根据参数显示类别（三级联动，需要JSON数据）-创新互联

Scripts/Category.js

调用方法：

$(function () {
    BindCategory();
//默认绑定文本框中的值    BindCategoryData($("#txtCategoryId").val());
})

绑定三级联动（详情见：http://www.cnblogs.com/haozhenjie819/p/3887279.html）

function BindCategory() {
var $txtCategory = $("#txtCategoryId");
var _selectId = ["selBigClass", "selSmallClass", "selThreeClass"];
for (var i = 0; i < _selectId.length; i++) {
var select = document.createElement("select");
        select.id= _selectId[i];
        select.name= _selectId[i];
        $txtCategory.parent().append(select);
    }
var $selBigClass = $("#selBigClass");
var $selSmallClass = $("#selSmallClass");
var $selThreeClass = $("#selThreeClass");
    $selSmallClass.hide();
    $selThreeClass.hide();
    $.getJSON("/Scripts/CategoryJson.js", function (json) {
var html = ['请选择大类'];
for (var key in json) {
if (json[key].pid == 0) {
                html.push('' + json[key].name + '');
            }
        }
//第一级类别        $selBigClass.empty().append(html.join('')).change(function () {
            $txtCategory.val(this.value);
            $selThreeClass.hide();
            $selSmallClass.show();
var html = ['请选择小类'];
for (var data in json) {
if (json[data].pid == $("#selBigClass").val()) {
                    html.push('' + json[data].name + '');
                }
            }
//第二级类别            $selSmallClass.empty().append(html.join('')).change(function () {
                $txtCategory.val(this.value);               
                $selThreeClass.show();
var html = ['请选择小类'];
for (var data in json) {
if (json[data].pid == $selSmallClass.val()) {
                        html.push('' + json[data].name + '');
                    }
                }
//第三级类别                $selThreeClass.empty().append(html.join('')).change(function () {
                    $txtCategory.val(this.value);
                });
//如果不存在第三级类别则隐藏第三级类别控件  if ($selThreeClass.get(0).options.length <= 1) {
                    $selThreeClass.hide();
return false;
                }
            });
//如果不存在第二级类别则隐藏第二级类别控件 if ($selSmallClass.get(0).options.length <= 1) {
                $selSmallClass.hide();
return false;
            }
           
        });
    });
};

根据参数显示默认值

var setBigClassTime;
//绑定数据function BindCategoryData(CategoryId) {
if (document.getElementById("selBigClass") == null || document.getElementById("selBigClass").length <= 0)
        setBigClassTime= setTimeout("BindCategoryData('" + CategoryId + "')", 200);
else
        clearTimeout(setBigClassTime);
    $.getJSON('/Scripts/CategoryJson.js', function (json) {
for (var key in json) {
if (json[key].id == CategoryId) {
                json[key].id= CategoryId;
var str = json[key].itemvalue;
var _p = str.split("|")[2];
var _c = json[key].pid;
if (_p == _c) {
if (_p != "") {
                        $("#selBigClass").val(_p).change();
                        $("#selSmallClass").val(CategoryId);
                    }
else {
                        $("#selBigClass").val(CategoryId);
                    }
                }
else {
                    $("#selBigClass").val(_p).change();
                    $("#selSmallClass").val(_c).change();
                    $("#selThreeClass").val(CategoryId).change();
                }
            }
        }
    });
}

Scripts/CategoryJson.js（如何生成json数据详见：http://www.cnblogs.com/haozhenjie819/p/3601676.html）

[{ "id": 31, "name": "u65b0u95fbu4e2du5fc3", "pid": 0, "itemvalue": "|0|" },
{"id": 59, "name": "u52a0u76dfu5408u4f5c", "pid": 0, "itemvalue": "|0|" },
{"id": 65, "name": "u4ea7u54c1u670du52a1", "pid": 0, "itemvalue": "|0|" },



{"id": 60, "name": "u52a0u76dfu987bu77e5", "pid": 59, "itemvalue": "|0|59|" },
{"id": 61, "name": "u52a0u76dfu6d41u7a0b", "pid": 59, "itemvalue": "|0|59|" },
{"id": 62, "name": "u52a0u76dfu533au57df", "pid": 59, "itemvalue": "|0|59|" },



{"id": 70, "name": "u63a8u8350u670du52a1", "pid": 65, "itemvalue": "|0|65|" },
{"id": 71, "name": "u8ba1u8d39u65b9u5f0f", "pid": 65, "itemvalue": "|0|65|" },
{"id": 72, "name": "u7528u6237u987bu77e5", "pid": 65, "itemvalue": "|0|65|" },
{"id": 73, "name": "u7981u5bc4u8303u56f4", "pid": 65, "itemvalue": "|0|65|" },
{"id": 75, "name": "u666eu901au5febu9012", "pid": 70, "itemvalue": "|0|65|70|" },
{"id": 76, "name": "u7279u79cdu5febu4ef6", "pid": 70, "itemvalue": "|0|65|70|" },
{"id": 77, "name": "u9650u65f6u6d3eu9001", "pid": 70, "itemvalue": "|0|65|70|" },
{"id": 78, "name": "u4ee3u6536u8d37u6b3e", "pid": 70, "itemvalue": "|0|65|70|" },
{"id": 79, "name": "u4fddu4ef7u670du52a1", "pid": 70, "itemvalue": "|0|65|70|" }, 
{"id": 80, "name": "u4ee3u7b7eu56deu5355", "pid": 70, "itemvalue": "|0|65|70|"}]

web页面（给hidden赋值，类别编号为75）

        
     
 
 
  
新闻类别：
  
 
 
    
   
      

效果图

涉及的知识点：【JavaScript split() 方法】返回值是一个字符串数组。