工具：电脑；浏览器；ultraedit软件；
操作步骤如下：
1、打开UE编辑器，新建一个空白的html文件和css文件；
2、在html文件中输入以下html代码；
3、在css文件中输入以下css代码；
4、编辑完成之后，选择格式为UTF8-无 BOM模式，保存文件；
5、在浏览器中打开此html文件，可以看到最终想要实现的遮住全屏效果。
遮罩层的CSS #mask { position: fixedleft: 0right: 0top: 0bottom: 0background: rgba(0, 0, 0, .3)z-index: 99999}在传统浏览器中，不支持rgba的写法。弹出div显示遮罩层的效果，想必大家都有见到过吧，下面有个示例，大家可以参考下代码如下:
//--------------------弹出层-------------------
//popDivId:弹出层div的ID
//dragDivId:用于拖动div的ID
//isShowMask:是否显示遮罩层
function
popDivShow(popDivId,
dragDivId,
isShowMask)
{
if
(isShowMask)
{
creatMask(popDivId)
}
var
oWins
=
document.getElementById(popDivId)
var
oWins_title
=
document.getElementById(dragDivId)
var
bDrag
=
false
var
disX
=
disY
=
0
oWins.style.display
=
"block"
oWins_title.onmousedown
=
function(event)
{
var
event
=
event
||
window.event
bDrag
=
true
disX
=
event.clientX
-
oWins.offsetLeft
disY
=
event.clientY
-
oWins.offsetTop
this.setCapture
&&
this.setCapture()
return
false
}
document.onmousemove
=
function(event)
{
if
(!bDrag)
return
var
event
=
event
||
window.event
var
iL
=
event.clientX
-
disX
var
iT
=
event.clientY
-
disY
var
maxL
=
document.documentElement.clientWidth
-
oWins.offsetWidth
var
maxT
=
document.documentElement.clientHeight
-
oWins.offsetHeight
iL
=
iL
<
0
?
0
:
iL
iL
=
iL
>
maxL
?
maxL
:
iL
iT
=
iT
<
0
?
0
:
iT
iT
=
iT
>
maxT
?
maxT
:
iT
oWins.style.marginTop
=
oWins.style.marginLeft
=
0
oWins.style.left
=
iL
+
"px"
oWins.style.top
=
iT
+
"px"
return
false
}
document.onmouseup
=
window.onblur
=
oWins_title.onlosecapture
=
function()
{
bDrag
=
false
oWins_title.releaseCapture
&&
oWins_title.releaseCapture()
}
}
//
隐藏弹出层
function
popDivHidden(popDivId)
{
var
oWins
=
document.getElementById(popDivId)
oWins.style.display
=
"none"
window.parent.document.body.removeChild(window.parent.document.getElementById("maskDiv"))
}
//
获取弹出层的zIndex
function
getZindex(popDivId)
{
var
popDiv
=
document.getElementById(popDivId)
var
popDivZindex
=
popDiv.style.zIndex
return
popDivZindex
}
//
创建遮罩层
function
creatMask(popDivId)
{
//
参数w为弹出页面的宽度,参数h为弹出页面的高度,参数s为弹出页面的路径
var
maskDiv
=
window.parent.document.createElement("div")
maskDiv.id
=
"maskDiv"
maskDiv.style.position
=
"fixed"
maskDiv.style.top
=
"0"
maskDiv.style.left
=
"0"
maskDiv.style.zIndex
=
getZindex(popDivId)
-
1
maskDiv.style.backgroundColor
=
"#333"
maskDiv.style.filter
=
"alpha(opacity=70)"
maskDiv.style.opacity
=
"0.7"
maskDiv.style.width
=
"100%"
maskDiv.style.height
=
(window.parent.document.body.scrollHeight
+
50)
+
"px"
window.parent.document.body.appendChild(maskDiv)
maskDiv.onmousedown
=
function()
{
window.parent.document.body.removeChild(window.parent.document.getElementById("maskDiv"))
}
}
