should now appear.

Keywords : kbVBp400 kbVBp500 kbGrpVB VB4WIN kb32bitOnly
Version : WINDOWS:4.0,5.0
Platform : WINDOWS
Issue type : kbbug