source: trunk/ab5.0/ablib/TestCase/UI_Sample/CheckBoxTest.ab@ 664

/*
レイヤードウィンドウを使用しているのでWindows 2000以上が必要。
チェックボックスの状態により透明度が変わるという例。
*/

#require <Classes/ActiveBasic/Windows/UI/Form.ab>
#require <Classes/ActiveBasic/Windows/UI/Application.ab>
#require <Classes/ActiveBasic/Windows/UI/CheckBox.ab>

#resource "UI_Sample.rc"

Imports ActiveBasic.Windows.UI

Const LWA_ALPHA = 2
Const WS_EX_LAYERED = &h00080000
Declare Function SetLayeredWindowAttributes Lib "user32" (hwnd As HWND, crKey As COLORREF, bAlpha As Byte, dwFlags As DWord) As BOOL

Class MyForm
    Inherits Form
Public
    Sub MyForm()
        CreateForm()

        Dim wpFont = GetStockObject(DEFAULT_GUI_FONT) As WPARAM

        checkBox = New CheckBox
        With checkBox
            .Create(This, 0, 0, 0)
            .Move(20, 20, 200, 20)
            .Text = "半透明化"
            .ThreeState = True
            .SendMessage(WM_SETFONT, wpFont, 0)
            .AddClick(AddressOf(OnClick))
        End With
        OnClick(This, Args.Empty)
        Show(SW_SHOWDEFAULT)
    End Sub
Protected
    Override Sub GetCreateStruct(ByRef cs As CREATESTRUCT)
        Super.GetCreateStruct(cs)
        With cs
            .style = WS_CAPTION Or WS_BORDER Or WS_SYSMENU Or WS_DLGFRAME Or WS_MINIMIZEBOX
            .dwExStyle = WS_EX_LAYERED
            .cx = 320
            .cy = 240
        End With
    End Sub

Private
    Sub OnClick(sender As Object, e As Args)
        Dim alpha As Byte
        Dim state = checkBox.State
        Select Case state
            Case CheckState.Unchecked
                alpha = 255
            Case CheckState.Checked
                alpha = 200
            Case CheckState.Indeterminate
                alpha = 100
        End Select
        SetLayeredWindowAttributes(This, 0, alpha, LWA_ALPHA)
    End Sub

    checkBox As CheckBox
End Class

Control.Initialize(GetModuleHandle(0))

Dim f = New MyForm
Application.Run(f)