信息之舟电脑软件应用栏目编者按： ---- 7、编写事件代码：  

// “Constructor” 事件代码
// *** begin constructor event ***
//
is_PicNormal = this.PictureName
is_PicDisabled = "Disabled状态图片.bmp"
is_PicMouseOver = "MouseOver状态图片.bmp"
is_PicClickDown = "ClickDown状态图片.bmp"
in_State = 0

sb_SuppressHoverBorder = FALSE
//
// *** end constructor event ***

// “MouseMove” 事件代码
// *** begin mousemove event ***
//
rect lr_Border

if not ib_MouseCaptured then
    if flags < > 1 then
        this.PictureName = is_PicMouseOver
    else
        // Left Button Down
        this.PictureName = is_PicClickDown
    end if
    in_State = 1

    SetCapture(handle(this))
    ib_MouseCaptured = TRUE

    if not sb_SuppressHoverBorder then
        lr_Border.left = 0
        lr_Border.top = 0
        lr_Border.right = UnitsToPixels
(this.Width, XUnitsToPixels!)
        lr_Border.bottom = UnitsToPixels
(this.Height, YUnitsToPixels!)

        if flags < > 1 then
            DrawEdge(GetDC(handle(this)),
lr_Border, 4, 1+2+4+8)
        else
            // Left Button Down
            DrawEdge(GetDC(handle(this)),  
lr_Border, 2, 1+2+4+8)
        end if

    end if

else

    // 检测鼠标是否滑出按钮区域？
    if (XPos < 0 or YPos < 0) or (XPos >  
this.Width or YPos > this.Height) then
        ib_MouseCaptured = FALSE
        ReleaseCapture()

        in_State = 0
        this.PictureName = is_PicNormal

    end if

end if

return 1
//
// *** end mousemove event ***

// “LButtonDown” 事件代码
// *** begin lbuttondown event ***
//
rect lr_Border

if ib_MouseCaptured then
    ib_MouseCaptured = FALSE
    ReleaseCapture()
end if

in_State = 2
this.PictureName = is_PicClickDown

SetCapture(handle(this))
ib_MouseCaptured = TRUE

if not sb_SuppressHoverBorder then
    lr_Border.left = 0
    lr_Border.top = 0
    lr_Border.right = UnitsToPixels
(this.Width, XUnitsToPixels!)
    lr_Border.bottom = UnitsToPixels
(this.Height, YUnitsToPixels!)

    DrawEdge(GetDC(handle(this)),  
lr_Border, 2, 1+2+4+8)
end if

return 1
//
// *** end lbuttondown event ***

// “LButtonUp” 事件代码
// *** begin lbuttonup event ***
//
rect lr_Border

if ib_MouseCaptured then
    ib_MouseCaptured = FALSE
    ReleaseCapture()
end if

if (XPos < 0 or YPos < 0) or (XPos >  
this.Width or YPos > this.Height) then
    in_State = 0
    this.PictureName = is_PicNormal

else
    in_State = 1
    this.PictureName = is_PicHover

    SetCapture(handle(this))
    ib_MouseCaptured = TRUE

    if not sb_SuppressHoverBorder then
        lr_Border.left = 0
        lr_Border.top = 0
        lr_Border.right = UnitsToPixels
(this.Width, XUnitsToPixels!)
        lr_Border.bottom = UnitsToPixels
(this.Height, YUnitsToPixels!)
        DrawEdge(GetDC(handle(this)),
lr_Border, 4, 1+2+4+8)
    end if

end if

// 产生Clicked事件
this.event post clicked()
return 1

//
// *** end lbuttonup event ***

// “Other” 事件代码
// *** begin other event ***
//
if message.number = 533 and ib_MouseCaptured then
    // wm_CaptureChanged
    ib_MouseCaptured = FALSE
    in_State = 0
    this.PictureName = is_PicNormal
    return 1
end if

return 0
//
// *** end other event ***
----　 四、简要说明  

---- 1、ib_MouseCaptured变量是作为MouseMove事件的刷新控件图片的信号灯及判断是否已安装了鼠标捕捉器；  

---- 2、sb_SuppressHoverBorder变量，默认值为FALSE，当值为TRUE时，控件不绘制凸或凹边框；  

---- 3、“Other”事件，当鼠标捕捉器被释放或被替换时会触发WM_CAPTURECHANGED事件，例如：您在Clicked事件中调用MessageBox函数时，将触发WM_CAPTURECHANGED事件，在此事件代码中恢复按钮到Normal状态。

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