powerbuilder:PowerBuilder制作IE风格的图标按钮

---- 本文介绍在PowerBuilder中实现IE风格图标按钮窍门技巧在C Builder开发工具中有种图标按钮(SpeedButton)这种按钮可以在鼠标移入按钮后在图片周围会出现凸出边框鼠标移出按钮后边框消失而在PowerBuilder中没有提供这种功能按钮为了使开发应用界面更丰富我们使用自定义图形Control控件(Picture)扩展并实现了此功能这种思路方法设计出简洁实用  

---- 、实现功能  

---- 按钮可以显示 4种状态图形:  

---- 1、Normal状态；  

---- 2、Disabled状态；  

---- 3、MouseOver状态(鼠标进入按钮区)；  

---- 4、ClickDown状态(鼠标按下)  

---- 2、关键思路方法  

---- 1、当鼠标进入按钮区域时Control控件图片改换成MouseOver状态图片并设置状态信号；  

---- 2、鼠标滑入按钮区域后用Windows APISetCapture来捕获鼠标输入消息跟踪鼠标位置；  

---- 3、当监测到鼠标滑出按钮区域时用ReleaseCapture释放鼠标捕获恢复按钮图片到Normal状态并设置状态信号；  

---- 4、改变Control控件图片(PictureName)前先用ReleaseCapture释放鼠标捕获然后改变PictureName属性值接着重新SetCapture改变图片后PowerBuilder重新建立了Control控件窗口窗口句柄(hWnd)也随的改变了  

---- 3、设计过程  

---- 1、新建“User Object” -〉选择VisualStandard类 -〉选择“Picture”；  

---- 2、定义全局或局部外部:  

// *******************************
// Declare External Functions
// *******************************
function ulong SetCapture
(ulong hwnd) library "user32.dll"
function boolean ReleaseCapture
(ulong hwnd) library "user32.dll"
function boolean DrawEdge(ulong hdc,
ref rect qrc, u edge, u grfFlags)  
library "user32.dll"
---- 3、定义结构数据类型  

RECT
{
    long left
    long top
    long right
    long bottom
}
---- 4、定义Control控件共享变量:  

// *******************************
// Declare Shared Variables
// *******************************
boolean sb_SuppressHoverBorder
---- 5、定义Control控件例子变量:  

// *******************************
// Declare Instance Variables
// *******************************
Private:
boolean ib_MouseCaptured

Public:
is_PicNormal
is_PicDisabled
is_PicMouseOver
is_PicClickDown
in_State
---- 6、定义用户事件:  

// *******************************
// Declare User Events
// *******************************
Event Name="mousemove",   ID="pbm_mousemove"
Event Name="lbuttondown", ID="pbm_lbuttondown"
Event Name="lbuttonup",   ID="pbm_lbuttonup"
---- 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

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

    SetCapture(handle(this))
    ib_MouseCaptured = TRUE

     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!)

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

    end



    // 检测鼠标是否滑出按钮区域？
     (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

end

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

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

ib_MouseCaptured then
    ib_MouseCaptured = FALSE
    ReleaseCapture
end

in_State = 2
this.PictureName = is_PicClickDown

SetCapture(handle(this))
ib_MouseCaptured = TRUE

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

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

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

ib_MouseCaptured then
    ib_MouseCaptured = FALSE
    ReleaseCapture
end

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


    in_State = 1
    this.PictureName = is_PicHover

    SetCapture(handle(this))
    ib_MouseCaptured = TRUE

     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

end

// 产生Clicked事件
this.event post clicked
1

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

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

0
//
// *** end other event ***
----　 4、简要介绍说明  

---- 1、ib_MouseCaptured变量是作为MouseMove事件刷新Control控件图片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Control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MessageBox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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