窗口句柄的案例
获取窗口句柄
案例说明
本例实现窗口句柄的获取。
实现过程
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 Sub Form_Activate()
On Error Resume Next
For i = 0 To 150 Step 2.5
SetLayeredWindowAttributes Me.hwnd, 0, i, LWA_ALPHA
DoEvents
Next i
End Sub
Private Sub Form_load()
Dim rtn As Long
rtn = GetWindowLong(Me.hwnd, GWL_EXSTYLE)
rtn = rtn Or WS_EX_LAYERED
SetWindowLong Me.hwnd, GWL_EXSTYLE, rtn
SetLayeredWindowAttributes Me.hwnd, 0, 0, LWA_ALPHA
End Sub
