级联下拉菜单

需要引入jQuery

级联下拉菜单JS-casdrop.js：

var div_cascade;
//数据格式示例
/*
[
{"id":1,"name":"数码","pid":0},
{"id":2,"name":"手机","pid":1},
{"id":3,"name":"笔记本","pid":1},
{"id":4,"name":"iphone","pid":2},
{"id":5,"name":"食物","pid":0},
{"id":6,"name":"土豆","pid":5},
{"id":7,"name":"thinkpad","pid":3}
]
*/
function casdrop_init(datas,div_cascade_l,id)//datas JSON数据，div_cascade_l jQuery选择器，根节点的id
{
    div_cascade = div_cascade_l;
    createChildrenDropBoxById(datas,id);
}
function createChildrenDropBoxById(datas,id)
{
        var option_count = 0;
        var select_data;
        var select = $("<select></select>");
    for(var i = 0;i < datas.length;i++)
    {
        if(datas[i].pid == id)
        {
            if(option_count == 0)
            {
                select_data = datas[i];
            }
            select.append("<option>"+datas[i].name+"</option>");
            option_count++;
        }
    }
    select.appendTo(div_cascade).change(function(){
        var name = $(this).val();
        var data = getByName(datas,name);
        //var children = getChildrenById(datas,data.id);
        deleteSelectionAfterMe($(this));
        if(getChildrenById(datas,data.id).length != 0)
            createChildrenDropBoxById(datas,data.id);
    });
    if(select_data && getChildrenById(datas,select_data.id).length != 0)
        createChildrenDropBoxById(datas,select_data.id);                        
}
function deleteSelectionAfterMe($this)
{
    $this.nextAll(‘select‘).remove();
}
function getByName(datas,name)
{
    for(var i =0;i < datas.length;i++)
    {
        if(datas[i].name == name)
        {
            return datas[i];                
        }
    }
}
function getChildrenById(datas,id)
{
    var arr = [];
    for(var i =0;i < datas.length;i++)
    {
        if(datas[i].pid == id)
        {
            arr.push(datas[i]);
        }
    }
    return arr;
}

使用示例：

<div id=‘cascade‘ >
</div>
<script>
$.getJSON("ajaxtree",function(data){//AjaxCascadeDropBox
                casdrop_init(data,$(‘#cascade‘),0);
            })
</script>   

效果截图：