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" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Private Sub Form_Load()
Dim rtn As Long
rtn = GetWindowLong(hwnd, GWL_EXSTYLE) '取窗口原先的样式
rtn = rtn Or WS_EX_LAYERED '使窗体添加上新的样式WS_EX_LAYERED
SetWindowLong hwnd, GWL_EXSTYLE, rtn '把新的样式赋给窗体
SetLayeredWindowAttributes hwnd, 0, 200, LWA_ALPHA
End Sub
Public Declare Function SetLayeredWindowAttributes Lib "user32" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Public Declare Function SetLayeredWindowAttributes Lib "user32" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Public Const WS_EX_LAYERED = &H80000
Public Const GWL_EXSTYLE = (-20)
Public Const LWA_ALPHA = &H2
Public Const LWA_COLORKEY = &H1
Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
【声明】
Private Declare Function SetLayeredWindowAttributes Lib "user32" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
【说明】
透明窗体
【参数表】
hwnd -- 透明窗体的句柄
crKey -- 为颜色值
bAlpha -- 透明度,取值范围是[0,255]
dwFlags -- 透明方式,可以取两个值:当取值为LWA_ALPHA时,crKey参数无效,bAlpha参数有效;当取值为LWA_COLORKEY时,bAlpha参数有效而窗体中的所有颜色为crKey的地方将变为透明
【其它】
'系统WIN2000
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" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
Private Const WS_EX_LAYERED = &H80000
Private Const GWL_EXSTYLE = (-20)
Private Const LWA_ALPHA = &H2
Private Const LWA_COLORKEY = &H1
'形状不规则的窗体
Private Sub Command1_Click()
Dim rtn As Long
rtn = GetWindowLong(hwnd, GWL_EXSTYLE)
rtn = rtn Or WS_EX_LAYERED
SetWindowLong hwnd, GWL_EXSTYLE, rtn
SetLayeredWindowAttributes hwnd, &HFF0000, 0, LWA_COLORKEY '将扣去窗口中的蓝色
End Sub
'透明窗体
Private Sub Command2_Click()
Dim rtn As Long
rtn = GetWindowLong(hwnd, GWL_EXSTYLE)
rtn = rtn Or WS_EX_LAYERED
SetWindowLong hwnd, GWL_EXSTYLE, rtn
Text1 = VScroll1.Value
SetLayeredWindowAttributes hwnd, 0, 150, LWA_ALPHA
End Sub
SetLayeredWindowAttributes
The SetLayeredWindowAttributes function sets the opacity and transparency color key of a layered window.
BOOL SetLayeredWindowAttributes(
HWND hwnd, // handle to the layered window
COLORREF crKey, // specifies the color key
BYTE bAlpha, // value for the blend function
DWORD dwFlags // action
);
Return Values
If the function succeeds, the return value is nonzero.
Requirements
Windows NT/2000/XP: Included in Windows 2000 and later.
Windows 95/98/Me: Unsupported.
Header: Declared in Winuser.h; include Windows.h.
Library: Use User32.lib.
Private Const WS_EX_LAYERED = &H80000
Private Const GWL_EXSTYLE = (-20)
Private Const LWA_ALPHA = &H2
Private Const LWA_COLORKEY = &H1
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" (ByVal hwnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
在2000下就可以了,是API函数,
Declare Function CreateCompatibleBitmap Lib "gdi32" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Sub Command1_Click()
End
End Sub
'透明窗体
Private Sub Form_Load()
Dim hBitmap
Me.AutoRedraw = True
hBitmap = CreateCompatibleBitmap(Me.hdc, 0, 0)
SelectObject Me.hdc, hBitmap
Me.Refresh
End Sub