运行以下代码时：
Public Class Form4
'Public LAST_USER As String = "last user: uidxxxxx"
Friend WithEvents LastUser As System.Windows.Forms.TextBox
Private Sub checkFile()
If File.Exists("D:\Tebenator\userid.txt") = False Then
Try
File.Create("D:\Tebenator\userid.txt")
' Info()
Catch ex As Exception
MsgBox("Exception:" + ex.ToString)
End Try
Else
Info()
End If
End Sub
Private Sub Info()
Dim line As String
Dim objReader As New System.IO.StreamReader("D:\Tebenator\userid.txt")
Do While objReader.Peek() <> -1
line = objReader.ReadLine
If (String.IsNullOrEmpty(line.ToString)) Then
TextBox1.Text = " Last session info:" & Environment.NewLine +
"-Last user : uidxxxxx" & Environment.NewLine +
"-Session closed: (manual or automatically at xx:xx (local)"
Exit Do
Else
If (line.StartsWith("last_user")) Then
Dim a() As String
a = Split(line, "uid")
If (String.IsNullOrWhiteSpace(a.ToString)) Then
TextBox1.Text = " Last session info:" & Environment.NewLine +
"-Last user : uidxxxxx" & Environment.NewLine +
"-Session closed: (manual or automatically at xx:xx (local)"
Else
For i As Integer = 0 To a.Length - 1
Dim info As System.IO.FileInfo
info = My.Computer.FileSystem.GetFileInfo("D:\Tebenator\userid.txt")
TextBox1.Text = " Last session info:" & Environment.NewLine +
"-Last user :uid" + a(i) & Environment.NewLine +
"-Session closed: (manual or automatically on " + info.LastWriteTime + ")"
Next
End If
End If
End If
Loop
objReader.Close()
End Sub
Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'checkFile()
Projects.Items.Add("A")
Projects.Items.Add("B")
Projects.Items.Add("C")
End Sub
Private Sub PictureBoxLogo_Click(sender As Object, e As EventArgs) Handles PictureBoxLogo.Click
Dim path As String
path = System.IO.Path.GetDirectoryName( _
System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase)
'System.Diagnostics.Process.Start(path & "\kill tebenator.exe")
End Sub
Private Sub LinkLabelMapDrives_LinkClicked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.LinkLabelLinkClickedEventArgs) Handles LinkLabelMapDrives.LinkClicked
Form2.Show()
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Button1.FlatAppearance.BorderColor = Color.Orange
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Button2.FlatAppearance.BorderColor = Color.Orange
If MessageBox.Show("Confirm SHUT DOWN action?", "Tebenator Demon: Shutting down ..", MessageBoxButtons.YesNo) = Windows.Forms.DialogResult.Yes Then
Me.Close()
End If
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
Button3.FlatAppearance.BorderColor = Color.Orange
Form3.Show()
End Sub
Private Sub ButtonStartSession_Click(sender As Object, e As EventArgs) Handles ButtonStartSession.Click
Dim Path1 As String
Path1 = "D:\users\Popa Andrei\project\Prj_A"
Dim Path2 As String
Path2 = "D:\users\Popa Andrei\project\Prj_B"
Dim Path3 As String
Path3 = "D:\users\Popa Andrei\project\Prj_C"
Dim id As Integer
id = Convert.ToInt32(TextBoxUid.Text)
If (id > 9999) Then
MessageBox.Show("Uid too long,please modify.", "Error!", MessageBoxButtons.OK)
ElseIf (id < 1000) Then
MessageBox.Show("Uid too short,pleaste modify.", "Error!", MessageBoxButtons.OK)
Else
Dim SelectedItem As Object
SelectedItem = Projects.SelectedItem
If (SelectedItem.ToString() Is "A") Then
Dim Folder As String = My.Computer.FileSystem.SpecialDirectories.Desktop + " \Dir_Project_" + SelectedItem.ToString
If Directory.Exists(Folder) = False Then
Try
Directory.CreateDirectory(Folder)
Catch ex As Exception
End Try
End If
For Each _File As String In Directory.GetFiles(Folder)
File.Delete(_File)
Next
My.Computer.FileSystem.CopyDirectory(Path1, Folder.ToString, True)
Process.Start(Folder)
End If
If (SelectedItem.ToString() Is "B") Then
Dim Folder As String = My.Computer.FileSystem.SpecialDirectories.Desktop + " \Dir_Project_" + SelectedItem.ToString
If Directory.Exists(Folder) = False Then
Try
Directory.CreateDirectory(Folder)
Catch ex As Exception
End Try
End If
For Each _File As String In Directory.GetFiles(Folder)
File.Delete(_File)
Next
My.Computer.FileSystem.CopyDirectory(Path2, Folder.ToString, True)
Process.Start(Folder)
End If
If (SelectedItem.ToString() Is "C") Then
Dim Folder As String = My.Computer.FileSystem.SpecialDirectories.Desktop + " \Dir_Project_" + SelectedItem.ToString
If Directory.Exists(Folder) = False Then
Try
Directory.CreateDirectory(Folder)
Catch ex As Exception
End Try
End If
For Each _File As String In Directory.GetFiles(Folder)
File.Delete(_File)
Next
My.Computer.FileSystem.CopyDirectory(Path3, Folder.ToString, True)
Process.Start(Folder)
End If
Dim File_Name As String = "D:\Tebenator\userid.txt"
Try
If File.Exists(File_Name) Then
Dim objWriter As New System.IO.StreamWriter(File_Name, True)
objWriter.Write("last_user=uid" + TextBoxUid.Text)
objWriter.Close()
End If
Catch ex As Exception
MsgBox("Exception:" + ex.ToString)
End Try
End If
End Sub
Public Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
checkFile()
End Sub
End Class
表单正确加载，我键入uid值然后选择项目，但是当我单击Start Session时，我在第168行得到以下错误（Dim objWriter As New System.IO.StreamWriter（File_Name，True））：< / p>
类型＆＃39; System.IO.IOException＆＃39;的第一次机会异常发生在mscorlib.dll
答案 0 :(得分：0)
正确的方法是修改checkFile方法，如下所示：
Private Sub checkFile()
If File.Exists("D:\Tebenator\userid.txt") = False Then
Try
Dim f As FileStream = File.Create("D:\Tebenator\userid.txt")
f.Close()
Catch ex As Exception
MsgBox("Exception:" + ex.ToString)
End Try
Else
End If
End Sub