[RESOLVED] Gradient in a Round Shape

How could i create a multi-color smooth looking color gradient
in a round shape ... maybe even like in the
Round Shape Control ? , or changing the
shape of a PictureBox Control to Round in which a Color Gradient
would appear ?

You need to create a region, basically clipping off parts of the form.

I don't have any gradient code handy right now but there are lots at www.pscode.com/vb if you search for gradient.

But try starting a new VB project and running this code...hopefully my memory serves me correctly...

Code:

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Option Explicit

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 SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long

Private Sub Form_Load()
    Me.BorderStyle = 0
    Me.Caption = vbNullString
    Me.ScaleMode = vbPixels
    Me.AutoRedraw = True 'For gradient.
   
    'Draw gradient here...

    'Create rounded region.
    '15, 15 is radius of rounded corners.
    'Higher the value, the more round they are.
    Dim lonRgn As Long
    lonRgn = CreateRoundRectRgn(0, 0, Me.ScaleWidth, Me.ScaleHeight, 15, 15)
    SetWindowRgn Me.hWnd, lonRgn, True
End Sub

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In this example I used a form, but you can do it to a PictureBox also.

Shape control? Not really possible as far as I know, you don't have control over how that is painted or when it is painted.

Picturebox you have control over but requires some API usage. Getting a smooth gradient is relatively simple, but getting a smooth circular boundary is not -- the best it may look like is a circular shape control. If that is all you are expecting, then...

If you plan on having like hundreds of these, then other options can be employed which include creating these in a paint program and saving them as a transparent GIF, then using the Image control. Other options could be available too, but we would need more details.

1. Look at this example pertaining to the GradientFill API. You will probably want to use it vs creating your own gradient routines -- your choice of course

2. Your picturebox should be AutoRedraw=True, no borders. Then call this command in your Form_Load function and add the 2 declarations to your form. The code below shapes the picturebox.

Edited: I may have misunderstood, if circular shape is needed, use the APIs below. If rectangle with rounded corners is needed, use the ones DigiRev gave you.

Code:

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' declarations section
Private Declare Function CreateEllipticRgn Lib "gdi32.dll" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function SetWindowRgn Lib "user32.dll" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long

Private Sub Form_Load()
    Dim hRgn As Long
    Picture1.ScaleMode = vbPixels
    hRgn = CreateEllipticRgn(0, 0, Picture1.ScaleWidth, Picture1.ScaleHeight)
    SetWindowRgn Picture1.hWnd, hRgn, True
End Sub

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Thanks a bunch , DigiRev and LaVolpe ....that was quick and easy !

i can figure the rest of the Gradient code
to display in the Round or Elliptical PictureBox shapes

Code:

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Option Explicit

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 SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Private Declare Function CreateEllipticRgn Lib "gdi32.dll" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long

Private Sub Form_Load()
   
    Picture1.BorderStyle = 0
    Picture1.ScaleMode = vbPixels
    Picture1.AutoRedraw = True 'For gradient.
   
    'Draw gradient here...

    'Create rounded region.
    '15, 15 is radius of rounded corners.
    'Higher the value, the more round they are.
    'Dim lonRgn As Long
    'lonRgn = CreateRoundRectRgn(0, 0, Picture1.ScaleWidth, Picture1.ScaleHeight, 50, 50)
    'SetWindowRgn Picture1.hWnd, lonRgn, True


    Dim hRgn As Long
    hRgn = CreateEllipticRgn(200, 0, Picture1.ScaleWidth, Picture1.ScaleHeight)
    SetWindowRgn Picture1.hWnd, hRgn, True



End Sub

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Cool. If you want to give your shapes a solid color border that can be done too. Just let us know.

Cool. If you want to give your shapes a solid color border that can be done too. Just let us know.



OK, great , that would also be very helpful...
how would i go about doing that also ?

One more question or potential problem or conflict ??

i'm developing an Application that requires GDI-Plus
any problems with GDI-Plus -vs- regular GDI ??
( Win98 on up. ) including Vista

Simple, change vbRed to border color you want (do not use system colors, i.e., don't use vbButonFace). But order is important here
1. Do your gradient
2. Create your hRgn before doing the border, and don't assign it via SetWindowRgn yet
3. Draw the border
4. Assign region via SetWindowRgn

Code:

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' 3 more apis
Private Declare Function FrameRgn Lib "gdi32.dll" (ByVal hdc As Long, ByVal hRgn As Long, ByVal hBrush As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function CreateSolidBrush Lib "gdi32.dll" (ByVal crColor As Long) As Long
Private Declare Function DeleteObject Lib "gdi32.dll" (ByVal hObject As Long) As Long

' outline code, add to your project where needed
Dim hBrush As Long
    hBrush = CreateSolidBrush(vbRed)
    FrameRgn Picture1.hdc, hRgn, hBrush, 1, 1
    DeleteObject hBrush

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Edited: FYI, the reason why order is important is that if your gradient is done after border, the gradient will probably overpaint the border. The region if referenced after using SetWindowRgn may be invalid (depends on O/S) so nothing will be done. If for some reason a border needs to be painted after SetWindowRgn is called, recreate the region, frame the region then destroy the region with DeleteObject hRgn. No need to call SetWindowRgn again.

Quote:

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Originally Posted by MaxRaceSoftware

One more question or potential problem or conflict ??
i'm developing an Application that requires GDI-Plus
any problems with GDI-Plus -vs- regular GDI ??
( Win98 on up. ) including Vista

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Generally -- no conflicts. However, handles and objects used/created by one very rarely can be used by the other.