如何製作 “透明表單” ( Transparent Form ) 特效
如何製作 "透明表單" ( Transparent Form ) 特效
<< VB.Net >>
設定Opacity 屬性 : 表單的透明度等級。預設值為 1.00。
Opacity 屬性可讓您指定表單和其控制項的透明度等級。
當將這個屬性設為小於 100% (1.00) 的值時，整個表單 (包括框線) 將變得更為透明。
將這個屬性設為 0% (0.00) 的值則使表單完全不可見。
如 :
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
Me.Opacity = 0.5
End Sub
您可以使用這個屬性，提供不同等級的透明度，或提供效果，例如將表單漸層引入或引出視界。
您可以將 Opacity 屬性設為值 0% (0.00)，並逐漸增加數值直至它達到 100% (1.00)，將表單漸層引入視界。
如 :
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
Opacity = 0
End Sub
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As PaintEventArgs) Handles MyBase.Paint
For dblLoop As System.Double = 0.01 To 1 Step 0.01
Opacity = dblLoop
Application.DoEvents()
Threading.Thread.Sleep(12)
Next
End Sub
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<< VB6 >>
Call API SetLayeredWindowAttributes
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 Command1_Click()
MakeTransparent hwnd, 155
End Sub
' Para1 傳 Handle Value , Para2 傳 1 ~ 254 之間的值 , 值越小透明度越高
Sub MakeTransparent(ByVal hwnd As Long, Perc As Byte)
If (Perc > 0 Or Perc < 255) And Len(Environ("OS")) > 0 Then
SetWindowLong hwnd, -20, GetWindowLong(hwnd, -20) + 524288
SetLayeredWindowAttributes hwnd, 0, Perc, 2
End If
End Sub
API 說明如下 :
GetWindowLong :
The GetWindowLong function retrieves information about the specified window.
The function also retrieves the 32-bit (long) value at the specified offset into the extra window memory of a window.
SetWindowLong :
The SetWindowLong function changes an attribute of the specified window.
The function also sets a 32-bit (long) value at the specified offset into the extra window memory of a window.
SetWindowLong :
The SetLayeredWindowAttributes function sets the opacity and transparency color key of a layered window.
( API 說明請參考 API Guide )
