给你来个明白一点的！~
不知道我来的晚了没？
新建一个模块,把以下代码复制进去:
Option Explicit
' APIs to install our subclassing routines
Private Const GWL_WNDPROC = (-4)
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 CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Function DefWindowProc Lib "user32" Alias "DefWindowProcA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
' These APIs are used to create a pattern brush for each textbox...
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 CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function CreateCompatibleDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function CreatePatternBrush Lib "gdi32" (ByVal hBitmap As Long) As Long
Private Declare Function CreateSolidBrush Lib "gdi32" (ByVal crColor As Long) As Long
Private Declare Function DeleteDC Lib "gdi32" (ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetSysColor Lib "user32" (ByVal nIndex As Long) As Long
Private Declare Function ReleaseDC Lib "user32" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
' Messages which we will be processing in our subclassing routines
Private Const WM_COMMAND As Long = &H111
Private Const WM_CTLCOLOREDIT As Long = &H133
Private Const WM_DESTROY As Long = &H2
Private Const WM_ERASEBKGND As Long = &H14
Private Const WM_HSCROLL As Long = &H114
Private Const WM_VSCROLL As Long = &H115
' A rectangle.
Private Type RECT
Left As Long
Top As Long
Right As Long
Bottom As Long
End Type
' APIs used to keep track of brush handles and process addresses
Private Declare Function GetProp Lib "user32" Alias "GetPropA" (ByVal hwnd As Long, ByVal lpString As String) As Long
Private Declare Function RemoveProp Lib "user32" Alias "RemovePropA" (ByVal hwnd As Long, ByVal lpString As String) As Long
Private Declare Function SetProp Lib "user32" Alias "SetPropA" (ByVal hwnd As Long, ByVal lpString As String, ByVal hData As Long) As Long
' APIs used in our subclassing routine to create the "transparent" effect.
Private Declare Function FillRect Lib "user32" (ByVal hdc As Long, lpRect As RECT, ByVal hBrush As Long) As Long
Private Declare Function GetClientRect Lib "user32" (ByVal hwnd As Long, lpRect As RECT) As Long
Private Declare Function GetParent Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function InvalidateRect Lib "user32" (ByVal hwnd As Long, ByVal lpRect As Long, ByVal bErase As Long) As Long
Private Declare Function LockWindowUpdate Lib "user32" (ByVal hwndLock As Long) As Long
Private Declare Function SetBkMode Lib "gdi32" (ByVal hdc As Long, ByVal nBkMode As Long) As Long
Private Declare Function UpdateWindow Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function WindowFromDC Lib "user32" (ByVal hdc As Long) As Long
Public Function makeTransparentTextbox(aTxt As TextBox)
' Make sure we don't have any typos in our subclassing procedures.
NewWindowProc 0, 0, 0, 0
NewTxtBoxProc 0, 0, 0, 0
' Create a background brush for this textbox, which we will used to give
' the textbox an APPEARANCE of transparency
CreateBGBrush aTxt
' Subclass the textbox's form, IF NOT ALREADY subclassed
If GetProp(GetParent(aTxt.hwnd), "OrigProcAddr") = 0 Then
SetProp GetParent(aTxt.hwnd), "OrigProcAddr", SetWindowLong(GetParent(aTxt.hwnd), GWL_WNDPROC, AddressOf NewWindowProc)
End If
' Subclass the textbox, IF NOT ALREADY subclassed
If GetProp(aTxt.hwnd, "OrigProcAddr") = 0 Then
SetProp aTxt.hwnd, "OrigProcAddr", SetWindowLong(aTxt.hwnd, GWL_WNDPROC, AddressOf NewTxtBoxProc)
End If
End Function
Private Sub CreateBGBrush(aTxtBox As TextBox)
Dim screenDC As Long ' The screen's device context.
Dim imgLeft As Long ' The X location inside the image which we are going to copy from.
Dim imgTop As Long ' The Y location inside the image which we are going to copy from.
Dim picDC As Long ' A temporary DC to pull the form's picture into
Dim picBmp As Long ' the 1x1 bitmap which is created with picDC
Dim aTempBmp As Long ' A temporary bitmap we'll use to create the pattern brush for our textbox
Dim aTempDC As Long ' the temporary device context used to hold aTempBmp
Dim txtWid As Long ' The form's width
Dim txtHgt As Long ' the form's height.
Dim solidBrush As Long ' Solid brush used to color in the bitmap... incase the textbox
' gets sized outside the dimensions of the picture
Dim aRect As RECT ' Rectangle to fill in with solid brush
If aTxtBox.Parent.Picture Is Nothing Then Exit Sub
' Get our form's dimensions, in pixels
txtWid = aTxtBox.Width / Screen.TwipsPerPixelX
txtHgt = aTxtBox.Height / Screen.TwipsPerPixelY
' Get the location within the bitmap picture we're copying from
imgLeft = aTxtBox.Left / Screen.TwipsPerPixelX
imgTop = aTxtBox.Top / Screen.TwipsPerPixelY
' Get the screen's device context
screenDC = GetDC(0)
' Create a device context to hold the form's picture.
picDC = CreateCompatibleDC(screenDC)
picBmp = SelectObject(picDC, aTxtBox.Parent.Picture.Handle)
' Create a temporary bitmap to blt the underlying image onto
aTempDC = CreateCompatibleDC(screenDC)
aTempBmp = CreateCompatibleBitmap(screenDC, txtWid, txtHgt)
DeleteObject SelectObject(aTempDC, aTempBmp)
' create a brush the color of BUTTON_FACE
solidBrush = CreateSolidBrush(GetSysColor(15))
aRect.Right = txtWid
aRect.Bottom = txtHgt
' Fill in the area
FillRect aTempDC, aRect, solidBrush
' clean up our resource
DeleteObject solidBrush
' Transfer the image
BitBlt aTempDC, 0, 0, txtWid, txtHgt, picDC, imgLeft, imgTop, vbSrcCopy
' Check to make sure that a brush hasn't already been made for this one
If GetProp(aTxtBox.hwnd, "CustomBGBrush") <> 0 Then
' If so, then delete it and free its memory before storing the new one's handle.
DeleteObject GetProp(aTxtBox.hwnd, "CustomBGBrush")
End If
' Create a pattern brush from our bitmap and store its handle against
' the textbox's handle
SetProp aTxtBox.hwnd, "CustomBGBrush", CreatePatternBrush(aTempBmp)
' Clean up our temporary DC and bitmap resources
DeleteDC aTempDC
DeleteObject aTempBmp
' Replace the original 1x1 bitmap, releasing the form's picture
SelectObject picDC, picBmp
' Clean up our picture DC and the 1x1 bitmap that was created with it
DeleteDC picDC
DeleteObject picBmp
' Release the screen's DC back to the system... forgetting to do this
' causes a nasty memory leak.
ReleaseDC 0, screenDC
End Sub
Private Function NewWindowProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
' ******************************************************
' SUBCLASSING ROUTINE FOR THE TEXTBOX'S >>>>PARENT<<<<
' ******************************************************
Dim origProc As Long ' The original process address for the window.
Dim isSubclassed As Long ' Whether a certain textbox is subclassed or not.
' I've gotten in the habit of passing 0 values to the subclassing functions before
' actually installing them, just to make sure that I don't have any typos or other
' problems which can be easily detected. As such, if there is a hwnd of 0, its not
' a "valid" message, so we'll just exit right away.
If hwnd = 0 Then Exit Function
' Get the original process address which we stored earlier.
origProc = GetProp(hwnd, "OrigProcAddr")
If origProc <> 0 Then
If (uMsg = WM_CTLCOLOREDIT) Then
' Check to see if our window has a stored value for the original
' process address. If so, we're subclassing this one.
isSubclassed = (GetProp(WindowFromDC(wParam), "OrigProcAddr") <> 0)
If isSubclassed Then
' Invoke the default process... This will set the font, font color
' and other stuff we don't really want to fool with.
CallWindowProc origProc, hwnd, uMsg, wParam, lParam
' Make the words print transparently
SetBkMode wParam, 1
' Return the handle to our custom brush rather than that which
' the default process would have returned.
NewWindowProc = GetProp(WindowFromDC(wParam), "CustomBGBrush")
Else
' The textbox in question isn't subclassed, so we aren't going
' to do anything out of the ordinary. Just invoke the default proc.
NewWindowProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
End If
ElseIf uMsg = WM_COMMAND Then
' Check to see if our window has a stored value for the original
' process address. If so, we're subclassing this one.
isSubclassed = (GetProp(lParam, "OrigProcAddr") <> 0)
If isSubclassed Then
' We are going lock the window from updating while we invalidate
' and redraw it. This prevents flickering.
LockWindowUpdate GetParent(lParam)
' Force windows to redraw the window.
InvalidateRect lParam, 0&, 1&
UpdateWindow lParam
End If
' Invoke the default process
NewWindowProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
If isSubclassed Then LockWindowUpdate 0&
ElseIf uMsg = WM_DESTROY Then
' The window is being destroyed... time to unhook our process so we
' don't cause a big fat error which crashes the application.
' Install the default process address again
SetWindowLong hwnd, GWL_WNDPROC, origProc
' Invoke the default process
NewWindowProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
' Remove our stored value since we don't need it anymore
RemoveProp hwnd, "OrigProcAddr"
Else
' We're not concerned about this particular message, so we'll just
' let it go on its merry way.
NewWindowProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
End If
Else
' A catch-all in case something freaky happens with the process addresses.
NewWindowProc = DefWindowProc(hwnd, uMsg, wParam, lParam)
End If
End Function
Private Function NewTxtBoxProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
' *********************************************
' SUBCLASSING ROUTINE FOR THE >>>>TEXTBOX<<<<
' *********************************************
Dim aRect As RECT
Dim origProc As Long
Dim aBrush As Long
If hwnd = 0 Then Exit Function
' Get the original process address which we stored earlier.
origProc = GetProp(hwnd, "OrigProcAddr")
If origProc <> 0 Then
' We're subclassing! Which is silly, 'cause otherwise we wouldn't be in
' this function, however we double check the process address just in case.
If uMsg = WM_ERASEBKGND Then
' We're going to get our custom brush for this textbox and fill the
' textbox's background area with it...
aBrush = GetProp(hwnd, "CustomBGBrush")
If aBrush <> 0 Then
' Get the area dimensions to fill
GetClientRect hwnd, aRect
' Fill it with our custom brush
FillRect wParam, aRect, aBrush
' Tell windows that we took care of the "erasing"
NewTxtBoxProc = 1
Else
' Something happened to our custom brush :-\ We'll just invoke
' the default process
NewTxtBoxProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
End If
ElseIf uMsg = WM_HSCROLL Or uMsg = WM_VSCROLL Then
' We are scrolling, either horizontally or vertically. This requires
' us to totally repaint the background area... so we'll lock the
' window updates so we don't see any of the freaky flickering
LockWindowUpdate GetParent(hwnd)
' Invoke the default process so the user actually get's the scroll
' they want
NewTxtBoxProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
' Force window to repaint itself
InvalidateRect hwnd, 0&, 1&
UpdateWindow hwnd
' Release the update lock
LockWindowUpdate 0&
ElseIf uMsg = WM_DESTROY Then
' The textbox's parent is closing / destroying, so we need to
' unhook our subclassing routine ... or bad things happen
' Clean up our brush object... muy importante!!!
aBrush = GetProp(hwnd, "CustomBGBrush")
' Delete the brush object, freeing its resource.
DeleteObject aBrush
' Remove our values we stored against the textbox's handle
RemoveProp hwnd, "OrigProcAddr"
RemoveProp hwnd, "CustomBGBrush"
' Replace the original process address
SetWindowLong hwnd, GWL_WNDPROC, origProc
' Invoke the default "destroy" process
NewTxtBoxProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
Else
' We're not interested in this message, so we'll just let it truck
' right on thru... invoke the default process
NewTxtBoxProc = CallWindowProc(origProc, hwnd, uMsg, wParam, lParam)
End If
Else
' A catch-all in case something freaky happens with the process addresses.
NewTxtBoxProc = DefWindowProc(hwnd, uMsg, wParam, lParam)
End If
End Function
然后在窗体Form里
Private Sub Form_Load()
makeTransparentTextbox Text1 'Text1是需要透明的文本框
End Sub
不能用你向我扔砖
2007-09-22 12:07
