Option Explicit
'Declaraciones de los diferentes tipos de regiones a crear
Private Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CreateEllipticRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CreateRoundRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long, ByVal X3 As Long, ByVal Y3 As Long) As Long
Private Declare Function CreatePolygonRgn Lib "gdi32" (lpPoint As POINTAPI, ByVal nCount As Long, ByVal nPolyFillMode As Long) As Long
'POINTAPI tipo requerido para CreatePolygonRgn
Private Type POINTAPI
X As Long
Y As Long
End Type
'Fija la region
Private Declare Function SetWindowRgn Lib "user32" (ByVal hwnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
'Combina la region
Private Declare Function CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
'Tipo de combinacion
Const RGN_XOR = 3
'----------------------------------------------------------------------------------------------------
Public Sub MakeTransparent(TransForm As Form)
Dim ErrorTest As Double
'en caso de que haya un error, se ignora
On Error Resume Next
Dim Regn As Long
Dim TmpRegn As Long
Dim TmpControl As Control
Dim LinePoints(4) As POINTAPI
'Puesto que las API trabajan en pixels, cambiamos el modo de escala a pixels
TransForm.ScaleMode = 3
'Debe ejecutarse sobre un formulario son bordes.
If TransForm.BorderStyle <> 0 Then MsgBox "Cambia el borderstyle a 0!", vbCritical, "ACK!": End
'Hace todo invisible
Regn = CreateRectRgn(0, 0, 0, 0)
'Un bucle para controlar cada control en el formulario
For Each TmpControl In TransForm
'Si el control es una linea...
If TypeOf TmpControl Is Line Then
'Comprueba la inclinacion
If Abs((TmpControl.Y1 - TmpControl.Y2) / (TmpControl.X1 - TmpControl.X2)) > 1 Then
'Si es mas vertical que horizontal entonces..
'Fija los puntos
LinePoints(0).X = TmpControl.X1 - 1
LinePoints(0).Y = TmpControl.Y1
LinePoints(1).X = TmpControl.X2 - 1
LinePoints(1).Y = TmpControl.Y2
LinePoints(2).X = TmpControl.X2 + 1
LinePoints(2).Y = TmpControl.Y2
LinePoints(3).X = TmpControl.X1 + 1
LinePoints(3).Y = TmpControl.Y1
Else
'Si es mas horizontal que vertical, entonces...
'Fija los puntos
LinePoints(0).X = TmpControl.X1
LinePoints(0).Y = TmpControl.Y1 - 1
LinePoints(1).X = TmpControl.X2
LinePoints(1).Y = TmpControl.Y2 - 1
LinePoints(2).X = TmpControl.X2
LinePoints(2).Y = TmpControl.Y2 + 1
LinePoints(3).X = TmpControl.X1
LinePoints(3).Y = TmpControl.Y1 + 1
End If
'Crea el nuevo poligono con los puntos
TmpRegn = CreatePolygonRgn(LinePoints(0), 4, 1)
'Si el control es una figura...
ElseIf TypeOf TmpControl Is Shape Then
'si es asi, comprobamos el tipo
If TmpControl.Shape = 0 Then
'Es un rectangulo
TmpRegn = CreateRectRgn(TmpControl.Left, TmpControl.Top, TmpControl.Left + TmpControl.Width, TmpControl.Top + TmpControl.Height)
ElseIf TmpControl.Shape = 1 Then
'Es un cuadrado
If TmpControl.Width < TmpControl.Height Then
TmpRegn = CreateRectRgn(TmpControl.Left, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2, TmpControl.Left + TmpControl.Width, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width)
Else
TmpRegn = CreateRectRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2, TmpControl.Top, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height, TmpControl.Top + TmpControl.Height)
End If
ElseIf TmpControl.Shape = 2 Then
'Es un ovalo
TmpRegn = CreateEllipticRgn(TmpControl.Left, TmpControl.Top, TmpControl.Left + TmpControl.Width + 0.5, TmpControl.Top + TmpControl.Height + 0.5)
ElseIf TmpControl.Shape = 3 Then
'Es un circulo
If TmpControl.Width < TmpControl.Height Then
TmpRegn = CreateEllipticRgn(TmpControl.Left, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2, TmpControl.Left + TmpControl.Width + 0.5, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width + 0.5)
Else
TmpRegn = CreateEllipticRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2, TmpControl.Top, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height + 0.5, TmpControl.Top + TmpControl.Height + 0.5)
End If
ElseIf TmpControl.Shape = 4 Then
'Es un rectangulo redondeado
If TmpControl.Width > TmpControl.Height Then
TmpRegn = CreateRoundRectRgn(TmpControl.Left, TmpControl.Top, TmpControl.Left + TmpControl.Width + 1, TmpControl.Top + TmpControl.Height + 1, TmpControl.Height / 4, TmpControl.Height / 4)
Else
TmpRegn = CreateRoundRectRgn(TmpControl.Left, TmpControl.Top, TmpControl.Left + TmpControl.Width + 1, TmpControl.Top + TmpControl.Height + 1, TmpControl.Width / 4, TmpControl.Width / 4)
End If
ElseIf TmpControl.Shape = 5 Then
'Es un cuadrado redondeado
If TmpControl.Width > TmpControl.Height Then
TmpRegn = CreateRoundRectRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2, TmpControl.Top, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height + 1, TmpControl.Top + TmpControl.Height + 1, TmpControl.Height / 4, TmpControl.Height / 4)
Else
TmpRegn = CreateRoundRectRgn(TmpControl.Left, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2, TmpControl.Left + TmpControl.Width + 1, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width + 1, TmpControl.Width / 4, TmpControl.Width / 4)
End If
End If
'Si el control es una figura con fondo transparente
If TmpControl.BackStyle = 0 Then
'Combinamos la region en memoria y creamos una nueva
CombineRgn Regn, Regn, TmpRegn, RGN_XOR
If TmpControl.Shape = 0 Then
'Rectangulo
TmpRegn = CreateRectRgn(TmpControl.Left + 1, TmpControl.Top + 1, TmpControl.Left + TmpControl.Width - 1, TmpControl.Top + TmpControl.Height - 1)
ElseIf TmpControl.Shape = 1 Then
'Cuadrado
If TmpControl.Width < TmpControl.Height Then
TmpRegn = CreateRectRgn(TmpControl.Left + 1, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + 1, TmpControl.Left + TmpControl.Width - 1, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width - 1)
Else
TmpRegn = CreateRectRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + 1, TmpControl.Top + 1, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height - 1, TmpControl.Top + TmpControl.Height - 1)
End If
ElseIf TmpControl.Shape = 2 Then
'Ovalo
TmpRegn = CreateEllipticRgn(TmpControl.Left + 1, TmpControl.Top + 1, TmpControl.Left + TmpControl.Width - 0.5, TmpControl.Top + TmpControl.Height - 0.5)
ElseIf TmpControl.Shape = 3 Then
'Circulo
If TmpControl.Width < TmpControl.Height Then
TmpRegn = CreateEllipticRgn(TmpControl.Left + 1, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + 1, TmpControl.Left + TmpControl.Width - 0.5, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width - 0.5)
Else
TmpRegn = CreateEllipticRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + 1, TmpControl.Top + 1, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height - 0.5, TmpControl.Top + TmpControl.Height - 0.5)
End If
ElseIf TmpControl.Shape = 4 Then
'Rectangulo redondeado
If TmpControl.Width > TmpControl.Height Then
TmpRegn = CreateRoundRectRgn(TmpControl.Left + 1, TmpControl.Top + 1, TmpControl.Left + TmpControl.Width, TmpControl.Top + TmpControl.Height, TmpControl.Height / 4, TmpControl.Height / 4)
Else
TmpRegn = CreateRoundRectRgn(TmpControl.Left + 1, TmpControl.Top + 1, TmpControl.Left + TmpControl.Width, TmpControl.Top + TmpControl.Height, TmpControl.Width / 4, TmpControl.Width / 4)
End If
ElseIf TmpControl.Shape = 5 Then
'Cuadrado redondeado
If TmpControl.Width > TmpControl.Height Then
TmpRegn = CreateRoundRectRgn(TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + 1, TmpControl.Top + 1, TmpControl.Left + (TmpControl.Width - TmpControl.Height) / 2 + TmpControl.Height, TmpControl.Top + TmpControl.Height, TmpControl.Height / 4, TmpControl.Height / 4)
Else
TmpRegn = CreateRoundRectRgn(TmpControl.Left + 1, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + 1, TmpControl.Left + TmpControl.Width, TmpControl.Top + (TmpControl.Height - TmpControl.Width) / 2 + TmpControl.Width, TmpControl.Width / 4, TmpControl.Width / 4)
End If
End If
End If
Else
'Crea una region rectangular con estos parametros
TmpRegn = CreateRectRgn(TmpControl.Left, TmpControl.Top, TmpControl.Left + TmpControl.Width, TmpControl.Top + TmpControl.Height)
End If
'Comprueba que el control tiene ancho o conseguiremos extraños resultados
ErrorTest = 0
ErrorTest = TmpControl.Width
If ErrorTest <> 0 Or TypeOf TmpControl Is Line Then
'Combina las regiones
CombineRgn Regn, Regn, TmpRegn, RGN_XOR
End If
Next TmpControl
'Crea las regiones
SetWindowRgn TransForm.hwnd, Regn, True
End Sub