flex <param name="wmode" value="transparent">鼠标滚轮控制问题

1、网页嵌入flash后会覆盖html dom 元素，使用wmode为transparent时可以解决覆盖问题，因为此时它已经透明了。

2、transparent带来另一个问题，鼠标滚轮控制不了flash中的滚动条。

3、思路：通过js捕获鼠标滚轮事件，js调用flash方法传递滚轮->flash组件调用滚轮事件传递的参数。

eg：使用js捕获鼠标滚轮事件后控制flex dataGrid组件的滚动条

js代码

function addMouseWheelListener(){
var flash = thisMovie("videoControl");
var ua = navigator.userAgent;
if(ua.indexOf("Firefox") > -1){
flash.addEventListener('DOMMouseScroll',onWheelZoom,false);
}else if(ua.indexOf("MSIE") == -1){
flash.addEventListener('mousewheel',onWheelZoom,false);
}else{
flash.attachEvent('onmousewheel',onWheelZoom);
}
}

function onWheelZoom(event){
var app = window.document["videoControl"];
if (app) {
var o= {delta: event.wheelDelta}
thisMovie("videoControl").jsWheelZoom(o);
}
}

flex代码

在初始化时候注册js 监听方法和回调方法 ，方法如下

ExternalInterface.addCallback("jsWheelZoom", jsWheelZoom);

ExternalInterface.call("addMouseWheelListener");

private function jsWheelZoom(o:Object):void
{
var e:MouseEvent = new MouseEvent(MouseEvent.MOUSE_WHEEL,true);
e.delta = -(o.delta);
onWheelZoom(e);
}
private function onWheelZoom(e:MouseEvent):void
{
if(e.delta>2)
{
this.camera.verticalScrollPosition += 1;
if(this.camera.verticalScrollPosition > this.camera.maxVerticalScrollPosition)
{
this.camera.verticalScrollPosition = this.camera.maxVerticalScrollPosition
}
}
if(e.delta<-2)
{
this.camera.verticalScrollPosition -= 1;
if(this.camera.verticalScrollPosition < 0)
{
this.camera.verticalScrollPosition = 0;
}
}
}