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

• 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

Check for the error immediately following the LineInputString or InputFields method and handle it accordingly. See the MORE INFORMATION section below for details.

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

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

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

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

3. Set the Text1.Multiline property to True.

4. 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
   
   

5. 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