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下面的东西显示了在复杂的情况下, 怎样最好地在一个Element的旁边显示某个DIV。 当然,你可以滚动窗口,使这个按纽靠窗口的 左/上/右/下 的情况,观察菜单的弹出方位。 全部代码: 复制代码 代码如下:<table border=1 cellpadding=8 cellspacing=0> <tr><td>table1</td><td>table1</td></tr> <tr><td>table1</td><td> <div id=div1 style='position:absolute;background-color:wheat;padding:4px;'> div1 start <div id=div1button style='border:outset 2px;background-color:threedface;color:red;font-weight:bold;cursor:hand;padding:4px;'> ClickMe </div> div1 end </div> </td></tr> </table> <div style='height:100px'>-</div> <table border=1 cellpadding=8 cellspacing=0> <tr><td>table2</td><td>table2</td></tr> <tr><td>table2</td><td> <div id=div2 style='position:relative;left:24px;background-color:wheat;'> div2 start <div id=div2menu style='display:none;position:absolute;background-color:lightgrey;height:200px;width:120px;border:outset 1px;padding:4px'> div2menu<br> div2menu<br> div2menu<br> div2menu<br> div2menu<br> </div> div2 end </div> </td></tr> </table> <script language='jscript'> //get the position of a element ( by the scroll offset ) function LostinetWebGetScrollPostion(e) { var b=e.document.body; if(e==b)return {left:0,top:0}; with(e.getBoundingClientRect()) { return {left:b.scrollLeft+left,top:b.scrollTop+top}; } } //get the position of a element ( by the client offset ) function LostinetWebGetClientPosition(e) { var b=e.document.body; if(e==b)return {left:-b.scrollLeft,top:-b.scrollTop}; with(e.getBoundingClientRect()) { return {left:left-b.clientLeft,top:top-b.clientTop}; } } //get absolute or relative parent function LostinetWebGetStandParent(e) { for(var p=e.parentElement;p!=null;p=p.parentElement) { var sp=p.currentStyle.position; if(sp=='absolute'||sp=='relative') return p; } return e.document.body; } //calc the position of floate that relative to e function LostinetWebCalcPosition(floate,e) { var epos=LostinetWebGetScrollPostion(e); var spos=LostinetWebGetScrollPostion(LostinetWebGetStandParent(floate)); var s=LostinetWebGetStandParent(floate); return {left:epos.left-spos.left-s.clientLeft,top:epos.top-spos.top-s.clientTop}; } //get the best position to put the floate function LostinetWebAdjustMirror(floate,e,pos) { //c:Client,f:floate,e:e,p:floate's StandParent,m:Mirror var cw=e.document.body.clientWidth; var ch=e.document.body.clientHeight; var fw=floate.offsetWidth; var fh=floate.offsetHeight; var ew=e.offsetWidth; var eh=e.offsetHeight; var ecpos=LostinetWebGetClientPosition(e); var empos={left:ecpos.left+ew/2,top:ecpos.top+eh/2}; var pcpos=LostinetWebGetClientPosition(LostinetWebGetStandParent(floate)); var fcpos=LostinetWebGetClientPosition(floate); var fmpos={left:pcpos.left+pos.left+fw/2,top:pcpos.top+pos.top+fh/2}; //left<-->right if( (fmpos.left<empos.left) ? ((fmpos.left-fw/2<0)&&((empos.left*2-fmpos.left)+fw/2<=cw)) : ((fmpos.left+fw/2>cw)&&((empos.left*2-fmpos.left)-fw/2>=0)) ) fmpos.left=empos.left*2-fmpos.left; //top<-->bottom if( (fmpos.top<empos.top) ? ((fmpos.top-fh/2<0)&&((empos.top*2-fmpos.top)+fh/2<=ch)) : ((fmpos.top+fh/2>ch)&&((empos.top*2-fmpos.top)-fh/2>=0)) ) fmpos.top=empos.top*2-fmpos.top; pos.left=fmpos.left-pcpos.left-fw/2; pos.top=fmpos.top-pcpos.top-fh/2; } document.attachEvent('onclick',function f() { if(div1button.contains(event.srcElement))return; if(div2menu.contains(event.srcElement))return; div2menu.runtimeStyle.display='none'; }); function div1button.onclick() { div2menu.runtimeStyle.display='block'; var pos=LostinetWebCalcPosition(div2menu,div1button); pos.top+=div1button.offsetHeight; LostinetWebAdjustMirror(div2menu,div1button,pos); div2menu.runtimeStyle.left=pos.left; div2menu.runtimeStyle.top=pos.top; } </script> |
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