JavaScript实现iframe双向拉伸拖动的三种方案

iframe分栏拖动布局方案

该方案旨在实现左侧iframe显示树形目录，右侧iframe显示主页内容，并通过鼠标拖动操作同时调整这两个iframe的宽高尺寸。

作者表示当前实现仍有改进空间，期待有更优化的解决方案。

具体交互方式为：当鼠标指针移动到两个iframe之间的分隔区域时，支持水平方向的拖动调整，同时也支持纵向拖动以控制高度。

该实现存在性能缺陷：与CSDN页面在鼠标释放后才更新尺寸以节省CPU资源不同，此方案是实时计算并更新大小，导致运行速度较慢。作者因觉得未涉及复杂技术且性能不佳，已放弃进一步优化。

实现拖动的关键技巧在于使用CSS属性 filter:alpha(opacity=0)，使用于接收鼠标事件的透明层不可见。

<html>
<script language="javascript">
var mouseX = 0;
var mouseY = 0;
var w=5;
function divonmousemove(){
obj1=document.getElementById("a");
obj2=document.getElementById("b");
obj12=document.getElementById("ab");
if (mouseX!==event.x && mouseY!==event.y)obj12.style.cursor='se-resize';
else if (mouseX!==event.x)obj12.style.cursor='e-resize';
else if (mouseY!==event.y)obj12.style.cursor='s-resize';
else obj12.style.cursor='';
if (event.button==1){
obj1.style.width=parseInt(obj1.offsetWidth)+(event.x - mouseX);
mouseX=event.x;
obj1.style.height=parseInt(obj1.offsetHeight)+(event.y - mouseY);
mouseY= event.y;
obj12.style.width=108;
obj12.style.left=obj1.offsetWidth-obj12.offsetWidth/2;
obj12.style.height=obj1.clientHeight;
obj2.style.height=obj1.clientHeight;
obj2.style.left=obj1.clientWidth+w;
obj2.style.width=screen.width-obj1.offsetWidth-w;
 }} 
function divonmousedown(){
mouseX = event.x;
mouseY = event.y;
 } 
function divonmouseup(){
obj12.style.left=obj1.offsetWidth;
obj12.style.width=w;
mouseX = 0;
mouseY = 0;}
</script>
<body style='margin:0'>
<iframe zindex=1 id="a" src="https://www.jb51.net/Tree/tree.htm" style="width:200;height:610;position:absolute;z-index:9 "></iframe>
<div zindex=0 id='ab' onmousemove='divonmousemove();' onmouseleave='document.getElementById("ab").style.cursor='';'
onmousedown='divonmousedown();' onmouseup='divonmouseup();'
style='filter:alpha(opacity=0);width:5;height:799;background:#aaffaa;position:absolute;left:200;z-index:100' title='按下鼠标拖动大小'></div>
<iframe zindex=1 id="b" name="ContentFrame" src="https://www.jb51.net/index.htm" style="width:799;height:612;position:absolute;left:205;z-index:10"></iframe>
</body>
</html>

基于表格布局的优化实现

修改一：

<script language="javascript">
var isResizing=false;
function Resize_mousedown(event,obj){
obj.mouseDownX=event.clientX;
obj.leftTdW=obj.previousSibling.offsetWidth;
obj.setCapture();
isResizing=true;
}
function Resize_mousemove(event,obj){
if(!isResizing) return ;
var newWidth=obj.leftTdW*1+event.clientX*1-obj.mouseDownX;
if(newWidth>0) obj.previousSibling.style.width = newWidth;
else obj.previousSibling.style.width=1;
}
function Resize_mouseup(event,obj){
if(!isResizing) return;
obj.releaseCapture();
isResizing=false;
}
< /script>
< body style='margin:0' >
< table style="width:100%;height:100%;" border=0 cellspacing=0 cellpadding=0px >
< tr>
< td style="width:150px;">
< iframe zindex=1 id="a" src="https://www.jb51.net/Tree/tree.htm" style="width:100%;height:100%;z-index:9 "></iframe>
< /td>
< td style="width:2px;cursor:e-resize;background-color:#cccccc;" onmousedown="Resize_mousedown(event,this);"
onmouseup="Resize_mouseup(event,this);" onmousemove="Resize_mousemove(event,this);">
< /td>
< td>
< iframe zindex=1 id="b" name="ContentFrame" src="https://www.jb51.net/index.htm" style="width:100%;height:100%;z-index:10"></iframe>
< /td>
< /tr>
< /table>
< /body>

带折叠功能的增强版代码

修改二：

<script language="javascript">
var isResizing=false;
function Resize_mousedown(event,obj){
obj.mouseDownX=event.clientX;
obj.leftTdW=obj.previousSibling.offsetWidth;
obj.setCapture();
isResizing=true;
}
function Resize_mousemove(event,obj){
if(!isResizing) return ;
var newWidth=obj.leftTdW*1+event.clientX*1-obj.mouseDownX;
if(newWidth>0) obj.previousSibling.style.width = newWidth;
else obj.previousSibling.style.width=1;
}
function Resize_mouseup(event,obj){
if(!isResizing) return;
obj.releaseCapture();
isResizing=false;
}
function Resize_setDefault(event,obj){
if(obj.innerText=="<") {
obj.parentNode.previousSibling.style.width=1;
obj.innerText=">";
}
else{
obj.parentNode.previousSibling.style.width=150;
obj.innerText="<";
}
event.cancelBubble=true;
}
< /script>
< body style='margin:0' >
< table style="width:100%;height:100%;" border=0 cellspacing=0 cellpadding=0px >
< tr>
< td style="width:150px;" >
< iframe zindex=1 id="a" src="https://www.jb51.net/Tree/tree.htm" style="width:100%;height:100%;z-index:9 "></iframe>
< /td>
< td style="width:3px;cursor:e-resize;background-color:#cccccc;" align="center" valign="middle"
onmousedown="Resize_mousedown(event,this);" onmouseup="Resize_mouseup(event,this);" onmousemove="Resize_mousemove(event,this);">
<font style="size:3px;background-color:#eeeeee;cursor:pointer;" onmousedown="Resize_setDefault(event,this);"><</font>
< /td>
< td>
< iframe zindex=1 id="b" name="ContentFrame" src="https://www.jb51.net/index.htm" style="width:100%;height:100%;z-index:10"></iframe>
< /td>
< /tr>
< /table>
< /body>