使用AjaxPro开发四级无刷新联动下拉框

【 tulaoshi.com - Web开发 】

　　开发环境 VS.NET 2005    C#    Oracle   AjaxPro  

　　最近忙没时间详细解释，先把通用的源码贴出自己看。

　　出于对性能的考虑，把省市两级写成JS数组，把县区（镇）两级写在 Oracle 里。通过 JS 触发 C# 去读取数据库，然后将数据回传给 JS ，再绑定显示。

　　操作 select 采用更通用的 createElement() 而没有使用 options.add()

　　%@ Page Language="C#" AutoEventWireup="true" CodeFile="Area.aspx.cs" Inherits="Area" %

　　!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 runat="server"
　　    title地区/title
　　/head
　　body
　　    form id="form1" runat="server"
　　        table
　　            tr
　　                td
　　                    select id="SF"
　　                        option selected="selected"—请选择—/option
　　                    /select
　　                /td
　　                td
　　                    select id="CS"
　　                        option selected="selected"—请选择—/option
　　                    /select
　　                /td
　　                td
　　                    select id="Xian"
　　                        option selected="selected"—请选择—/option
　　                    /select
　　                /td
　　                td
　　                    select id="Zhen"
　　                        option selected="selected"—请选择—/option
　　                    /select
　　                /td
　　            /tr
　　        /table

　　script type="text/javascript"
　　var aDQ=new Array();
　　aDQ[0]=["11","北京","0","bj"];
　　aDQ[1]=["12","天津","0","tj"];
　　aDQ[2]=["13","河北","0","hb"];
　　aDQ[3]=["14","山西","0","shang"];
　　aDQ[4]=["15","内蒙古","0","nmg"];
　　aDQ[5]=["21","辽宁","0","ln"];
　　aDQ[6]=["22","吉林","0","jl"];
　　aDQ[7]=["23","黑龙江","0","hlj"];
　　aDQ[8]=["31","上海","0","sh"];
　　aDQ[9]=["32","江苏","0","js"];
　　aDQ[10]=["33","浙江","0","zhej"];
　　aDQ[11]=["34","安徽","0","ah"];
　　aDQ[12]=["35","福建","0","fj"];
　　aDQ[13]=["36","江西","0","jw"];
　　aDQ[14]=["37","山东","0","sd"];
　　aDQ[15]=["41","河南","0","he"];
　　aDQ[16]=["42","湖北","0","hu"];
　　aDQ[17]=["43","湖南","0","hn"];
　　aDQ[18]=["44","广东","0","gd"];
　　aDQ[19]=["45","广西","0","gx"];
　　aDQ[20]=["46","海南","0","hain"];
　　aDQ[21]=["50","重庆","0","cq"];
　　aDQ[22]=["51","四川","0","sc"];
　　aDQ[23]=["52","贵州","0","gui"];
　　aDQ[24]=["53","云南","0","yn"];
　　aDQ[25]=["54","西藏","0","wc"];
　　aDQ[26]=["61","陕西","0","shangx"];
　　aDQ[27]=["62","甘肃","0","gs"];
　　aDQ[28]=["63","青海","0","qh"];
　　aDQ[29]=["64","宁夏","0","nx"];
　　aDQ[30]=["65","新疆","0","xj"];
　　aDQ[31]=["71","台湾","0","tw"];
　　aDQ[32]=["81","香港","0","xg"];
　　aDQ[33]=["82","澳门","0","am"];
　　aDQ[34]=["1101","北京城区","11","bjcq"];
　　aDQ[35]=["1102","北京县区","11","bjxq"];
　　aDQ[36]=["1201","天津城区","12","tjcq"];
　　aDQ[37]=["1202","天津县区","12","tjxq"];
　　aDQ[38]=["1301","石家庄","13","sjz"];
　　aDQ[39]=["1302","唐山","13","hbts"];
　　aDQ[40]=["1303","秦皇岛","13","qhd"];
　　aDQ[41]=["1304","邯郸","13","hd"];
　　aDQ[42]=["1305","邢台","13","hbxt"];
　　aDQ[43]=["1306","保定","13","bd"];
　　aDQ[44]=["1307","张家口","13","zjk"];
　　aDQ[45]=["1308","承德","13","cd"];
　　aDQ[46]=["1309","沧州","13","hbcz"];
　　aDQ[47]=["1310","廊坊","13","lf"];
　　aDQ[48]=["1311","衡水","13","hbhs"];
　　aDQ[49]=["1401","太原","14","ty"];
　　aDQ[50]=["1402","大同","14","dt"];
　　aDQ[51]=["1403","阳泉","14","yq"];
　　aDQ[52]=["1404","长治","14","swcz"];
　　aDQ[53]=["1405","晋城","14","swjc"];
　　aDQ[54]=["1406","朔州","14","swsz"];
　　aDQ[55]=["1501","呼和浩特","15","hhht"];
　　aDQ[56]=["1502","包头","15","bt"];
　　aDQ[57]=["1503","乌海","15","nmgwh"];
　　aDQ[58]=["1504","赤峰","15","cf"];
　　aDQ[59]=["1521","呼伦贝尔盟","15","hlbem"];
　　aDQ[60]=["1522","兴安盟","15","xam"];
　　aDQ[61]=["1523","哲里木盟","15","zlmm"];
　　aDQ[62]=["1525","锡林郭勒盟","15","wlglm"];
　　aDQ[63]=["1526","乌兰察布盟","15","wlcbm"];
　　aDQ[64]=["1527","鄂尔多斯","15","eeds"];
　　aDQ[65]=["1528","巴彦淖尔盟","15","bynem"];
　　aDQ[66]=["1529","阿拉善盟","15","alsm"];
　　aDQ[67]=["2101","沈阳","21","lnsy"];
　　aDQ[68]=["2102","大连","21","dl"];
　　aDQ[69]=["2103","鞍山","21","as"];
　　aDQ[70]=["2104","抚顺","21","lnfs"];
　　aDQ[71]=["2105","本溪","21","bx"];
　　aDQ[72]=["2106","丹东","21","dd"];
　　aDQ[73]=["2107","锦州","21","jz"];
　　aDQ[74]=["2108","营口","21","yk"];
　　aDQ[75]=["2109","阜新","21","fx"];
　　aDQ[76]=["2110","辽阳","21","lnly"];
　　aDQ[77]=["2111","盘锦","21","pj"];
　　aDQ[78]=["2112","铁岭","21","lntl"];
　　aDQ[79]=["2113","朝阳","21","cy"];
　　aDQ[80]=["2114","葫芦岛","21","hld"];
　　aDQ[81]=["2201","长春","22","cc"];
　　aDQ[82]=["2202","吉林","22","jljl"];
　　aDQ[83]=["2203","四平","22","sp"];
　　aDQ[84]=["2204","辽源","22","jlly"];
　　aDQ[85]=["2205","通化","22","th"];
　　aDQ[86]=["2206","白山","22","bs"];
　　aDQ[87]=["2207","松原","22","jlsy"];
　　aDQ[88]=["2208","白城","22","bc"];
　　aDQ[89]=["2224","延边","22","jlyb"];
　　aDQ[90]=["2301","哈尔滨","23","heb"];
　　aDQ[91]=["2302","齐齐哈尔","23","qqhe"];
　　aDQ[92]=["2303","鸡西","23","hljjw"];
　　aDQ[93]=["2304","鹤岗","23","hg"];
　　aDQ[94]=["2305","双鸭山","23","sys"];
　　aDQ[95]=["2306","大庆","23","dq"];
　　aDQ[96]=["2307","伊春","23","hljyc"];
　　aDQ[97]=["2308","佳木斯","23","jms"];
　　aDQ[98]=["2309","七台河","23","qth"];
　　aDQ[99]=["2310","牡丹江","23","mdj"];
　　aDQ[100]=["2311","黑河","23","hh"];
　　aDQ[101]=["3101","上海市区","31","shsq"];
　　aDQ[102]=["3102","上海县区","31","shxq"];
　　aDQ[103]=["3201","南京","32","nj"];
　　aDQ[104]=["3202","无锡","32","ww"];
　　aDQ[105]=["3203","徐州","32","xz"];
　　aDQ[106]=["3204","常州","32","jscz"];
　　aDQ[107]=["3205","苏州","32","shu"];
　　aDQ[108]=["3206","南通","32","nt"];
　　aDQ[109]=["3207","连云港","32","lyg"];
　　aDQ[110]=["3208","淮安","32","ha"];
　　aDQ[111]=["3209","盐城","32","jsyc"];
　　aDQ[112]=["3210","扬州","32","yz"];
　　aDQ[113]=["3211","镇江","32","jszj"];
　　aDQ[114]=["3212","泰州","32","tz"];
　　aDQ[115]=["3213","宿迁","32","sq"];
　　aDQ[116]=["3301","杭州","33","han"];
　　aDQ[117]=["3302","宁波","33","nb"];
　　aDQ[118]=["3303","温州","33","zjwz"];
　　aDQ[119]=["3304","嘉兴","33","jx"];
　　aDQ[120]=["3305","湖州","33","zjhz"];
　　aDQ[121]=["3306","绍兴","33","sx"];
　　aDQ[122]=["3307","金华","33","jh"];
　　aDQ[123]=["3308","衢州","33","zjqz"];
　　aDQ[124]=["3309","舟山","33","zjzs"];
　　aDQ[125]=["3310","台州","33","zjtz"];
　　aDQ[126]=["3311","义乌","33","yw"];
　　aDQ[127]=["3325","丽水","33","zjls"];
　　aDQ[128]=["3401","合肥","34","hf"];
　　aDQ[129]=["3402","芜湖","34","wh"];
　　aDQ[130]=["3403","蚌埠","34","bb"];
　　aDQ[131]=["3404","淮南","34","hnx"];
　　aDQ[132]=["3405","马鞍山","34","mas"];
　　aDQ[133]=["3406","淮北","34","huib"];
　　aDQ[134]=["3407","铜陵","34","tl"];
　　aDQ[135]=["3408","安庆","34","aq"];
　　aDQ[136]=["3410","黄山","34","hs"];
　　aDQ[137]=["3411","滁州","34","ahcz"];
　　aDQ[138]=["3412","阜阳","34","fy"];
　　aDQ[139]=["3413","宿州","34","ahsz"];
　　aDQ[140]=["3416","毫州","34","ahhz"];
　　aDQ[141]=["51011117","池州","34",""];
　　aDQ[142]=["51011118","六安","34",""];
　　aDQ[143]=["51011119","宣城 ","34",""];
　　aDQ[144]=["3501","福州","35","fz"];
　　aDQ[145]=["3502","厦门","35","xm"];
　　aDQ[146]=["3503","莆田","35","pt"];
　　aDQ[147]=["3504","三明","35","sm"];
　　aDQ[148]=["3505","泉州","35","qz"];
　　aDQ[149]=["3506","漳州","35","fzz"];
　　aDQ[150]=["3507","南平","35","np"];
　　aDQ[151]=["3508","龙岩","35","fjly"];
　　aDQ[152]=["3509","宁德","35","fjnd"];
　　aDQ[153]=["3601","南昌","36","jwnc"];
　　aDQ[154]=["3602","景德镇","36","jdz"];
　　aDQ[155]=["3603","萍乡","36","px"];
　　aDQ[156]=["3604","九江","36","jj"];
　　aDQ[157]=["3605","新余","36","xy"];
　　aDQ[158]=["3606","鹰潭","36","jwyt"];
　　aDQ[159]=["3607","赣州","36","jwgz"];
　　aDQ[160]=["3701","济南","37","jn"];
　　aDQ[161]=["3702","青岛","37","qd"];
　　aDQ[162]=["3703","淄博","37","zb"];
　　aDQ[163]=["3704","枣庄","37","sdzz"];
　　aDQ[164]=["3705","东营","37","sddy"];
　　aDQ[165]=["3706","烟台","37","yt"];
　　aDQ[166]=["3707","潍坊","37","wf"];
　　aDQ[167]=["3708","济宁","37","sdjn"];
　　aDQ[168]=["3709","泰安","37","ta"];
　　aDQ[169]=["3710","威海","37","sdwh"];
　　aDQ[170]=["3711","日照","37","rz"];
　　aDQ[171]=["3712","莱芜","37","lw"];
　　aDQ[172]=["3713","临沂","37","ly"];
　　aDQ[173]=["3714","德州","37","sddz"];
　　aDQ[174]=["3715","聊城","37","lc"];
　　aDQ[175]=["4101","郑州","41","zhen"];
　　aDQ[176]=["4102","开封","41","kf"];
　　aDQ[177]=["4103","洛阳","41","hnly"];
　　aDQ[178]=["4104","平顶山","41","pds"];
　　aDQ[179]=["4105","安阳","41","ay"];
　　aDQ[180]=["4106","鹤壁","41","hebi"];
　　aDQ[181]=["4107","新乡","41","xx"];
　　aDQ[182]=["4108","焦作","41","hnjz"];
　　aDQ[183]=["4109","濮阳","41","zy"];
　　aDQ[184]=["4110","许昌","41","xc"];
　　aDQ[185]=["4111","漯河","41","zhe"];
　　aDQ[186]=["4112","三门峡","41","smx"];
　　aDQ[187]=["4113","南阳","41","ny"];
　　aDQ[188]=["4114","商丘","41","hnsq"];
　　aDQ[189]=["4115","信阳","41","hnxy"];
　　aDQ[190]=["4201","武汉","42","hbwh"];
　　aDQ[191]=["4202","黄石","42","hhs"];
　　aDQ[192]=["4203","十堰","42","sy"];
　　aDQ[193]=["4205","宜昌","42","hbyc"];
　　aDQ[194]=["4206","襄樊","42","xf"];
　　aDQ[195]=["4207","鄂州","42","ez"];
　　aDQ[196]=["4208","荆门","42","hbjm"];
　　aDQ[197]=["4209","孝感","42","hbxg"];
　　aDQ[198]=["4210","荆州","42","hbjz"];
　　aDQ[199]=["4211","黄冈","42","hbhg"];
　　aDQ[200]=["4212","咸宁","42","xn"];
　　aDQ[201]=["4228","恩施","42","es"];
　　aDQ[202]=["4301","长沙","43","cs"];
　　aDQ[203]=["4302","株洲","43","hnzz"];
　　aDQ[204]=["4303","湘潭","43","xt"];
　　aDQ[205]=["4304","衡阳","43","hnhy"];
　　aDQ[206]=["4305","邵阳","43","shao"];
　　aDQ[207]=["4306","岳阳","43","yy"];
　　aDQ[208]=["4307","常德","43","hncd"];
　　aDQ[209]=["4308","张家界","43","zjj"];
　　aDQ[210]=["4309","益阳","43","hnyy"];
　　aDQ[211]=["4310","郴州","43","hncz"];
　　aDQ[212]=["4311","永州","43","hnyz"];
　　aDQ[213]=["4312","怀化","43","hnhh"];
　　aDQ[214]=["4331","湘西","43","xw"];
　　aDQ[215]=["4401","广州","44","gz"];
　　aDQ[216]=["4402","韶关","44","sg"];
　　aDQ[217]=["4403","深圳","44","sz"];
　　aDQ[218]=["4404","珠海","44","zh"];
　　aDQ[219]=["4405","汕头","44","st"];
　　aDQ[220]=["4406","佛山","44","fs"];
　　aDQ[221]=["4407","江门","44","jm"];
　　aDQ[222]=["4408","湛江","44","zj"];
　　aDQ[223]=["4409","茂名","44","mm"];
　　aDQ[224]=["4412","肇庆","44","zq"];
　　aDQ[225]=["4413","惠州","44","hz"];
　　aDQ[226]=["4414","梅州","44","mz"];
　　aDQ[227]=["4415","汕尾","44","shanw"];
　　aDQ[228]=["4416","河源","44","hy"];
　　aDQ[229]=["4417","阳江","44","yj"];
　　aDQ[230]=["4418","清远","44","qy"];
　　aDQ[231]=["4419","东莞","44","dz"];
　　aDQ[232]=["4420","中山","44","zs"];
　　aDQ[233]=["4451","潮州","44","cz"];
　　aDQ[234]=["4452","揭阳","44","jy"];
　　aDQ[235]=["4453","云浮","44","yf"];
　　aDQ[236]=["4501","南宁","45","nn"];
　　aDQ[237]=["4502","柳州","45","lz"];
　　aDQ[238]=["4503","桂林","45","gwgl"];
　　aDQ[239]=["4504","梧州","45","gwwz"];
　　aDQ[240]=["4505","北海","45","bh"];
　　aDQ[241]=["4506","防城港","45","fcg"];
　　aDQ[242]=["4507","钦州","45","gqz"];
　　aDQ[243]=["4508","贵港","45","gg"];
　　aDQ[244]=["4509","玉林","45","yl"];
　　aDQ[245]=["4601","海口","46","hk"];
　　aDQ[246]=["4602","三亚","46","hnsy"];
　　aDQ[247]=["5002","重庆县区","50","zqxq"];
　　aDQ[248]=["5003","重庆城区","50","zqcq"];
　　aDQ[249]=["5101","成都","51","sccd"];
　　aDQ[250]=["5103","自贡","51","zg"];
　　aDQ[251]=["5104","攀枝花","51","pzh"];
　　aDQ[252]=["5105","泸州","51","sczz"];
　　aDQ[253]=["5106","德阳","51","dy"];
　　aDQ[254]=["5107","绵阳","51","my"];
　　aDQ[255]=["5108","广元","51","gy"];
　　aDQ[256]=["5109","遂宁","51","sn"];
　　aDQ[257]=["5110","内江","51","scnj"];
　　aDQ[258]=["5111","乐山","51","ls"];
　　aDQ[259]=["5113","南充","51","nc"];
　　aDQ[260]=["5115","宜宾","51","yb"];
　　aDQ[261]=["5116","广安","51","ga"];
　　aDQ[262]=["5130","达州","51","scdz"];
　　aDQ[263]=["5132","阿坝","51","ab"];
　　aDQ[264]=["5133","甘孜","51","scgz"];
　　aDQ[265]=["5134","凉山","51","scls"];
　　aDQ[266]=["5201","贵阳","52","gzgy"];
　　aDQ[267]=["5202","六盘水","52","lps"];
　　aDQ[268]=["5203","遵义","52","gzzy"];
　　aDQ[269]=["5223","黔西南","52","qwn"];
　　aDQ[270]=["5226","黔东南","52","qdn"];
　　aDQ[271]=["5227","黔南","52","qn"];
　　aDQ[272]=["5301","昆明","53","km"];
　　aDQ[273]=["5303","曲靖","53","qj"];
　　aDQ[274]=["5304","玉溪","53","yx"];
　　aDQ[275]=["5323","楚雄","53","cx"];
　　aDQ[276]=["5325","红河","53","ynhh"];
　　aDQ[277]=["5326","文山","53","ws"];
　　aDQ[278]=["5328","西双版纳","53","wsbn"];
　　aDQ[279]=["5329","大理","53","yndl"];
　　aDQ[280]=["5331","德宏","53","dh"];
　　aDQ[281]=["5333","怒江","53","nuj"];
　　aDQ[282]=["5334","迪庆","53","yndq"];
　　aDQ[283]=["51010963","丽江市","53","ljs"];
　　aDQ[284]=["51012663","保山","53",""];
　　aDQ[285]=["5401","拉萨","54","wcls"];
　　aDQ[286]=["6101","西安","61","wa"];
　　aDQ[287]=["6102","铜川","61","tc"];
　　aDQ[288]=["6103","宝鸡","61","swbj"];
　　aDQ[289]=["6104","咸阳","61","swxy"];
　　aDQ[290]=["6105","渭南","61","swwn"];
　　aDQ[291]=["6106","延安","61","ya"];
　　aDQ[292]=["6107","汉中","61","swhz"];
　　aDQ[293]=["6201","兰州","62","gslz"];
　　aDQ[294]=["6202","嘉峪关","62","jyg"];
　　aDQ[295]=["6203","金昌","62","jc"];
　　aDQ[296]=["6204","白银","62","by"];
　　aDQ[297]=["6205","天水","62","ts"];
　　aDQ[298]=["6229","临夏","62","lx"];
　　aDQ[299]=["6230","甘南","62","gn"];
　　aDQ[300]=["6301","西宁","63","wn"];
　　aDQ[301]=["6322","海北","63","hai"];
　　aDQ[302]=["6323","黄南","63","huang"];
　　aDQ[303]=["6325","海南","63","qhhn"];
　　aDQ[304]=["6326","果洛","63","gl"];
　　aDQ[305]=["6327","玉树","63","ys"];
　　aDQ[306]=["6328","海西","63","hw"];
　　aDQ[307]=["6401","银川","64","yc"];
　　aDQ[308]=["6402","石嘴山","64","szs"];
　　aDQ[309]=["6403","吴忠","64","wz"];
　　aDQ[310]=["6405","中卫","64","zw"];
　　aDQ[311]=["6501","乌鲁木齐","65","wlmq"];
　　aDQ[312]=["6502","克拉玛依","65","klmy"];
　　aDQ[313]=["6523","昌吉","65","cj"];
　　aDQ[314]=["6527","博尔塔拉","65","betl"];
　　aDQ[315]=["6528","巴音郭楞","65","bygl"];
　　aDQ[316]=["6530","克孜勒苏柯尔克孜","65","kzlskekz"];
　　aDQ[317]=["6540","伊犁","65","xjyl"];
　　aDQ[318]=["7101","台北","71",""];
　　aDQ[319]=["7102","宜兰","71",""];
　　aDQ[320]=["7103","桃园","71",""];
　　aDQ[321]=["7104","新竹","71",""];
　　aDQ[322]=["7105","苗栗","71",""];
　　aDQ[323]=["7106","台中","71",""];
　　aDQ[324]=["7107","彰化","71",""];
　　aDQ[325]=["7108","南投","71",""];
　　aDQ[326]=["7109","云林","71",""];
　　aDQ[327]=["7110","嘉义","71",""];
　　aDQ[328]=["7111","台南","71",""];
　　aDQ[329]=["7112","高雄","71",""];
　　aDQ[330]=["7113","屏东","71",""];
　　aDQ[331]=["7114","台东","71",""];
　　aDQ[332]=["7115","花莲","71",""];
　　aDQ[333]=["7116","澎湖","71",""];
　　aDQ[334]=["7117","基隆","71",""];
　　aDQ[335]=["7118","金门","71",""];
　　aDQ[336]=["7119","马祖","71",""];
　　aDQ[337]=["8101","新界","81",""];
　　aDQ[338]=["8102","香港岛","81",""];
　　aDQ[339]=["8103","大屿山","81",""];
　　aDQ[340]=["8104","九龙","81",""];
　　aDQ[341]=["8201","澳门本岛","82",""];
　　aDQ[342]=["8202","凼仔","82",""];
　　aDQ[343]=["8203","路环","82",""];

　　//通过 DOM 创建下拉框 http://school.cnd8.com/qq.asp
　　//obj:下拉框的 options 数据集
　　//id:下拉框的 id
　　function CreateDropDownList(obj,id)
　　......{
　　    var sel=document.getElementById(id);
　　    sel.options.length=1;   //保存"—请选择—"
　　    //对于省份、城市常用 Array 存储，对于县、镇则用C#从数据库读取
　　    if(obj==null)return;
　　    if(obj instanceof Array)
　　    ......{
　　        for(var i=0;iobj.length;i++)
　　        ......{
　　            var op=document.createElement("option");
　　            op.setAttribute("value",obj[i][0]);
　　            var txt=document.createTextNode(obj[i][1]);
　　            op.appendChild(txt);
　　            sel.appendChild(op);
　　        }
　　    }
　　    else
　　    ......{
　　        for(var i=0;iobj.Rows.length;i++)  //注意这里是 length 不是 Count
　　        ......{
　　            var op=document.createElement("option");
　　            op.setAttribute("value",obj.Rows[i].ID);    //注意区分大小写
　　            var txt=document.createTextNode(obj.Rows[i].NAME);  //根 DataTable 的列名称要一致
　　            op.appendChild(txt);
　　            sel.appendChild(op);
　　        }
　　    }
　　    //绑定下一个下拉框
　　    switch(id)
　　    ......{
　　        case "SF":sel.onchange=function()......{ClearXianZhen();CreateDropDownList(GetArray(this.value),"CS");};break;
　　        case "CS":sel.onchange=function()......{ClearZhen();CreateDropDownList(Area.GetDataTable(this.value,AreaEnum.Xian).value,"Xian");};break;  //JS 向 C# 传递参数，并取得 C# 的返回值
　　        case "Xian":sel.onchange=function()......{CreateDropDownList(Area.GetDataTable(this.value,AreaEnum.Zhen).value,"Zhen");};break;   //返回值.value
　　        default:sel.onchange=function()......{alert(this.value);};break;
　　    }
　　}

　　//执行入口
　　var arr=GetArray("0");
　　CreateDropDownList(arr,"SF");

　　//获取要求的数组
　　//tar=所属的省份ID
　　function GetArray(val)
　　......{
　　    var temp=new Array();
　　    var j=0;
　　    for(var i=0;iaDQ.length;i++)
　　    ......{
　　        if(aDQ[i][2].toString()==val)
　　        ......{
　　            temp[j]=aDQ[i];
　　            //temp[j].push(aDQ[i]);
　　            j++;
　　        }
　　    }
　　    return temp;
　　}

　　//清空"镇"下拉框
　　function ClearZhen()
　　......{
　　    CreateDropDownList(null,"Zhen");
　　}
　　//清空"县"和"镇"下拉框
　　function ClearXianZhen()
　　......{
　　    CreateDropDownList(null,"Xian");
　　    CreateDropDownList(null,"Zhen");
　　}

　　/script

　　    /form
　　/body
　　/html

　　using System;
　　using System.Data;
　　using System.Data.OracleClient;

　　public partial class Area : System.Web.UI.Page
　　...{
　　    protected void Page_Load(object sender, EventArgs e)
　　    ...{
　　        //将C#的类和枚举分别注册到JS里
　　        AjaxPro.Utility.RegisterTypeForAjax(typeof(Area));
　　        AjaxPro.Utility.RegisterEnumForAjax(typeof(AreaEnum));
　　    }

　　    /**//// summary
　　    /// 取得下拉框所需数据
　　    /// /summary
　　    /// param name="UpID"上一级ID/param
　　    /// param name="ae"县/镇/param
　　    /// returns返回 DataTable/returns
　　    [AjaxPro.AjaxMethod]
　　    public DataTable GetDataTable(string UpID, AreaEnum ae)
　　    ...{
　　        if (String.IsNullOrEmpty(UpID))
　　            return null;

　　        string link = "server=XXX;user=XXX;pwd=XXX;";
　　        OracleConnection conn = new OracleConnection(link);

　　        //Oracle 返回的 DataTable 里的列名全是大写，在页面取值时记得大写
　　        string sql;
　　        if (Enum.Equals(ae, AreaEnum.Xian))
　　            sql = "SELECT id,name FROM City WHERE THREEID=0 AND TWOID=" + UpID;
　　        else
　　            sql = "SELECT id,name FROM City WHERE THREEID=" + UpID;

　　        OracleDataAdapter adapter = new OracleDataAdapter(sql, conn);
　　        DataTable table = new DataTable();
　　        adapter.Fill(table);
　　        return table;
　　    }
　　}

　　/**//// summary
　　/// 地区枚举
　　/// /summary
　　public enum AreaEnum
　　...{
　　    /**//// summary
　　    /// 县
　　    /// /summary
　　    Xian,
　　    /**//// summary
　　    /// 镇
　　    /// /summary
　　    Zhen
　　}

　　 到此基本功能实现，还有些功能（通过域名IP来判断地区并直接绑定，将选择好的地区保存，方便的读/存城市信息以便做成控件 等等）。有空再写完。

　　记得在 Web.config 的 system.web 加入

　　httpHandlers
　　    add verb="POST,GET" path="ajaxpro/*.ashx" type="AjaxPro.AjaxHandlerFactory, AjaxPro.2"/
　　/httpHandlers