I have a quick question. More for just knowing, I would like to know how to populate a Combobox that has been created through the API. Below is the code that I would use to Create a Form via the API and ComboBox, but how do I add items.
Any help will be appreciated. Thanks.Code:
Option Explicit
Public Declare Function RegisterClass Lib "user32" Alias "RegisterClassA" (Class As WNDCLASS) As Long
Public Declare Function UnregisterClass Lib "user32" Alias "UnregisterClassA" (ByVal lpClassName As String, ByVal hInstance As Long) As Long
Public Declare Function DefWindowProc Lib "user32" Alias "DefWindowProcA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Public Declare Function GetMessage Lib "user32" Alias "GetMessageA" (lpMsg As Msg, ByVal hwnd As Long, ByVal wMsgFilterMin As Long, ByVal wMsgFilterMax As Long) As Long
Public Declare Function TranslateMessage Lib "user32" (lpMsg As Msg) As Long
Public Declare Function DispatchMessage Lib "user32" Alias "DispatchMessageA" (lpMsg As Msg) As Long
Public Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long
Public Declare Function LoadCursor Lib "user32" Alias "LoadCursorA" (ByVal hInstance As Long, ByVal lpCursorName As Any) As Long
Public Declare Function LoadIcon Lib "user32" Alias "LoadIconA" (ByVal hInstance As Long, ByVal lpIconName As String) As Long
Public Declare Function CreateWindowEx Lib "user32" Alias "CreateWindowExA" (ByVal dwExStyle As Long, ByVal lpClassName As String, ByVal lpWindowName As String, ByVal dwStyle As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hWndParent As Long, ByVal hMenu As Long, ByVal hInstance As Long, lpParam As Any) As Long
Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Public Declare Function MessageBox Lib "user32" Alias "MessageBoxA" (ByVal hwnd As Long, ByVal lpText As String, ByVal lpCaption As String, ByVal wType As Long) As Long
Public Declare Sub PostQuitMessage Lib "user32" (ByVal nExitCode As Long)
Public Type WNDCLASS
style As Long
lpfnwndproc As Long
cbClsextra As Long
cbWndExtra2 As Long
hInstance As Long
hIcon As Long
hCursor As Long
hbrBackground As Long
lpszMenuName As String
lpszClassName As String
End Type
Public Type POINTAPI
x As Long
y As Long
End Type
Public Type Msg
hwnd As Long
message As Long
wParam As Long
lParam As Long
time As Long
pt As POINTAPI
End Type
Public Const CS_VREDRAW = &H1
Public Const CS_HREDRAW = &H2
Public Const CW_USEDEFAULT = &H80000000
Public Const ES_MULTILINE = &H4&
Public Const WS_BORDER = &H800000
Public Const WS_CHILD = &H40000000
Public Const WS_OVERLAPPED = &H0&
Public Const WS_CAPTION = &HC00000 ' WS_BORDER Or WS_DLGFRAME
Public Const WS_SYSMENU = &H80000
Public Const WS_THICKFRAME = &H40000
Public Const WS_MINIMIZEBOX = &H20000
Public Const WS_MAXIMIZEBOX = &H10000
Public Const WS_OVERLAPPEDWINDOW = (WS_OVERLAPPED Or WS_CAPTION Or WS_SYSMENU Or WS_THICKFRAME Or WS_MINIMIZEBOX Or WS_MAXIMIZEBOX)
Public Const WS_EX_CLIENTEDGE = &H200&
Public Const COLOR_WINDOW = 5
Public Const WM_DESTROY = &H2
Public Const WM_LBUTTONDOWN = &H201
Public Const WM_LBUTTONUP = &H202
Public Const IDC_ARROW = 32512&
Public Const IDI_APPLICATION = 32512&
Public Const GWL_WNDPROC = (-4)
Public Const SW_SHOWNORMAL = 1
Public Const MB_OK = &H0&
Public Const MB_ICONEXCLAMATION = &H30&
Public Const CBS_DROPDOWN = 3
Public Const gClassName = "MyClassName"
Public Const gAppName = "My Window Caption"
Public gButtonOldProc As Long
Public gHwnd As Long, gButtonHwnd As Long, gEditHwnd As Long
Public gComboHwnd As Long
Public Sub Main()
Dim wMsg As Msg
''Call procedure to register window classname. If false, then exit.
If RegisterWindowClass = False Then Exit Sub
''Create window
If CreateWindows Then
''Loop will exit when WM_QUIT is sent to the window.
Do While GetMessage(wMsg, 0&, 0&, 0&)
''TranslateMessage takes keyboard messages and converts
''them to WM_CHAR for easier processing.
Call TranslateMessage(wMsg)
''Dispatchmessage calls the default window procedure
''to process the window message. (WndProc)
Call DispatchMessage(wMsg)
Loop
End If
Call UnregisterClass(gClassName$, App.hInstance)
End Sub
Public Function RegisterWindowClass() As Boolean
Dim wc As WNDCLASS
''Registers our new window with windows so we
''can use our classname.
wc.style = CS_HREDRAW Or CS_VREDRAW
wc.lpfnwndproc = GetAddress(AddressOf WndProc) ''Address in memory of default window procedure.
wc.hInstance = App.hInstance
wc.hIcon = LoadIcon(0&, IDI_APPLICATION) ''Default application icon
wc.hCursor = LoadCursor(0&, IDC_ARROW) ''Default arrow
wc.hbrBackground = COLOR_WINDOW ''Default a color for window.
wc.lpszClassName = gClassName$
RegisterWindowClass = RegisterClass(wc) <> 0
End Function
Public Function CreateWindows() As Boolean
On Error GoTo ErrorHandler
''Create actual window.
gHwnd& = CreateWindowEx(0&, gClassName$, gAppName$, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 600, 321, 0&, 0&, App.hInstance, ByVal 0&)
''Create button
gOKHwnd& = CreateWindowEx(0&, "Button", "OK", WS_CHILD, 446, 35, 121, 42, gHwnd&, 0&, App.hInstance, 0&)
gButtonHwnd& = CreateWindowEx(0&, "Button", "Button", WS_CHILD, 446, 98, 121, 42, gHwnd&, 0&, App.hInstance, 0&)
gComboHwnd& = CreateWindowEx(0&, "Combobox", "Test", CBS_DROPDOWN Or WS_CHILD, 45, 245, 170, 400, gHwnd&, 0&, App.hInstance, 0&)
''Since windows are hidden, show them. You can use UpdateWindow to
''redraw the client area.
Call ShowWindow(gHwnd&, SW_SHOWNORMAL)
Call ShowWindow(gButtonHwnd&, SW_SHOWNORMAL)
Call ShowWindow(gComboHwnd&, SW_SHOWNORMAL)
''Get the memory address of the default window
''procedure for the button and store it in gButOldProc
''This will be used in ButtonWndProc to call the original
''window procedure for processing.
gButtonOldProc& = GetWindowLong(gButtonHwnd&, GWL_WNDPROC)
''to set the address of the window procedure.
Call SetWindowLong(gButtonHwnd&, GWL_WNDPROC, GetAddress(AddressOf ButtonWndProc))
CreateWindows = (gHwnd& <> 0)
Exit Function
ErrorHandler:
MsgBox "error"
End Function
Public Function WndProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
''This our default window procedure for the window. It will handle all
''of our incoming window messages and we will write code based on the
''window message what the program should do.
Dim strTemp As String
Select Case uMsg&
Case WM_DESTROY:
''Since DefWindowProc doesn't automatically call
''PostQuitMessage (WM_QUIT). We need to do it ourselves.
''You can use DestroyWindow to get rid of the window manually.
Call PostQuitMessage(0&)
End Select
''Let windows call the default window procedure since we're done.
WndProc = DefWindowProc(hwnd&, uMsg&, wParam&, lParam&)
End Function
