Transparent Form

SetTrans procedure sets a form transparent depending on your passed value
julst call it like this

settrans frm1.hwnd, 100

VB Code:

Option Explicit
 
Public Const GWL_EXSTYLE As Long = -20
Public Const WS_EX_LAYERED As Long = &H80000
Public Const LWA_ALPHA As Long = &H2
 
Public Declare Function GetWindowLong Lib "user32.dll" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Public Declare Function SetLayeredWindowAttributes Lib "user32.dll" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Public Declare Function SetWindowLong Lib "user32.dll" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Declare Function SetParent Lib "user32.dll" (ByVal hWndChild As Long, ByVal hWndNewParent As Long) As Long
 
Public Sub SetTrans(ByVal OB_Hwnd As Long, ByVal OB_Val As Integer)
    Dim FTransVal As Long
    Dim Attrib As Long
    Attrib = GetWindowLong(OB_Hwnd, GWL_EXSTYLE)
    SetWindowLong OB_Hwnd, GWL_EXSTYLE, Attrib Or WS_EX_LAYERED
    SetLayeredWindowAttributes OB_Hwnd, RGB(0, 0, 0), OB_Val, LWA_ALPHA
    FTransVal = OB_Val
    Exit Sub
End Sub

The reference to SetParent, the On Error Resume Next and the Exit Sub are all redundant + you can put it all on a couple of lines.

lAlpha: 0 is transparent, 255 is solid, anything inbetween is a grade of translucency. This will only work with top level windows on 2000 and above. See http://www.vbforums.com/showthread.php?t=396385 for transparent form, but visible controls.

VB Code:

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
                ByVal hwnd As Long, _
                ByVal nIndex As Long) As Long
 
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
                ByVal hwnd As Long, _
                ByVal nIndex As Long, _
                ByVal dwNewLong As Long) As Long
                
Private Declare Function SetLayeredWindowAttributes Lib "user32" ( _
                ByVal hwnd As Long, _
                ByVal crKey As Long, _
                ByVal bAlpha As Byte, _
                ByVal dwFlags As Long) As Long
 
Private Const GWL_EXSTYLE = (-20)
Private Const WS_EX_LAYERED = &H80000
Private Const LWA_ALPHA = &H2
 
Private Sub SetTrans(ByVal lhWnd As Long, ByVal lAlpha As Byte)
    SetWindowLong lhWnd, GWL_EXSTYLE, GetWindowLong(lhWnd, GWL_EXSTYLE) Or WS_EX_LAYERED
    SetLayeredWindowAttributes lhWnd, 0&, lAlpha, LWA_ALPHA
End Sub

actually that code is just a snipet from my application. those declarations have some other use in mine but i need not to post them i think.

thanks for the comment bush

Quote:

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Originally Posted by bushmobile

The reference to SetParent, the On Error Resume Next and the Exit Sub are all redundant + you can put it all on a couple of lines.

lAlpha: 0 is transparent, 255 is solid, anything inbetween is a grade of translucency. This will only work with top level windows on 2000 and above. See http://www.vbforums.com/showthread.php?t=396385 for transparent form, but visible controls.

VB Code:

Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" ( _
                ByVal hwnd As Long, _
                ByVal nIndex As Long) As Long
 
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" ( _
                ByVal hwnd As Long, _
                ByVal nIndex As Long, _
                ByVal dwNewLong As Long) As Long
                
Private Declare Function SetLayeredWindowAttributes Lib "user32" ( _
                ByVal hwnd As Long, _
                ByVal crKey As Long, _
                ByVal bAlpha As Byte, _
                ByVal dwFlags As Long) As Long
 
Private Const GWL_EXSTYLE = (-20)
Private Const WS_EX_LAYERED = &H80000
Private Const LWA_ALPHA = &H2
 
Private Sub SetTrans(ByVal lhWnd As Long, ByVal lAlpha As Byte)
    SetWindowLong lhWnd, GWL_EXSTYLE, GetWindowLong(lhWnd, GWL_EXSTYLE) Or WS_EX_LAYERED
    SetLayeredWindowAttributes lhWnd, 0&, lAlpha, LWA_ALPHA
End Sub

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i tried your proposed correction but it didnt work coz you forgot to declare the SetLayeredWindowAttributes API. this declaration is needed by that process. this code works really fine now like the first one

VB Code:

Option Explicit
 
Public Const GWL_EXSTYLE As Long = -20
Public Const WS_EX_LAYERED As Long = &H80000
Public Const LWA_ALPHA As Long = &H2
 
Public Declare Function GetWindowLong Lib "user32.dll" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Public Declare Function SetLayeredWindowAttributes Lib "user32.dll" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Public Declare Function SetWindowLong Lib "user32.dll" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
 
Public Sub SetTrans(ByVal OB_Hwnd As Long, ByVal OB_Val As Integer)
    SetWindowLong OB_Hwnd, GWL_EXSTYLE, GetWindowLong(OB_Hwnd, GWL_EXSTYLE) Or WS_EX_LAYERED
    SetLayeredWindowAttributes OB_Hwnd, RGB(0, 0, 0), OB_Val, LWA_ALPHA
End Sub

Quote:

---

Originally Posted by d3gerald

i tried your proposed correction but it didnt work coz you forgot to declare the SetLayeredWindowAttributes API

---

eh? What are you on about? It's there in post #2.

Thanks Man. May i use this in my app?