Hwnd?

Is there anyway to get a programs hwnd just by knowing its file path and extension (Ex: C:\Windows\Calc.exe)? I dought there is, but I'm just wondering.

[Serge]

Window Handle (hWnd) is being assign by windows when you run the program. So, if the program is not running, then it won't have any hWnd.

Well, say if i wanted to get the running tasks..which I know how to do, how could i tell what their handles are? Like when i get the running tasks, it only returns their file path. Anyway to determine it then?

[kedaman]

You can get the running exe file from the wnd, i have the code it you're looking for it

[Serge]

Here is how to get running processes:

Module Code

Public Declare Function Process32First Lib "kernel32" (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Public Declare Function Process32Next Lib "kernel32" (ByVal hSnapshot As Long, lppe As PROCESSENTRY32) As Long
Public Declare Function CloseHandle Lib "Kernel32.dll" (ByVal Handle As Long) As Long
Public Declare Function OpenProcess Lib "Kernel32.dll" (ByVal dwDesiredAccessas As Long, ByVal bInheritHandle As Long, ByVal dwProcId As Long) As Long
Public Declare Function EnumProcesses Lib "psapi.dll" (ByRef lpidProcess As Long, ByVal cb As Long, ByRef cbNeeded As Long) As Long
Public Declare Function GetModuleFileNameExA Lib "psapi.dll" (ByVal hProcess As Long, ByVal hModule As Long, ByVal ModuleName As String, ByVal nSize As Long) As Long
Public Declare Function EnumProcessModules Lib "psapi.dll" (ByVal hProcess As Long, ByRef lphModule As Long, ByVal cb As Long, ByRef cbNeeded As Long) As Long
Public Declare Function CreateToolhelp32Snapshot Lib "kernel32" (ByVal dwFlags As Long, ByVal th32ProcessID As Long) As Long
Public Declare Function GetVersionExA Lib "kernel32" (lpVersionInformation As OSVERSIONINFO) As Long
Public Type PROCESSENTRY32
    dwSize As Long
    cntUsage As Long
    th32ProcessID As Long           ' This process
    th32DefaultHeapID As Long
    th32ModuleID As Long            ' Associated exe
    cntThreads As Long
    th32ParentProcessID As Long     ' This process's parent process
    pcPriClassBase As Long          ' Base priority of process threads
    dwFlags As Long
    szExeFile As String * 260       ' MAX_PATH
End Type
Public Type OSVERSIONINFO
    dwOSVersionInfoSize As Long
    dwMajorVersion As Long
    dwMinorVersion As Long
    dwBuildNumber As Long
    dwPlatformId As Long           '1 = Windows 95, 2 = Windows NT
    szCSDVersion As String * 128
End Type
Public Const PROCESS_QUERY_INFORMATION = 1024
Public Const PROCESS_VM_READ = 16
Public Const MAX_PATH = 260
Public Const STANDARD_RIGHTS_REQUIRED = &HF0000
Public Const SYNCHRONIZE = &H100000
'STANDARD_RIGHTS_REQUIRED Or SYNCHRONIZE Or &HFFF
Public Const PROCESS_ALL_ACCESS = &H1F0FFF
Public Const TH32CS_SNAPPROCESS = &H2&
Public Const hNull = 0
Public Function GetRunningProcesses() As Variant
    Dim arrProc()
    Dim intIndex As Integer
    Dim lRet As Long
    
    Select Case getVersion()
        Case 1 'Windows 95/98
            Dim strProcess As String
            Dim hSnap As Long, udtProc As PROCESSENTRY32
        
            hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
            If hSnap = hNull Then Exit Function
            udtProc.dwSize = Len(udtProc)
            ' Iterate through the processes
            lRet = Process32First(hSnap, udtProc)
            Do While lRet
                strProcess = StripNulls(udtProc.szExeFile)
                ReDim Preserve arrProc(intIndex)
                arrProc(intIndex) = strProcess
                intIndex = intIndex + 1
                lRet = Process32Next(hSnap, udtProc)
            Loop
        Case 2 'Windows NT
            Dim lcb As Long, lcbNeeded As Long, lNumElements As Long
            Dim lProcessIDs() As Long, lcbNeeded2 As Long
            Dim lModules(1 To 200) As Long
            Dim strModuleName As String
            Dim lSize As Long, lhProcess As Long, i As Long
            
            'Get the array containing the process id's for each process object
            lcb = 8
            lcbNeeded = 96
            Do While lcb <= lcbNeeded
                lcb = lcb * 2
                ReDim lProcessIDs(lcb / 4) As Long
                lRet = EnumProcesses(lProcessIDs(1), lcb, lcbNeeded)
            Loop
            lNumElements = lcbNeeded / 4
            For i = 1 To lNumElements
                'Get a handle to the Process
                lhProcess = OpenProcess(PROCESS_QUERY_INFORMATION _
                Or PROCESS_VM_READ, 0, lProcessIDs(i))
                'Got a Process handle
                If lhProcess <> 0 Then
                    'Get an array of the module handles for the specified
                    'process
                    lRet = EnumProcessModules(lhProcess, lModules(1), 200, _
                    lcbNeeded2)
                    'If the Module Array is retrieved, Get the ModuleFileName
                    If lRet <> 0 Then
                        strModuleName = Space(MAX_PATH)
                        lSize = 500
                        lRet = GetModuleFileNameExA(lhProcess, lModules(1), _
                        strModuleName, lSize)
                        ReDim Preserve arrProc(intIndex)
                        arrProc(intIndex) = Left(strModuleName, lRet)
                        intIndex = intIndex + 1
                    End If
                End If
                'Close the handle to the process
                lRet = CloseHandle(lhProcess)
            Next
    End Select
    GetRunningProcesses = arrProc
End Function


Function StripNulls(pstrString As String) As String
         StripNulls = Left(pstrString, InStr(pstrString, vbNullChar) - 1)
End Function

Public Function getVersion() As Long
    Dim udtOSVersion As OSVERSIONINFO
    Dim lRet As Integer
    
    udtOSVersion.dwOSVersionInfoSize = 148
    udtOSVersion.szCSDVersion = Space$(128)
    lRet = GetVersionExA(udtOSVersion)
    getVersion = udtOSVersion.dwPlatformId
End Function

Form Code (Requires Listbox - List1 and Commandb button - Command1)

Private Sub Command1_Click()
    Dim i As Integer
    Dim arrProc()
    
    List1.Clear
    arrProc = GetRunningProcesses
    For i = 0 To UBound(arrProc)
        List1.AddItem arrProc(i)
    Next
End Sub

Ok Kedaman, post it up...I'll take it. Serge, I know how to get the running processes..but I guess there's no way to determine the hwnd by knowing the file path. But I am still interested in Kedaman's code. Thanks all anyway.

[kedaman]

OK, here comes the code:

'Get active window caption
Public Declare Function GetForegroundWindow Lib "user32" () As Long
Public Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long

'Get active window exe
Public Const TH32CS_SNAPPROCESS As Long = 2&
Public Const MAX_PATH As Long = 260
Public Type PROCESSENTRY32
dwSize As Long
cntUsage As Long
th32ProcessID As Long
th32DefaultHeapID As Long
th32ModuleID As Long
cntThreads As Long
th32ParentProcessID As Long
pcPriClassBase As Long
dwflags As Long
szexeFile As String * MAX_PATH
End Type
Public Declare Function GetWindowThreadProcessId Lib "user32" (ByVal hwnd As Long, lpdwProcessId As Long) As Long
Public Declare Function CreateToolhelpSnapshot Lib "Kernel32" Alias "CreateToolhelp32Snapshot" (ByVal lFlgas As Long, ByVal lProcessID As Long) As Long
Public Declare Function ProcessFirst Lib "Kernel32" Alias "Process32First" (ByVal hSnapshot As Long, uProcess As PROCESSENTRY32) As Long
Public Declare Function ProcessNext Lib "Kernel32" Alias "Process32Next" (ByVal hSnapshot As Long, uProcess As PROCESSENTRY32) As Long
Public Declare Sub CloseHandle Lib "Kernel32" (ByVal hPass As Long)

'Get active window caption
Public Function GetWindowCaption(ByVal hwnd As Long, ByVal lParam As Long) As String
    Dim lWin As Long
    Dim strWinText As String
    strWinText = Space(255)
    lWin = GetWindowText(hwnd, strWinText, Len(strWinText))
    If lWin Then strWinText = Left(strWinText, lWin)
    GetWindowCaption = strWinText
End Function

'Get active window exe
Public Function GetExeFromHandle(hwnd As Long) As String
    Dim threadID As Long, processID As Long, hSnapshot As Long
    Dim uProcess As PROCESSENTRY32, rProcessFound As Long
    Dim i As Integer, szExename As String
    ' Get ID for window thread
    threadID = GetWindowThreadProcessId(hwnd, processID)
    ' Check if valid
    If threadID = 0 Or processID = 0 Then Exit Function
    ' Create snapshot of current processes
    hSnapshot = CreateToolhelpSnapshot(TH32CS_SNAPPROCESS, 0&)
    ' Check if snapshot is valid
    If hSnapshot = -1 Then Exit Function
    'Initialize uProcess with correct size
    uProcess.dwSize = Len(uProcess)
    'Start looping through processes
    rProcessFound = ProcessFirst(hSnapshot, uProcess)
    Do While rProcessFound
        If uProcess.th32ProcessID = processID Then
            'Found it, now get name of exefile
            i = InStr(1, uProcess.szexeFile, Chr(0))
            If i > 0 Then szExename = Left$(uProcess.szexeFile, i - 1)
            Exit Do
        Else
            'Wrong ID, so continue looping
            rProcessFound = ProcessNext(hSnapshot, uProcess)
        End If
    Loop
    Call CloseHandle(hSnapshot)
    GetExeFromHandle = szExename
End Function

And to use it:

GetExeFromHandle mywnd&