[AS3]as3.0写的一个滚动条代码实例flash滚动条

[AS3]as3.0写的一个滚动条代码实例

function scrollbar(scrollObject:Sprite, scrollDisplay:Sprite, scrollBar:Sprite, scrollBarLine:Sprite) { 
        var ScrollDrag:Boolean = false; 
        var scrollBarscrollBar_y:Number = scrollBar.y = scrollBar.y; 
        var scrollObjectscrollObject_y:Number = scrollObject.y = scrollBar_y; 
        var wheel:Boolean = false; 
        scrollObject.mask = scrollDisplay; 
        scrollBarLine.height = scrollDisplay.height; 
        scrollBar.height = scrollBarLine.height/(scrollObject.height/scrollBarLine.height); 
        scrollObject.addEventListener(MouseEvent.ROLL_OVER, function(){ 
                wheel = true; 
        }); 
        scrollObject.addEventListener(MouseEvent.MOUSE_OUT, function(){ 
                wheel = false; 
        }); 
        stage.addEventListener(MouseEvent.MOUSE_WHEEL, function(e:MouseEvent){ 
                if(wheel) { 
                        if(e.delta > 0) { 
                                scrollBar.y-= Math.abs(e.delta); 
                                if(scrollBar.y <= scrollBar_y) scrollBar.y = scrollBar_y; 
                        }else{ 
                                scrollBar.y+= Math.abs(e.delta); 
                                if((scrollBar.y - scrollBar_y) >= (scrollBarLine.height - scrollBar.height)) scrollBar.y = scrollBar_y + (scrollBarLine.height - scrollBar.height); 
                        } 
                        scrollObject.y = scrollObject_y - (scrollBar.y - scrollBar_y)*(scrollObject.height/scrollBarLine.height); 
                } 
        }) 
        stage.addEventListener(Event.ENTER_FRAME, function(){ 
                if(ScrollDrag) { 
                        scrollObject.y = scrollObject_y - (scrollBar.y - scrollBar_y)*(scrollObject.height/scrollBarLine.height); 
                } 
        }); 
        scrollBar.addEventListener(MouseEvent.MOUSE_DOWN, function(){ 
                ScrollDrag = true; 
                scrollBar.startDrag(false, new Rectangle(scrollBar.x, scrollBar_y, 0, scrollBarLine.height - scrollBar.height)); 
        }); 
        stage.addEventListener(MouseEvent.MOUSE_UP, function(){ 
                if(ScrollDrag) { 
                        ScrollDrag = false; 
                        scrollBar.stopDrag(); 
                } 
        }); 
}