最近在網(wǎng)上搜索了一些關(guān)于VB.net實(shí)現(xiàn)關(guān)機(jī)、重啟、注銷的文章，發(fā)現(xiàn)大多介紹的是VB.NET2003用API實(shí)現(xiàn)這些功能，且在XPsp2環(huán)境下無(wú)法正常的關(guān)機(jī)與注銷。而對(duì)于VB.NET2005的介紹幾乎沒(méi)有。本文章所涉及的知識(shí)點(diǎn)有：1、用vb.net實(shí)現(xiàn)關(guān)機(jī)、重啟、注銷功能。
2、通過(guò)使用textbox與timer控件的結(jié)合編寫定時(shí)器功能。
3、為你的程序加上超鏈接。
本篇文章具有一定的基礎(chǔ)性和廣泛的實(shí)用性，相信能夠給VB.net2005初學(xué)者帶來(lái)一定的幫助。
本文所使用的編程環(huán)境是Microsoft Visual Studio 2005，首先打開(kāi) Visual Studio。在文件 (File) 菜單上，單擊新建項(xiàng)目 (New Project)。 在新建項(xiàng)目 (New Project) 對(duì)話框的模板 (Templates) 窗格中，單擊 Windows 應(yīng)用程序 (Windows Application)。單擊確定 (OK)。
具體步驟如下：
1、首先在Form1窗體上添加一個(gè)Label1控件屬性text設(shè)置為:今天:2.然后分別添加3個(gè)button控件name分別為button1、button2、button3它們的text屬性分別為1. 關(guān)閉計(jì)算機(jī)（啟動(dòng)定時(shí)器）2. 注銷3. 重新啟動(dòng)。
圖1
現(xiàn)在我們就需要為程序加上一個(gè)定時(shí)器了，這個(gè)定時(shí)器需要與textbox1控件相關(guān)聯(lián)，輸入正確時(shí)間格式后就可以啟動(dòng)定時(shí)功能了。然后我們需要在窗 體上添加一個(gè)timer、一個(gè)textbox1控件、和一個(gè)RadioButton1控件。讓它們保留默認(rèn)值不變。其中. TextBox1控件的text屬性設(shè)置為：00:00:00 。RadioButton1控件text設(shè)置為：指定時(shí)間關(guān)機(jī)|時(shí)間格式：00小時(shí):00分鐘:00秒如圖2所示：
圖2
以上界面工作基本完成現(xiàn)在需要輸入代碼了。
雙擊窗體進(jìn)入常規(guī)-聲明Public Class Form1 事件中。
CODE：
Imports System.Runtime.InteropServices
Imports Microsoft.VisualBasic
Public Class Form1
ByVal acc As Integer, ByRef phtok As IntPtr) As Boolean
End Function
ByVal name As String, ByRef pluid As Long) As Boolean
End Function
ByVal disall As Boolean, ByRef newst As TokPriv1Luid,
ByVal len As Integer, ByVal prev As IntPtr,
ByVal relen As IntPtr) As Boolean
End Function
ByVal rea As Integer) As Boolean
End Function
Friend Const SE_PRIVILEGE_ENABLED As Integer = &H2
Friend Const TOKEN_QUERY As Integer = &H8
Friend Const TOKEN_ADJUST_PRIVILEGES As Integer = &H20
Friend Const SE_SHUTDOWN_NAME As String = "SeShutdownPrivilege"
Friend Const EWX_LOGOFF As Integer = &H0 '注銷計(jì)算機(jī)
Friend Const EWX_SHUTDOWN As Integer = &H1'關(guān)閉計(jì)算機(jī)
Friend Const EWX_REBOOT As Integer = &H2'重新啟動(dòng)計(jì)算機(jī)
Friend Const EWX_FORCE As Integer = &H4'關(guān)閉所有進(jìn)程，注銷計(jì)算機(jī)
Friend Const EWX_POWEROFF As Integer = &H8
Friend Const EWX_FORCEIFHUNG As Integer = &H10
Private Shared Sub DoExitWin(ByVal flg As Integer)
Dim xc As Boolean '判斷語(yǔ)句
Dim tp As TokPriv1Luid
Dim hproc As IntPtr = GetCurrentProcess()
'調(diào)用進(jìn)程值
Dim htok As IntPtr = IntPtr.Zero
xc = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES Or TOKEN_QUERY, htok)
tp.Count = 1
tp.Luid = 0
tp.Attr = SE_PRIVILEGE_ENABLED
xc = LookupPrivilegeValue(Nothing, SE_SHUTDOWN_NAME, tp.Luid)
xc = AdjustTokenPrivileges(htok, False, tp, 0, IntPtr.Zero, IntPtr.Zero)
xc = ExitWindowsEx(flg, 0)
End Sub
Public Shared Sub Reboot()
DoExitWin((EWX_FORCE Or EWX_REBOOT)) '重新啟動(dòng)計(jì)算機(jī)
End Sub
Public Shared Sub PowerOff()
DoExitWin((EWX_FORCE Or EWX_POWEROFF)) '關(guān)閉計(jì)算機(jī)
End Sub
Public Shared Sub LogoOff()
DoExitWin((EWX_FORCE Or EWX_LOGOFF)) '注銷計(jì)算機(jī)
End Sub
Dim entTime As Object '保存輸入時(shí)間
Dim xianzaiTime As Object '保存實(shí)時(shí)時(shí)間
Dim startTime As Object '保存開(kāi)始定時(shí)時(shí)間
雙擊
注銷button2按鈕輸入code：
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.ClickLogoOff()'注銷計(jì)算機(jī)End Sub
雙擊重新啟動(dòng)按鈕button3，輸入code：
Private Sub Button3_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Button3.Click
Reboot()
End Sub
雙擊關(guān)閉計(jì)算機(jī)按鈕button1，輸入code：
Private Sub Button1_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Button1.Click
startTime = TimeOfDay
If Not IsDate(TextBox1.Text) Then
'用IsData函數(shù)判斷輸入的時(shí)間格式
MsgBox("你所輸入的不是時(shí)間格式,!", , "錯(cuò)誤")
Else
entTime = TimeValue(TextBox1.Text)
End If
Timer1.Enabled = True
'啟動(dòng)定時(shí)器
Me.WindowState = System.Windows.Forms.FormWindowState.Minimized
'最小化窗體
End Sub
如圖3：
圖3
雙擊timer1控件如圖4：
圖4
輸入代碼：
Private Sub Timer1_Tick(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Timer1.Tick
xianzaiTime = TimeOfDay
If RadioButton1.Checked Then
If DateDiff(Microsoft.VisualBasic.DateInterval.Second,
xianzaiTime, entTime) < 0 Then '用DateDiff函數(shù)判斷是否到時(shí)間了
End If
End If
PowerOff() '關(guān)閉計(jì)算機(jī)
End Sub
好了。基本上一個(gè)定時(shí)關(guān)機(jī)程序就完成了，接下來(lái)加一個(gè)超級(jí)鏈接吧！當(dāng)然對(duì)于高手來(lái)說(shuō)可能是廢話，但是對(duì)于新手來(lái)說(shuō)這也是必備的。這個(gè)超級(jí)鏈接當(dāng)然是我們最喜歡的天極網(wǎng)開(kāi)發(fā)頻道了。
先創(chuàng)建一個(gè)Label控件吧，把它托到窗體上，將text屬性設(shè)置為天極網(wǎng)開(kāi)發(fā)頻道如圖5：
圖5
接下來(lái)需要輸入代碼了，雙擊窗體Form1。
進(jìn)入Public Class Form1事件。
代碼：
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA"(ByVal hwngnd As Integer, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Integer) As Integer
如圖6：
圖6
雙擊剛才添加的label屬性text:（天極網(wǎng)開(kāi)發(fā)頻道）中輸入以下代碼：
Private Sub Label3_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles Label3.Click
ShellExecute(0, "open", "http://dev.yesky.com ", CStr(0), CStr(0), 1)
End Sub
End Class
OK！全部搞定，按F5鍵運(yùn)行如圖7所示，選擇相應(yīng)選項(xiàng)后點(diǎn)擊（關(guān)閉計(jì)算機(jī)啟動(dòng)定時(shí)器按鈕）就可以了，現(xiàn)在程序?qū)凑漳闼O(shè)定的時(shí)間而啟動(dòng)關(guān)閉計(jì)算機(jī)選項(xiàng)。
圖7
關(guān)鍵詞：
VB.NET2005定時(shí)關(guān)機(jī)程序
