FLEX 仿Google联想框效果

FLEX--仿Google联想框效果--现在好多地方都用到了这样的效果,当然,现在Google下线了,不让用了,但是跟网上说的一样,想办法,它还是能出来的

首先是事件源，也就是从何而起，如下的一个输入框：

然后就是处理效果，这些内容都是从数据库得到的数据，动态的查出的。

import mx.collections.ArrayCollection; 
            import mx.events.FlexMouseEvent; 
            import mx.events.ListEvent; 
            import mx.managers.PopUpManager; 

            import resources.com.list.Association; 

            // 经过渲染的联想结果List 
            private var list:Association; 
            // 临时字符串,用于判断当keyUp事件发生时,联想框的值是否发生改变,如未改变则不联想 
            private var temp:String = ''; 
            private function changeAssociation():void{ 
                temp=''; 
                txtAssociation.text=''; 
                associationResult=null; 
                if(list != null){ 
                    PopUpManager.removePopUp(list); 
                    list = null; 
                    // 清空临时字符串 
                } 
        } 
            private function associate():void { 
                var str:String = txtAssociation.text; 
                if(str.length<2){ 
                    associationResult=null; 
                } 
                if (str != temp) { 
                    if(str.length <2){ 
                         if(list != null){ 
                             PopUpManager.removePopUp(list); 
                             list = null; 
                             // 清空临时字符串 
                            temp = ''; 
                        } 
                         return; 
                    } 
                    temp = str; 

                    var params:Object = {}; 
                    params['areaNO'] = cbxArea.selectedItem.data; 
                 params['netType'] = cbxNetType.selectedItem.data; 
                    params['str'] = str; 
                    params['handle'] = 'associate'; 
                    service4association.send(params); 
                } 
            } 
            private function openAssociation():void { 
                if(service4association.lastResult.items != null) 
                     createAndShow(service4association.lastResult.items.item); 

                else if(list != null){ 
                    PopUpManager.removePopUp(list); 
                    list = null; 
                    // 清空临时字符串 
                    temp = ''; 
                } 
            } 
            private function createAndShow(dp:Object):void { 
                // 每次打开联想框以前, 先清理缓存 
                if(list != null){ 
                    // 将联想框从PopUpManager中移除 
                    PopUpManager.removePopUp(list); 
                    // 清空联想框实例 
                    list = null; 
                } 

                list = new Association(); 
                //指定数据源 
                list.dataProvider = dp; 
                //获取鼠标坐标并赋值给list 
                list.x = txtAssociation.x + 219; 
                list.y = txtAssociation.y + 205; 
                //大小 
                list.minWidth = 400; 
                list.maxHeight = 270; 
                //注册list外鼠标按下和项目单击事件 
                list.addEventListener(FlexMouseEvent.MOUSE_DOWN_OUTSIDE, mouseDownOutsideHandler); 
                list.addEventListener(ListEvent.ITEM_CLICK, itemClik); 

                //弹出并显示list 
                PopUpManager.addPopUp(list, this, false); 
            } 
            private var associationResult:Object; 
            private function itemClik(event:ListEvent):void{ 
                associationResult = ArrayCollection(Association(event.target).dataProvider).getItemAt(event.rowIndex); 
                txtAssociation.text = associationResult.label; 
                //Alert.show(associationResult.data); 
                removePopUpIDisplay(Association(event.target)); 
            } 
            private function mouseDownOutsideHandler(event:MouseEvent):void{ 
                removePopUpIDisplay(Association(event.target)); 
            } 
            private function removePopUpIDisplay(obj:Association):void{ 
                // 清空临时字符串 
                temp = ''; 
                obj.removeEventListener(FlexMouseEvent.MOUSE_DOWN_OUTSIDE, mouseDownOutsideHandler); 
                PopUpManager.removePopUp(obj); 
            } 
            /**--------------------------联想-------------------------------**/