Q180887 - FIX: File Control's EOF Property Is Always Set to False

FIX: File Control's EOF Property Is Always Set to False

Q180887

The information in this article applies to:

Microsoft Windows CE Toolkit for Visual Basic 5.0, version 1.0

SYMPTOMS

When using the File Control and reading from a file using either the LineInputString or InputFields methods, the EOF property is always False, even when it has reached the end of the file. One of the following error messages will be generated:

An error was encountered while running this program.

-or-

-2147467259

CAUSE

The file EOF property is not set to True when the file pointer reaches the end of the file.

RESOLUTION

There are two options for resolving this issue in the Windows CE Toolkit for Visual Basic 5.0:

Option1

Obtain the Windows CE ActiveX Control Pack available from the Microsoft Web site located at:

http://www.microsoft.com/windowsce/downloads/pccompanions/actxconpak1.asp

Option 2

Instead of checking the EOF property of the File control, use the LOC property and compare it against the LOF property. For example:


   While File1.LOC < File1.LOF
      'put code here
   Wend

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products that are listed at the beginning of this article.

This problem was corrected in Windows CE Toolkit for Visual Basic 6.0.

MORE INFORMATION

Steps to Reproduce Behavior

NOTE: This example uses the LineInputString method. The error also occurs using the InputFields method.

Start a new Windows CE project in Visual Basic 5.0. Form1 is created by default.

Add a File control, two CommandButton controls, and a TextBox to Form1.

Set the Text1.Multiline property to True.

Add the following code:


      Option Explicit

      Private Sub Form_Load()
         Command1.Caption = "Write to file"
         Command2.Caption = "Read from File"
      End Sub

      Private Sub Command1_Click()
         'Write file via LinePrint
         File1.Open "\test.txt", 2
         File1.LinePrint "line one"
         File1.LinePrint "line two"
         File1.LinePrint "line three"
         File1.Close
      End Sub

      Private Sub Command2_Click()
         'Read file via LineInputString
         Dim sLine
         On Error Resume Next
         Text1.Text = ""
         File1.Open "\test.txt", 1
         Do Until File1.EOF
            sLine = File1.LineInputString
            If Err.Number <> 0 Then
               Text1.Text = Text1.Text & "error: " &  _
               Err.Number & " " & Err.Description & vbCrLf
               File1.Close
               Exit Sub
            End If
            Text1.Text = Text1.Text & sLine & ":  File1.EOF = " _
                         & File1.EOF & vbCrLf
         Loop
         File1.Close
      End Sub

Press the F5 key to run the project and note that the error -2147467259 is encountered because File1.EOF is never set to True.

REFERENCES

Books Online for Microsoft Windows CE Toolkit for Visual Basic 5.0

Additional query words: wce vbce vbce5 vbce6

Keywords : kbToolkit kbVBp kbVBp500bug kbVBp600fix kbOSWinCEsearch kbOSWinCE100 kbGrpDSVB
Issue type : kbbug
Technology : kbVBSearch kbAudDeveloper kbWinCETKVBSearch kbWinCESearch kbWinCETK100VB500