vb.net如何判断shell完成，或者等待shell完成

    Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long    Private Declare Function GetExitCodeProcess Lib "kernel32" (ByVal hProcess As Long, lpExitCode As Long) As Long    Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long    Const PROCESS_QUERY_INFORMATION = &H400    Const STILL_ALIVE = &H103    Private Sub Command1_Click()        Dim pid As Long        pid = Shell("c:/a.bat", vbNormalFocus)        hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid)        Do            Call GetExitCodeProcess(hProcess, ExitCode)            DoEvents()        Loop While ExitCode = STILL_ALIVE        Call CloseHandle(hProcess)        MsgBox("运行结束")    End Sub

VB启动/结束另一程序(Shell 等待程序运行结束)
 
    VB 中，常以Shell指令来执行外部程式，然而它在Create该外部process 後，立刻就会回到vb 的下一行程式，无法做到等待该Process结束时，才执行下一行指令，或是说，无法得知该Process是否已结束，甚者，该Process执行到一半，又该如何中止其执行等等，这些都不是Shell指令所能控制的，因此我们需使API的帮助来完成。 

    第一个问题，如何等待shell所Create的process结束後才往後执行vb的程式。首先要知道的是，每个Process有唯一的一个ProcessID，这是OS给定的，用来区别每个 Process，这个Process ID(PID)主要可用来取得该Process相对应的一些资讯，然而要对该Process的控制，却大多透过 Process Handle(hProcess)。

    VB Shell指令的传回值是PID，而非hProcess，所以我们需透过OpenProcess这个API来取得 hProcess而OpenProcess()的第一个叁数，指的是所取得的hProcess所具有的能力，像 PROCESS_QUERY_INFORMATION 便是让GetExitCode()可取得hProcess所指的process之状态，而PROCESS_TERMINATE，便是让TerminateProcess(hProcess..)的指令能够生效，也就是说，不同叁数设定，使hProcess所具有的权限、能力有所不同。

    取得 hProcess後便可以使用WaitForSingleObject()来等待hProcess状态的改变，也就是说，它会等待 hProcess所指的process执行完，这个指令才结束，它第二个叁数所指的是 WaitForSingleObject()所要等待的时间(in milliseconds )，如果超过所指的时间，就TimeOut而结束WaitForSingleObject()的等待。若要它无限的等下去，就设定为INFIN99vE。

pid = Shell("C:/tools/spe3/pe2.exe", vbNormalFocus) hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid) ExitEvent = WaitForSingleObject(hProcess, INFIN99vE) Call CloseHandle(hProcess)  

上例会无限等待shell指令create之process结束後，才再做後面的vb指令。有时觉得那会等太久，所以有第二个解决方式：

     等process结束时再通知vb 就好，即：设定一个公用变数(isDone)，当它变成True时代表Shell所Create的Process已结束。

    当Process还在执行时，GetExitCodeProcess会传&H103给其第二个叁数，直到结束时才传另外的数值，如果程式正常结束，那Exitcode = 0，否则就得看它如何结束了。

     或许有人在其他地方看到 loop的地方是Loop while Exitcode ＜＞ 0，那有一点危险，如果以这程子来看，您不是用F4来离开pe2而是用右上方 X 的结束dos window那麽，会因为ExitCode的值永远不会是0，而进入无穷的回圈。 

    Dim pid As Long    pid = Shell("C:/tools/spe3/pe2.exe", vbNormalFocus)     hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid)     isDone = False     Do         Call GetExitCodeProcess(hProcess, ExitCode)         Debug.Print ExitCode         DoEvents     Loop While ExitCode = STILL_ALIVE     Call CloseHandle(hProcess)     isDone = True 

另外，如果您的shell所Create的程式，有视窗且为立刻Focus者，可另外用以下的方式：

    Dim pid As Long    Dim hwnd5 As Long    pid = Shell("c:/tools/spe3/pe2.exe", vbNormalFocus)     hwnd5 = GetForegroundWindow()     isDone = False     Do While IsWindow(hwnd5)         DoEvents     Loop     isDone = True 

而如何强迫shell所Create的process结束呢，那便是 

    Dim aa As Long    If hProcess <> 0 Then         aa = TerminateProcess(hProcess, 3838)     End If 

hProcess便是先前的例子中所取得的那个Process Handle， 3838所指的是传给GetExitCodeProcess()中的第二叁数，这是我们任意给的，但最好不要是0，因为0一般是代表正常结束，当然这样设也不会有错。当然不可设&H103，以这个例子来看，如果程式正处於以下的LOOP 

    Do         Call GetExitCodeProcess(hProcess, ExitCode)         Debug.Print ExitCode         DoEvents     Loop While ExitCode = STILL_ALIVE     Debug.print ExitCode 

    而执行了 TerminateProcess(hProcess, 3838)那会看到ExitCode = 3838。

    然而，这个方式在win95没问题，在NT中，可能您要在OpenProcess()的第一个叁数要更改成 PROCESS_QUERY_INFORMATION Or PROCESS_TERMINATE 这样才能Work。不过良心的建议，非到最後关头，不要使用TerminateProcess()，因不正常的结束，往往许多程式结束前所要做的事都没有做，可能造成Resource的浪费，甚者，下次再执行某些程式时会有问题，例如：本人常使用MS-dos Shell Link 的方式执行一程式，透过Com port与大电脑的联结，如果Ms-dos Shell Link 不正常结束，下次再想Link时，会发现too Many Opens，这便是一例。 


另外，有人使用Shell来执行.bat档，即：

    pid = Shell("c:/aa.bat", vbNormalFocus)

   可是却遇上aa.bat结束了，但ms-dos的Window却仍活着，那可以用以下的方式来做

       pid = Shell("c:/command.com /c c:/aa.bat", vbNormalFocus) 

    那是执行Command.com，而Command.com指定执行c:/aa.bat 而且结束时自动Close，所有程式如下：

    Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long    Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long    Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long    Private Declare Function GetExitCodeProcess Lib "kernel32" (ByVal hProcess As Long, lpExitCode As Long) As Long    Private Declare Function TerminateProcess Lib "kernel32" (ByVal hProcess As Long, ByVal uExitCode As Long) As Long    Private Declare Function GetForegroundWindow Lib "user32" () As Long    Private Declare Function IsWindow Lib "user32" (ByVal hwnd As Long) As Long    Const PROCESS_QUERY_INFORMATION = &H400    Const STILL_ALIVE = &H103    Const INFIN99vE = &HFFFF    Private ExitCode As Long    Private hProcess As Long    Private isDone As Long    Private Sub Command1_Click()        Dim pid As Long        pid = Shell("C:/tools/spe/pe2.exe", vbNormalFocus)        hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid)        isDone = False        Do            Call GetExitCodeProcess(hProcess, ExitCode)            Debug.Print ExitCode            DoEvents()        Loop While ExitCode = STILL_ALIVE        Call CloseHandle(hProcess)        isDone = True    End Sub    Private Sub Command2_Click()        Dim pid As Long        Dim ExitEvent As Long        pid = Shell("C:/tools/spe3/pe2.exe", vbNormalFocus)        hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, 0, pid)        ExitEvent = WaitForSingleObject(hProcess, INFIN99vE)        Call CloseHandle(hProcess)    End Sub    Private Sub Command3_Click()        Dim aa As Long        If hProcess <> 0 Then            aa = TerminateProcess(hProcess, 3838)        End If    End Sub    Private Sub Command4_Click()        Dim pid As Long        Dim hwnd5 As Long        pid = Shell("c:/tools/spe3/pe2.exe", vbNormalFocus)        hwnd5 = GetForegroundWindow()        isDone = False        Do While IsWindow(hwnd5)            DoEvents()        Loop        isDone = True    End Sub    Private Sub Command5_Click()        Dim pid As Long        'pid = Shell("c:/windows/command/xcopy c:/aa.bat a:", vbHide)         pid = Shell("c:/command.com /c c:/aa.bat", vbNormalFocus)    End Sub

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在使用shell后,如何等待此程序完成后,程序才继续执行.我们使用 shell 调用一个外部程序的时候,通常 vb(a) 会在调用之后继续下面的语句,而不管此 shell 程序执行完成没有.有时我们需要在此 shell 执行完成之后才继续,又当如何呢?请看源程:

    Public Declare Function OpenProcess Lib "kernel32" Alias "OpenProcess" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long    Public Declare Function WaitForSingleObject Lib "kernel32" Alias "WaitForSingleObject" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long    Public Declare Function CloseHandle Lib "kernel32" Alias "CloseHandle" (ByVal hObject As Long) As Long    Dim lngPId As Long    Dim lngPHandle As Long    lngPId = Shell("Notepad", vbNormalFocus)    lngPHandle = OpenProcess(SYNCHRONIZE, 0, lngpId)    If lngPHandle <> 0 Then         Call WaitForSingleObject(lngPHandle, INFINITE) ' 无限等待， 直到程式结束        Call CloseHandle(lngPHandle)     End If

需要注意的是,在 shell 程序未完成前,你的程序不能做任何事,请小心为之。

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    Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long    Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long    Private Declare Function ShellExecuteEx Lib "shell32.dll" Alias "ShellExecuteExA" (lpInfo As Any) As Long    Private Type SHELLEXECUTEINFO        cbSize  As Long        fMask  As Long        hwnd  As Long        lpVerb  As String        lpFile  As String        lpParameters  As String        lpDirectory  As String        nShow  As Long        hInstApp  As Long       'Optional  members        lpIDList  As Long        lpClass    As String        hkeyClass  As Long        dwHotKey  As Long        hIcon_OR_Monitor  As Long        hProcess  As Long    End Type    Private Sub Form_Load()        Dim si As SHELLEXECUTEINFO        si.cbSize = Len(si)        si.lpVerb = "open"        si.lpFile = "notepad.exe"        si.lpParameters = ""        si.lpDirectory = ""        si.nShow = 5            'SW_SHOW        si.fMask = &H40      'SEE_MASK_NOCLOSEPROCESS        ShellExecuteEx si        If si.hProcess <> 0 Then            WaitForSingleObject(si.hProcess, &HFFFFFFFF)      '  无限等待，  直到程式结束            CloseHandle si.hProcess            MsgBox "程序运行完毕！"        End If    End Sub

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shell命令一观：

shell "cmd /c dir",1'/c表示执行完即关闭窗口 
shell "cmd /k dir",1'/k表示执行完停留 
shell "cmd /c dir && pause",1'多条语句可用&&连接 


关于cmd的具体用法可以在命令提示符下敲入cmd/?看看太多了，只列举一些典型的： 
CMD [/A | /U] [/Q] [/D] [/E:ON | /E:OFF] [/F:ON | /F:OFF] [/V:ON | /V:OFF] [[/S] [/C | /K] string] 


/C         执行字符串指定的命令然后终断 
/K         执行字符串指定的命令但保留 
/S        在 /C 或 /K 后修改字符串处理(见下) 
/Q          关闭回应 
/D        从注册表中停用执行 AutoRun 命令(见下) 
/A         使向内部管道或文件命令的输出成为 ANSI 
/U          使向内部管道或文件命令的输出成为 Unicode 
/T:fg      设置前景/背景颜色(详细信息，请见 COLOR /?) 
/E:ON   启用命令扩展(见下) 
/E:OFF  停用命令扩展(见下) 
/F:ON   启用文件和目录名称完成字符 (见下) 
/F:OFF  停用文件和目录名称完成字符(见下) 
/V:ON   将 ! 作为定界符启动延缓环境变量扩展。

              如: /V:ON 会允许 !var! 在执行时允许 !var! 扩展变量 var。var 语法在输入时扩展变量，这与在一个 FOR 循环内不同。 
/V:OFF  停用延缓的环境扩展。