javascript实现的树型下拉框改进版_导航菜单

2019年10月1日 16:59:20js教程评论747 views阅读模式

原理是先顺序加载根节点，在加载每个根节点后，再遍历每个数组，看有没有以这个根节点为父节点的数组，如果有，就加载到下拉框，然后再递归看有没有以这个节点为父结点的数组，如果有，再加载到下拉框，以此类推...

代码如下：

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
<title> javascript树型菜单 author:sclsch@188.com</title> 
<meta name="generator" content="editplus" /> 
<meta name="author" content="" /> 
<meta name="keywords" content="" /> 
<meta name="description" content="" /> 
<script type="text/javascript"> 
var data =new Array(); 
data[0]= {id:'0',pid:'1',text:'河北'}; 
data[1]= {id:'1',pid:'-1',text:'中国'}; 
data[2]= {id:'2',pid:'6',text:'莫斯科'}; 
data[3]= {id:'3',pid:'0',text:'邯郸'}; 
data[4]= {id:'4',pid:'0',text:'石家庄'}; 
data[5]= {id:'5',pid:'3',text:'邯郸县'}; 
data[6]= {id:'6',pid:'-1',text:'俄罗斯'}; 
data[7]= {id:'7',pid:'5',text:'孙程亮 sclsch@188.com'}; 
function TreeSelector(item,data,rootId){ 
this._data = data; 
this._item = item; 
this._rootId = rootId; 
} 
TreeSelector.prototype.createTree = function(){ 
var len =this._data.length; 
for( var i= 0;i<len;i++){ 
if ( this._data[i].pid == this._rootId){ 
this._item.options.add(new Option(".."+this._data[i].text,this._data[i].id)); 
for(var j=0;j<len;j++){ 
this.createSubOption(len,this._data[i],this._data[j]); 
} 
} 
} 
} 
TreeSelector.prototype.createSubOption = function(len,current,next){ 
var blank = ".."; 
if ( next.pid == current.id){ 
intLevel =0; 
var intlvl =this.getLevel(this._data,this._rootId,current); 
for(a=0;a<intlvl;a++) 
blank += ".."; 
blank += "├-"; 
this._item.options.add(new Option(blank + next.text,next.id)); 
for(var j=0;j<len;j++){ 
this.createSubOption(len,next,this._data[j]); 
} 
} 
} 
TreeSelector.prototype.getLevel = function(datasources,topId,currentitem){ 
var pid =currentitem.pid; 
if( pid !=topId) 
{ 
for(var i =0 ;i<datasources.length;i++) 
{ 
if( datasources[i].id == pid) 
{ 
intLevel ++; 
this.getLevel(datasources,topId,datasources[i]); 
} 
} 
} 
return intLevel; 
} 
//www.jb51.net 脚本之家 
</script> 
</head> 
<body> 
<select id="myselect"> 
</select> 
<script language=javascript type="text/javascript"> 
var ts = new TreeSelector(document.getElementById("myselect"),data,-1); 
ts.createTree(); 
</script> 
</body> 
</html>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]