VB.net没有执行sub中的所有代码？

Question

这是一个奇怪的错误，我不认为它与我的代码有任何关系，因为它发生在我的程序的几个部分。我在Visual Studio 2010中，在VB.net开发设置中工作，程序只执行部分代码。

我在加载表单时调用函数GenerateBarcode。下面是函数GenerateBarcode：

'Generate random barcode
    Dim i As Integer
    Dim BarcodeIntegerStore(10) As Integer
    Dim Barcode As String

重新启动：

    'Generate the 10 integers of the barcode
    'Form "BB" & 10 x integers
    For i = 1 To 10
        'Find a random number between 0 and 9
        BarcodeIntegerStore(i) = CInt(Math.Ceiling(Rnd() * 9))
        'Barcode is cumulative and so gains in size with each i value
        Barcode = Barcode & Str(BarcodeIntegerStore(i))
    Next

    'Remove all spaces from barcode
    Barcode = Barcode.Replace(" ", "")
    'Add the BB at the start
    Barcode = "BB" & Barcode

    'Check barcode isn't already in use
    Dim UserToSearch As New User

    'Open the Users file
    FileOpen(1, UserFileName, OpenMode.Random, OpenAccess.Read, OpenShare.Default, Len(UserToSearch))

    For i = 1 To (LOF(1) \ Len(UserToSearch))
        'Get the record
        FileGet(1, UserToSearch, i)
        'Check it already isn't in use
        If txt_UserBarcode.Text = UserToSearch.UserBarcode Then
            GoTo Restart
        End If
    Next

    'Populate the barcode textbox
    txt_UserBarcode.Text = Barcode

    FileClose(1)

代码在FileOpen(1, UserFileName, OpenMode.Random, OpenAccess.Read, OpenShare.Default, Len(UserToSearch))停止执行，这是一个问题，因为我有代码要在表单加载时执行te函数调用。