Search All hWnds Based on Criteria Within The Function

Category:

System/API

Type:

Modules

Difficulty:

Advanced

Author:

Sephectja

Version Compatibility: Visual Basic 6

More information:

With this module, you can Find all handles to a window. The results are returned in an array.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
'Created by Sephectja (Sephectja@hotmail.com) - www.hydrolix.tk 'Use this code in your own programs if you need to but please 'leave the first 6 lines of commentation in the General Declarations ' This is released under the GPL Licence which means you can modify, change ' and do what you want with the code under the condition that all credits must ' stay and be left untouched. The API calls are from the Microsoft Windows API ' ' A copy of the GPL is at http://www.gnu.org/copyleft/gpl.html ' 'Use of FindChildHwnd function: ' FindChildHwnd(RootHwnd, Caption, Classname, TargetArray()) ' RootHwnd = The hWnd you want to start searching from ' Caption = The caption value of the hWnd value (wildcards are allowed) ' Classname = The classname value of the hWnd (Wildcards are allowed) ' TargetArray = The array that all the hWnd values are returned to (this is done for speed) ' 'Use of GetClass function: ' GetClass(hwnd) ' hwnd = the hWnd Identifier you want the classname from ' 'Use of GetCaption function ' GetCaption(hwnd) ' hwnd = the hWnd Identifier you want the caption from Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hWnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hWnd As Long, ByVal lpString As String, ByVal cch As Long) As Long Private Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hWnd As Long) As Long Private Declare Function GetWindow Lib "user32" (ByVal hWnd As Long, ByVal wCmd As Long) As Long ' GetWindow() Constants Const GW_HWNDFIRST = 0 Const GW_HWNDLAST = 1 Const GW_HWNDNEXT = 2 Const GW_HWNDPREV = 3 Const GW_OWNER = 4 Const GW_CHILD = 5 Const GW_MAX = 5

Code:

Public Function GetClass(ByVal hWnd As Long) As String
    Dim CurWindowClassname As String
    CurWindowClassname = String(255, " ")
    Result = GetClassName(hWnd, CurWindowClassname, 255)
    GetClass = Replace(RTrim(CurWindowClassname), Chr(0), "")
End Function

Public Function GetCaption(ByVal hWnd As Long) As String
    Dim CurWindowCaption As String
    Dim CurWindowCaptionLen As Long
    CurWindowCaptionLen = GetWindowTextLength(hWnd) + 1                  'Get how big our buffer needs to be
    CurWindowCaption = String(CurWindowCaptionLen, " ")                                     'Create our buffer
    Result = GetWindowText(hWnd, CurWindowCaption, CurWindowCaptionLen)  'CurWindowCaption = Varible to send to
    GetCaption = Replace(RTrim(CurWindowCaption), Chr(0), "")                         'Cut off any extra spaces and remove chr 0 (Null)
End Function
Public Function FindChildHwnd(ByVal RootHwnd As Long, ByVal Caption As String, ByVal Classname As String, ByRef TargetArray() As Long) As Long
    'Declare varibles
    Dim curHwnd, lngDepth, Finds As Long
    Dim lvlHwnds() As Long
    Dim FindResults() As Long
    lngDepth = 1                            'Depth 0 = RootHwnd (When we get back to this we've looped through all the hwnds!
    ReDim lvlHwnds(0 To lngDepth) As Long   'So we clear the varible and set boundries
    lvlHwnds(0) = RootHwnd                  'The first main hwnd is the RootHwnd
    Finds = 0                               'Reset the Finds counter
    curHwnd = RootHwnd                      'Show the Hwnd we are working on at the moment
    
    'We now need to loop through until we get back to the RootHwnd
    While lngDepth > 0
        If curHwnd > 0 Then             'We need to check the hwnd value to see if the window we are looking for exists
            lngDepth = lngDepth + 1     'and if it does we go to the next level
            If lngDepth > UBound(lvlHwnds) Then     'Since we are going to the next level we need to re-define this array
                ReDim Preserve lvlHwnds(0 To lngDepth) As Long  'for speed we are only going to redefine the array
            End If
            lvlHwnds(lngDepth) = GetWindow(curHwnd, GW_CHILD)   'Get the the first child window of the next level
            curHwnd = lvlHwnds(lngDepth)    'Set the current hwnd to the current depth of windows
        End If
        If curHwnd = 0 Then
            curHwnd = lvlHwnds(lngDepth - 1)    'We need to go up one level since the last level doesnt exist
            If curHwnd = RootHwnd Then          'When we get back to the the starting hwnd (rootHwnd)
                GoTo skipLoop                   'We need to finish the sub
            End If
            lngDepth = lngDepth - 1             'Reduce the depth by one
            lvlHwnds(lngDepth) = GetWindow(curHwnd, GW_HWNDNEXT)    'Get the next window in the list
            curHwnd = lvlHwnds(lngDepth)                            'Change the current hwnd
        End If
        If curHwnd > 0 Then         'We can only have a match if the hwnd is more than 0
            If GetClass(curHwnd) Like Classname And GetCaption(curHwnd) Like Caption Then   'See if our Caption and Classname we chose when calling the function matches with wildcards
                Finds = Finds + 1       'Increase the finds by 1
                ReDim Preserve FindResults(0 To Finds - 1) As Long
                FindResults(Finds - 1) = curHwnd
            End If
        End If
    Wend
skipLoop:
    FindChildHwnd = Finds   'So we return the amount of finds that we where looking for
    ReDim Preserve TargetArray(0 To UBound(FindResults)) As Long
    TargetArray = FindResults   'We need to set the target array (as an array) so people can access our results
    Exit Function               'and exit the function before doing any other errors
errhand:
    Exit Function
End Function