[DUDA] Transparencia de un color

[HJZR4]

Explico. En un form normal, inserto una imagen de una bola, como puedo indicar que el fondo (morado) sea trasparente?

[VirucKingX]

Const LWA_COLORKEY = &H1
Const GWL_EXSTYLE = (-20)
Const WS_EX_LAYERED = &H80000

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.dll" (ByVal hWnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long

Private Sub Form_Load()

Dim Ret As Long
Dim CLR As Long

CLR = &HFFC0FF ' Aca colocas el color que mas deseas esop.
Ret = GetWindowLong(Me.hWnd, GWL_EXSTYLE)
Ret = Ret Or WS_EX_LAYERED
SetWindowLong Me.hWnd, GWL_EXSTYLE, Ret
SetLayeredWindowAttributes Me.hWnd, CLR, 0, LWA_COLORKEY

End Sub

Bye

[HJZR4]

Y como se que color es tal? xDD

[LeandroA]

abri la imagen con algun editor abanzado y fijate el color o bien cambiaselo a rojo y ponele vbred

[HJZR4]

Pero eso, transparenta el color morado, todo el form... Y si sólo quiero que la imágen se vea transparente y que se vea, lo que hay debajo de la imagen, no lo que hay debajo del form.,...

[LeandroA]

hola te paso un modulo para hacerlo con un pictureBox (no con el control image)

Código [Seleccionar] Expandir

Option Explicit
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 CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Private Const RGN_OR As Long = 2&

Private Declare Sub OleTranslateColor Lib "oleaut32.dll" ( _
     ByVal clr As Long, _
     ByVal hpal As Long, _
     ByRef lpcolorref As Long)

Private Type BITMAPINFOHEADER
    biSize As Long
    biWidth As Long
    biHeight As Long
    biPlanes As Integer
    biBitCount As Integer
    biCompression As Long
    biSizeImage As Long
    biXPelsPerMeter As Long
    biYPelsPerMeter As Long
    biClrUsed As Long
    biClrImportant As Long
End Type

Private Type RGBQUAD
    rgbBlue As Byte
    rgbGreen As Byte
    rgbRed As Byte
    rgbReserved As Byte
End Type

Private Type BITMAPINFO
    bmiHeader As BITMAPINFOHEADER
    bmiColors As RGBQUAD
End Type

Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hDC As Long) As Long
Private Declare Function CreateDIBSection Lib "gdi32" (ByVal hDC As Long, pBitmapInfo As BITMAPINFO, ByVal un As Long, ByVal lplpVoid As Long, ByVal handle As Long, ByVal dw As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hDC As Long, ByVal hObject As Long) As Long
Private Declare Function BitBlt Lib "gdi32" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Declare Function GetDIBits Lib "gdi32" (ByVal aHDC As Long, ByVal hBitmap As Long, ByVal nStartScan As Long, ByVal nNumScans As Long, lpBits As Any, lpBI As BITMAPINFO, ByVal wUsage As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hDC As Long) As Long

Private Const BI_RGB As Long = 0&
Private Const DIB_RGB_COLORS As Long = 0&


Public Function MakeFormTransparent(Obj As Object, ByVal lngTransColor As Long)
    Dim hRegion As Long

        hRegion = RegionFromBitmap(Obj, lngTransColor)
        SetWindowRgn Obj.hWnd, hRegion, True
        DeleteObject hRegion

End Function

Private Function RegionFromBitmap(picSource As Object, ByVal lngTransColor As Long) As Long
    Dim lngRetr As Long, lngHeight As Long, lngWidth As Long
    Dim lngRgnFinal As Long, lngRgnTmp As Long
    Dim lngStart As Long
    Dim x As Long, y As Long
    Dim hDC As Long
   
    Dim bi24BitInfo As BITMAPINFO
    Dim iBitmap As Long
    Dim BWidth As Long
    Dim BHeight As Long
    Dim iDC As Long
    Dim PicBits() As Byte
    Dim Col As Long
    Dim OldScaleMode As ScaleModeConstants
   
    OldScaleMode = picSource.ScaleMode
    picSource.ScaleMode = vbPixels
   
    hDC = picSource.hDC
    lngWidth = picSource.ScaleWidth '- 1
    lngHeight = picSource.ScaleHeight - 1

    BWidth = (picSource.ScaleWidth \ 4) * 4 + 4
    BHeight = picSource.ScaleHeight

    'Bitmap-Header
    With bi24BitInfo.bmiHeader
        .biBitCount = 24
        .biCompression = BI_RGB
        .biPlanes = 1
        .biSize = Len(bi24BitInfo.bmiHeader)
        .biWidth = BWidth
        .biHeight = BHeight + 1
    End With
    'ByteArrays in der erforderlichen Größe anlegen
    ReDim PicBits(0 To bi24BitInfo.bmiHeader.biWidth * 3 - 1, 0 To bi24BitInfo.bmiHeader.biHeight - 1)
   
    iDC = CreateCompatibleDC(hDC)
    'Gerätekontextunabhängige Bitmap (DIB) erzeugen
    iBitmap = CreateDIBSection(iDC, bi24BitInfo, DIB_RGB_COLORS, ByVal 0&, ByVal 0&, ByVal 0&)
    'iBitmap in den neuen DIB-DC wählen
    Call SelectObject(iDC, iBitmap)
    'hDC des Quell-Fensters in den hDC der DIB kopieren
    Call BitBlt(iDC, 0, 0, bi24BitInfo.bmiHeader.biWidth, bi24BitInfo.bmiHeader.biHeight, hDC, 0, 0, vbSrcCopy)
    'Gerätekontextunabhängige Bitmap in ByteArrays kopieren
    Call GetDIBits(hDC, iBitmap, 0, bi24BitInfo.bmiHeader.biHeight, PicBits(0, 0), bi24BitInfo, DIB_RGB_COLORS)
   
    'Wir brauchen nur den Array, also können wir die Bitmap direkt wieder löschen.
   
    'DIB-DC
    Call DeleteDC(iDC)
    'Bitmap
    Call DeleteObject(iBitmap)

    lngRgnFinal = CreateRectRgn(0, 0, 0, 0)
    For y = 0 To lngHeight
        x = 0
        Do While x < lngWidth
            Do While x < lngWidth And _
                RGB(PicBits(x * 3 + 2, lngHeight - y + 1), _
                    PicBits(x * 3 + 1, lngHeight - y + 1), _
                    PicBits(x * 3, lngHeight - y + 1) _
                    ) = lngTransColor
               
                x = x + 1
            Loop
            If x <= lngWidth Then
                lngStart = x
                Do While x < lngWidth And _
                    RGB(PicBits(x * 3 + 2, lngHeight - y + 1), _
                        PicBits(x * 3 + 1, lngHeight - y + 1), _
                        PicBits(x * 3, lngHeight - y + 1) _
                        ) <> lngTransColor
                    x = x + 1
                Loop
                If x + 1 > lngWidth Then x = lngWidth
                lngRgnTmp = CreateRectRgn(lngStart, y, x, y + 1)
                lngRetr = CombineRgn(lngRgnFinal, lngRgnFinal, lngRgnTmp, RGN_OR)
                DeleteObject lngRgnTmp
            End If
        Loop
    Next

    picSource.ScaleMode = OldScaleMode
    RegionFromBitmap = lngRgnFinal
End Function


y en el formulario agregas un picture1 con esta imagen

Código [Seleccionar] Expandir

Private Sub Form_Load()
Picture1.AutoRedraw = True

MakeFormTransparent Picture1, vbMagenta
End Sub

Saludos