吉首大学师范学院电话:怎样用VB小程序实现安全关机？怎么用TextBox实现对文本文档的打开和保存？

Private Declare Function ExitWindowsEx Lib "user32" (ByVal uFlags As Integer, ByVal dwReserved As Integer) As Integer

Const EWX_FORCE As Short = 4

Const EWX_LOGOFF As Short = 0

Const EWX_REBOOT As Short = 2

Const EWX_SHUTDOWN As Short = 1

Dim retval As Integer

' 定义Esc按键

Const VK_ESCAPE As Short = &H1Bs

Private Sub Command1_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command1.Click

If Option1.Checked Then

' 注销当前用户

retval = ExitWindowsEx(EWX_FORCE, 0)

ElseIf Option2.Checked Then

' 关闭计算机

retval = ExitWindowsEx(EWX_SHUTDOWN, 0)

ElseIf Option3.Checked Then

' 重新启动

retval = ExitWindowsEx(EWX_REBOOT, 0)

End If

End Sub

Private Sub Command2_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command2.Click

Me.Close()

End Sub

' 按Esc键时，结束应用程序

Private Sub Form1_KeyPress(ByVal eventSender As System.Object, ByVal eventArgs As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress

Dim KeyAscii As Short = Asc(eventArgs.KeyChar)

If KeyAscii = VK_ESCAPE Then

Me.Close()

End If

If KeyAscii = 0 Then

eventArgs.Handled = True

End If

End Sub

常量名
值
说明

EWX_FORCE
4
终止所有进程,包括没有响应的进程,并注销Windows

EWX_REBOOT
2
重新启动系统

EWX_SHUTDOWN
1
关闭系统

EWX_LOGOFF
0
终止所有正在运行的进程,并注销Windows
----------------------------------------------------
新建标准EXE，加入一个TextBox控件，一个公共对话框，两个菜单。

'打开
Private Sub mnuOpen_Click()
CommonDialog1.Filter = "文档文件(*.txt)|*.txt|所有文件(*.*)|*.*"
CommonDialog1.ShowOpen
Open CommonDialog1.FileName For Input As #1
Text1.Text = StrConv(InputB$(LOF(1), 1), vbUnicode)
Close #1
End Sub

'保存
Private Sub mnuSave_Click()
On Error Resume Next
CommonDialog1.Filter ="文档文件(*.txt)|*.txt|所有文件(*.*)|*.*"
CommonDialog1.ShowSave
Open CommonDialog1.FileName For Output As #1
Print #1, Text1.Text
Close 1
End Sub

TextBox只支持打开64K以下的文件，建议最好设置出错处理。