아래는 class입니다.
Imports System
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
'Translation from C# by Dj Den4ik
Public Class PerPixelAlphaForm
'Implements Windows.Forms.IWin32Window
Public Structure ARGB
Public Blue As Byte
Public Green As Byte
Public Red As Byte
Public Alpha As Byte
End Structure
Public Structure BLENDFUNCTION
Public BlendOp As Byte
Public BlendFlags As Byte
Public SourceConstantAlpha As Byte
Public AlphaFormat As Byte
End Structure
Public Const ULW_COLORKEY As Int32 = &H1
Public Const ULW_ALPHA As Int32 = &H2
Public Const ULW_OPAQUE As Int32 = &H4
Public Const AC_SRC_OVER As Byte = &H0
Public Const AC_SRC_ALPHA As Byte = &H1
Public Declare Function UpdateLayeredWindow Lib "user32" Alias "UpdateLayeredWindow" (ByVal hwnd As IntPtr, ByVal hdcDst As IntPtr, ByRef pptDst As Point, ByRef psize As Size, ByVal hdcSrc As IntPtr, ByRef pprSrc As Point, ByVal crKey As Int32, ByRef pblend As BLENDFUNCTION, ByVal dwFlags As Int32) As Boolean
Public Declare Function GetDC Lib "user32" Alias "GetDC" (ByVal hWnd As IntPtr) As IntPtr
Public Declare Function ReleaseDC Lib "user32" Alias "ReleaseDC" (ByVal hWnd As IntPtr, ByVal hDC As IntPtr) As Integer
Public Declare Function CreateCompatibleDC Lib "gdi32.dll" Alias "CreateCompatibleDC" (ByVal hDC As IntPtr) As IntPtr
Public Declare Function DeleteDC Lib "gdi32.dll" Alias "DeleteDC" (ByVal hDC As IntPtr) As Boolean
Public Declare Function SelectObject Lib "gdi32.dll" Alias "SelectObject" (ByVal hDC As IntPtr, ByVal hObject As IntPtr) As IntPtr
Public Declare Function DeleteObject Lib "gdi32.dll" Alias "DeleteObject" (ByVal hObject As IntPtr) As Boolean
Public Sub SetBitmap(ByVal bitmap As Bitmap, ByVal opacity As Byte, ByVal frm As Form)
If bitmap.PixelFormat <> PixelFormat.Format32bppArgb Then Throw New ApplicationException("The bitmap must be 32ppp with alpha-channel.")
' The ideia of this is very simple,
' 1. Create a compatible DC with screen;
' 2. Select the bitmap with 32bpp with alpha-channel in the compatible DC;
' 3. Call the UpdateLayeredWindow.
Dim screenDc As IntPtr = GetDC(IntPtr.Zero)
Dim memDc As IntPtr = CreateCompatibleDC(screenDc)
Dim hBitmap As IntPtr = IntPtr.Zero
Dim oldBitmap As IntPtr = IntPtr.Zero
Try
hBitmap = bitmap.GetHbitmap(Color.FromArgb(0)) ' grab a GDI handle from this GDI+ bitmap
oldBitmap = SelectObject(memDc, hBitmap)
Dim size As New Size(bitmap.Width, bitmap.Height)
Dim pointSource As New Point(0, 0)
Dim topPos As New Point(frm.Left, frm.Top)
Dim blend As New BLENDFUNCTION
blend.BlendOp = AC_SRC_OVER
blend.BlendFlags = 0
blend.SourceConstantAlpha = opacity
blend.AlphaFormat = AC_SRC_ALPHA
UpdateLayeredWindow(frm.Handle, screenDc, topPos, size, memDc, pointSource, 0, blend, ULW_ALPHA)
Finally
ReleaseDC(IntPtr.Zero, screenDc)
If hBitmap <> IntPtr.Zero Then
SelectObject(memDc, oldBitmap)
DeleteObject(hBitmap)
End If
DeleteDC(memDc)
End Try
End Sub
End Class
아래는 폼입니다.
Dim ppaf As New PerPixelAlphaForm
Dim MainBack As Bitmap = My.Resources.mainback
Dim bmp As New Bitmap(MainBack)
Protected Overrides ReadOnly Property CreateParams() As System.Windows.Forms.CreateParams
Get
Dim SecPerm As New Security.Permissions.SecurityPermission(Security.Permissions.PermissionState.Unrestricted)
SecPerm.Demand()
' Extend the CreateParams property of the Button class.
Dim cp As System.Windows.Forms.CreateParams = MyBase.CreateParams
' Update the button Style.
cp.ExStyle = &H80000
Return cp
End Get
End Property
Public Sub redraw()
Me.BackgroundImage = MainBack
bmp.Dispose()
bmp = New Bitmap(MainBack)
For Each ctrl As Control In Me.Controls
Application.DoEvents()
ctrl.DrawToBitmap(bmp, ctrl.Bounds)
Next
Me.Region = New Region()
ppaf.SetBitmap(bmp, 255, Me)
End Sub
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
Const WM_MOUSEMOVE As Int32 = &H200
Const WM_NCLBUTTONDOWN As Int32 = &HA1
Const HTCAPTION As Int32 = 2
If m.Msg = WM_MOUSEMOVE Then
MyBase.Capture = False
Dim message As New Message
With message
.HWnd = Me.Handle
.Msg = WM_NCLBUTTONDOWN
.WParam = HTCAPTION
.LParam = 0&
End With
MyBase.WndProc(message)
End If
MyBase.WndProc(m)
End Sub
PNG-24를 지원합니다.
Alpha-blending으로 form을 투명화합니다.
출저 : http://pastesite.com/22086 & MORE