form1.frm

新手学习vb语言的实用资料于其对计算机语言做出相应了解的教材

VERSION 5.00
Begin VB.Form Form2 
   BackColor       =   &H00FFFF80&
   Caption         =   "中间有椭圆透明洞口的窗体"
   ClientHeight    =   2835
   ClientLeft      =   1140
   ClientTop       =   1515
   ClientWidth     =   4200
   LinkTopic       =   "Form1"
   PaletteMode     =   1  'UseZOrder
   ScaleHeight     =   189
   ScaleMode       =   3  'Pixel
   ScaleWidth      =   280
End
Attribute VB_Name = "Form2"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Private Declare Function CreateRectRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CreateEllipticRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long
Private Declare Function CombineRgn Lib "gdi32" (ByVal hDestRgn As Long, ByVal hSrcRgn1 As Long, ByVal hSrcRgn2 As Long, ByVal nCombineMode As Long) As Long
Private Declare Function SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Long) As Long

Private Sub Form_Resize()
Const RGN_DIFF = 4

Dim outer_rgn As Long
Dim inner_rgn As Long
Dim combined_rgn As Long
Dim wid As Single
Dim hgt As Single
Dim border_width As Single
Dim title_height As Single

    If WindowState = vbMinimized Then Exit Sub
    
    ' Create the regions.
    wid = ScaleX(Width, vbTwips, vbPixels)
    hgt = ScaleY(Height, vbTwips, vbPixels)
    outer_rgn = CreateRectRgn(0, 0, wid, hgt)
    
    border_width = (wid - ScaleWidth) / 2
    title_height = hgt - border_width - ScaleHeight
    inner_rgn = CreateEllipticRgn( _
        border_width + ScaleWidth * 0.1, _
        title_height + ScaleHeight * 0.1, _
        ScaleWidth * 0.9, ScaleHeight * 0.9)

    ' Subtract the inner region from the outer.
    combined_rgn = CreateRectRgn(0, 0, 0, 0)
    CombineRgn combined_rgn, outer_rgn, _
        inner_rgn, RGN_DIFF
    
    ' Restrict the window to the region.
    SetWindowRgn hWnd, combined_rgn, True
End Sub