前兩天看了Delphi版面精華區(qū)中的“進(jìn)程死亡的自動復(fù)活“一文,覺得作者的思路很不錯,利用api來監(jiān)視進(jìn)程的活動,當(dāng)被銷毀時就自動再創(chuàng)建進(jìn)程。仔細(xì)推敲之后,發(fā)覺其實(shí)用vb也是可以做到的。于是花了半天的時間寫了以下的程序,實(shí)現(xiàn)了使用WaitForSingleObject API來監(jiān)視被創(chuàng)建的進(jìn)程的活動,一旦返回除time out 之外的消息就自動創(chuàng)建新的進(jìn)程。以下為其實(shí)現(xiàn)代碼。在win2000 server + vb 6.0下通過。 Option Explicit
Private RunFile$
Private Const NORMAL_PRIORITY_CLASS = &H20 '如果進(jìn)程位于前臺,則基本值是9;如果在后臺,則優(yōu)先值為7 Private Const INFINITE = &HFFFFFFFF Private Const WAIT_TIMEOUT = &H102& '對象保持未發(fā)出信號的狀態(tài),但等待超時時間已經(jīng)超過 Private Flag As Boolean ‘進(jìn)程活動監(jiān)視標(biāo)志
'說明∶PROCESS_INFORMATION結(jié)構(gòu)由CreateProcess函數(shù)將關(guān)于新建立的進(jìn)程和 '主要線索的信息寫入其中成員變量 Private Type PROCESS_INFORMATION ' hProcess As Long hThread As Long dwProcessId As Long dwThreadId As Long End Type
'說明∶STARTUPINFO結(jié)構(gòu)用在CreateProcess函數(shù)中指定為新進(jìn)程建立的新窗口的主要屬性。這一 '一信息影響由CreateWindows函數(shù)建立的第一個窗口 Private Type STARTUPINFO cb As Long lpReserved As String lpDesktop As String lpTitle As String dwX As Long dwY As Long dwXSize As Long dwYSize As Long dwXCountChars As Long dwYCountChars As Long dwFillAttribute As Long dwFlags As Long wShowWindow As Integer cbReserved2 As Integer lpReserved2 As Long hStdInput As Long hStdOutput As Long hStdError As Long End Type
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long Private Declare Function CreateProcess Lib "kernel32" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, ByVal lpProcessAttributes As Long, ByVal lpThreadAttributes As Long, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, lpEnvironment As Any, ByVal lpCurrentDirectory As String, lpStartupInfo As STARTUPINFO, lpProcessInformation As PROCESS_INFORMATION) As Long Private Declare Function WaitForInputIdle Lib "user32" (ByVal hProcess As Long, ByVal dwMilliseconds As Long) As Long
Private Sub command1_Click() Dim res& Dim sinfo As STARTUPINFO Dim pinfo As PROCESS_INFORMATION sinfo.cb = Len(sinfo) sinfo.lpReserved = vbNullString sinfo.lpDesktop = vbNullString sinfo.lpTitle = vbNullString sinfo.dwFlags = 0 Label1.Caption = "正在啟動程序" Label1.Refresh ' CreateProcess函數(shù),用于創(chuàng)建一個新的進(jìn)程 res = CreateProcess(DemoFile, vbNullString, 0, 0, True, _ NORMAL_PRIORITY_CLASS, ByVal 0&, vbNullString, sinfo, pinfo) If res Then Label1.Caption = "程序正在運(yùn)行中" WaitForTerm pinfo Label1.Caption = "程序已經(jīng)結(jié)束" Else Label1.Caption = "啟動程序時出錯,可能未正確輸入" & Chr(13) & "程序名或程序所在路徑。" End If End Sub
Private Sub WaitForTerm(pinfo As PROCESS_INFORMATION) Dim res& Dim res1& ' 等待指定的進(jìn)程進(jìn)入空閑狀態(tài),,空閑(Idle)指的是進(jìn)程準(zhǔn)備處理一條消息、但目前暫時沒有消息需要處理的一種狀態(tài) Call WaitForInputIdle(pinfo.hProcess, INFINITE) Command1.Enabled = False Command2.Enabled = True Label1.Refresh Do If Flag Then Exit Do '等待發(fā)出信號 res = WaitForSingleObject(pinfo.hProcess, 0) If res <> WAIT_TIMEOUT Then '如果對象發(fā)出了信號 command1_Click Exit Do End If DoEvents Debug.Print res Loop While True Command1.Enabled = True Command2.Enabled = False End Sub
Private Sub Command3_Click() Flag = True End Sub
Private Sub Form_Load() RunFile = InputBox$("請輸入需要運(yùn)行的程序名與路經(jīng)") Flag = False End Sub
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