by BioHazardMX (4 Submissions)
Category: Windows API Call/Explanation
Difficulty: Advanced
Date Added: Wed 3rd February 2021
Rating: 
(2 Votes)
This code uses simple API to launch a program or a document but this code also awaits until the process has ended so you can force the user to do something before proceeding (as setup wizards does). The procedure supports command line parameters, a working folder and showing options.
It's so simple and I couldn't find it on this site so I posted it.
Code Returns
The code returns the hInstance of the new process if sucessfull or the error code if something gone wrong.
API DeclarationsPrivate Const INFINITE As Long = &HFFFFFFFF
Private Const SEE_MASK_FLAG_NO_UI As Long = &H400
Private Const SEE_MASK_NOCLOSEPROCESS As Long = &H40
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
lpIDList As Long
lpClass As String
hkeyClass As Long
dwHotKey As Long
hIcon As Long
hProcess As Long
End Type
Private Declare Function WaitForSingleObject Lib "Kernel32.dll" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Private Declare Function GetLastError Lib "Kernel32.dll" () As Long
Private Declare Function ShellExecuteEx Lib "Shell32.dll" (ByRef lpExecInfo As SHELLEXECUTEINFO) As Long
VBcoders'With this code you'll be able to a launch a program or open a document as if you were using the "ShellExecute" function, but your program will await until the opened process has ended (as installers does)
'Code by BioHazardMX
'Add the following code to a module
Private Const INFINITE As Long = &HFFFFFFFF
Private Const SEE_MASK_FLAG_NO_UI As Long = &H400
Private Const SEE_MASK_NOCLOSEPROCESS As Long = &H40
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
lpIDList As Long
lpClass As String
hkeyClass As Long
dwHotKey As Long
hIcon As Long
hProcess As Long
End Type
Private Declare Function WaitForSingleObject Lib "Kernel32.dll" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Private Declare Function GetLastError Lib "Kernel32.dll" () As Long
Private Declare Function ShellExecuteEx Lib "Shell32.dll" (ByRef lpExecInfo As SHELLEXECUTEINFO) As Long
Private Function ShellExecuteWait(ByVal hWnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long)
Dim lReturn As Long, lResult As Long
Dim tExecuteInfo As SHELLEXECUTEINFO
'Fill the SHELLEXECUTEINFO structure
tExecuteInfo.cbSize = Len(tExecuteInfo)
tExecuteInfo.fMask = SEE_MASK_NOCLOSEPROCESS
tExecuteInfo.hWnd = hWnd
tExecuteInfo.lpVerb = lpOperation
tExecuteInfo.lpFile = lpFile
tExecuteInfo.lpParameters = lpParameters
tExecuteInfo.lpDirectory = lpDirectory
tExecuteInfo.nShow = nShowCmd
'Call the API with the specified parameters
lReturn = ShellExecuteEx(tExecuteInfo)
If lReturn = 0 Then lReturn = GetLastError Else lReturn = tExecuteInfo.hInstApp
'If there's a new process wait while it terminates
If tExecuteInfo.hProcess <> 0 Then
lResult = WaitForSingleObject(tExecuteInfo.hProcess, INFINITE)
End If
'Return the ShellExecuteEx return value
ShellExecuteWait = lReturn
End Function
'And the following code to a form. Also, you must add a CommandButton named "Command1"
Private Sub Command1_Click()
'Hide the window
WindowState = vbMinimized
'Execute the Notepad and wait for termination
Call ShellExecuteWait(hWnd, "open", "C:\Windows\Notepad.exe", "", "", vbNormalFocus)
'Show the window
WindowState = vbNormal
End Sub
