自定义控件获取邮政编码（包含国家、省市联动）

    说明：由于项目需要，制作一个复杂的 TextBox 自定义控件，功能是控件内部可以通过国家、省市联动来获取邮政编码，显示在 Text 中，该控件的对外接口就是 Text 属性，其他程序可以通过 Text 属性来 设置或获取邮政编码。
源码下载：自定义控件获取邮政编码（包含国家、省市联动）
其中有一些问题，希望能和大家一起探讨。
    该控件分三大块：控件逻辑代码（GetZip.cs）、js 代码（ajaxData.js）和 异步数据获取代码（ZipCode.ashx），
详细如下：
1、GetZip.cs：

Code
  1using System;
  2using System.Collections.Generic;
  3using System.ComponentModel;
  4using System.Text;
  5using System.Web;
  6using System.Web.UI;
  7using System.Web.UI.WebControls;
  8using System.Drawing;
  9using System.Collections;
 10using System.Data;
 11using System.Data.SqlClient;
 12using System.Web.UI.HtmlControls;
 13using DBUtility;
 14namespace Zip
 15{
 16    [DefaultProperty("Text")]
 17    [ToolboxData("<{0}:GetZip runat=server></{0}:GetZip>")]
 18    public class GetZip : WebControl, ICallbackEventHandler, INamingContainer, ICompositeControlDesignerAccessor
 19    {
 20        //private int _PollingInterval = 5;
 21        private string str;
 22        private string targetObject;
 23        private string type;
 24        /**//// <exclude />
 25        protected override HtmlTextWriterTag TagKey
 26        {
 27            get
 28            {
 29                return HtmlTextWriterTag.Span;
 30            }
 31        }
 32        [Bindable(true)]
 33        [Category("Appearance")]
 34        [DefaultValue("")]
 35        [Localizable(true)]
 36        public string Text
 37        {
 38            get
 39            {
 40                //String s = (String)ViewState["Text"];
 41                //return ((s == null) ? String.Empty : s);
 42                return text.Text;
 43            }
 44
 45            set
 46            {
 47                //ViewState["Text"] = value;
 48                text.Text = value;
 49            }
 50        }
 51        public override bool EnableViewState
 52        {
 53            get { return base.EnableViewState; }
 54            set { base.EnableViewState = true; }
 55        }
 56        private Color _fontColor = Color.Black;//声明字体颜色变量
 57        private Color _backColor = Color.White;//声明控件背景变量
 58        private WebControl container = new WebControl(HtmlTextWriterTag.Span);
 59        private WebControl floatContainer = new WebControl(HtmlTextWriterTag.Span);
 60        private HtmlInputButton button = new HtmlInputButton();
 61        private HtmlInputButton getButton = new HtmlInputButton();
 62        private TextBox text = new TextBox();
 63        private TextBox codeText = new TextBox();
 64        private DropDownList countryDropDownList = new DropDownList();
 65        private DropDownList stateDropDownList = new DropDownList();
 66        private DropDownList cityDropDownList = new DropDownList();
 67        private Label countryLabel = new Label();
 68        private Label stateLabel = new Label();
 69        private Label cityLabel = new Label();
 70        private Label zipCodeLabel = new Label();
 71        protected internal WebControl Container
 72        {
 73            get
 74            {
 75                this.EnsureChildControls();
 76                return this.container;
 77            }
 78        }
 79        protected internal WebControl FloatContainer
 80        {
 81            get
 82            {
 83                this.EnsureChildControls();
 84                return this.floatContainer;
 85            }
 86        }
 87        protected internal HtmlInputButton Button
 88        {
 89            get
 90            {
 91                this.EnsureChildControls();
 92                return this.button;
 93            }
 94        }
 95        protected internal HtmlInputButton GetButton
 96        {
 97            get
 98            {
 99                this.EnsureChildControls();
100                return this.getButton;
101            }
102        }
103        protected internal TextBox OutText
104        {
105            get
106            {
107                this.EnsureChildControls();
108                return this.text;
109            }
110        }
111        protected internal TextBox CodeText
112        {
113            get
114            {
115                this.EnsureChildControls();
116                return this.codeText;
117            }
118        }
119        protected internal DropDownList CountryDropDownList
120        {
121            get
122            {
123                this.EnsureChildControls();
124                return this.countryDropDownList;
125            }
126        }
127        protected internal DropDownList StateDropDownList
128        {
129            get
130            {
131                this.EnsureChildControls();
132                return this.stateDropDownList;
133            }
134        }
135        protected internal DropDownList CityDropDownList
136        {
137            get
138            {
139                this.EnsureChildControls();
140                return this.cityDropDownList;
141            }
142        }
143        protected internal Label CountryLabel
144        {
145            get
146            {
147                this.EnsureChildControls();
148                return this.countryLabel;
149            }
150        }
151        protected internal Label StateLabel
152        {
153            get
154            {
155                this.EnsureChildControls();
156                return this.StateLabel;
157            }
158        }
159        protected internal Label CityLabel
160        {
161            get
162            {
163                this.EnsureChildControls();
164                return this.cityLabel;
165            }
166        }
167        protected internal Label ZipCodeLabel
168        {
169            get
170            {
171                this.EnsureChildControls();
172                return this.zipCodeLabel;
173            }
174        }
175        public GetZip()
176        {
177           
178        }
179        //根据自己的需要添加或重载符合控件的公共属性#region//根据自己的需要添加或重载符合控件的公共属性
180        //字体颜色属性
181        [Bindable(false), Category("Appearance"), DefaultValue("")]
182        public override Color ForeColor
183        {
184            get
185            {
186                return this._fontColor;
187            }
188            set
189            {
190                this._fontColor = value;
191            }
192        }
193
194        //控件背景属性
195        [Bindable(false), Category("Appearance"), DefaultValue("")]
196        public override Color BackColor
197        {
198            get
199            {
200                return this._backColor;
201            }
202            set
203            {
204                this._backColor = value;
205            }
206        }
207          //控件宽度属性
208
209        [Bindable(false),
210
211        Category("Appearance"),
212
213        DefaultValue("")]
214
215        public override Unit Width
216        {
217
218            get
219            {
220
221                return this.container.Width;
222
223            }
224
225            set
226            {
227
228                this.container.Width = value;
229
230            }
231
232        }
233
234          //控件高度属性
235
236        [Bindable(false),
237
238        Category("Appearance"),
239
240        DefaultValue("")]
241
242        public override Unit Height
243        {
244
245            get
246            {
247
248                return this.container.Height;
249
250            }
251
252            set
253            {
254
255                this.container.Height = value;
256
257            }
258
259        }
260
261          //控件边框颜色属性
262
263        [Bindable(false),
264
265        Category("Appearance"),
266
267        DefaultValue("")]
268
269        public override Color BorderColor
270        {
271
272            get
273            {
274
275                return this.container.BorderColor;
276
277            }
278
279            set
280            {
281
282                this.container.BorderColor = value;
283
284            }
285
286        }
287
288          //控件边框样式属性
289
290        [Bindable(false),
291
292        Category("Appearance"),
293
294        DefaultValue("")]
295
296        public override BorderStyle BorderStyle
297        {
298
299            get
300            {
301
302                return this.container.BorderStyle;
303
304            }
305
306            set
307            {
308
309                this.container.BorderStyle = value;
310
311            }
312
313        }
314
315          //控件边框宽度属性
316
317        [Bindable(false),
318
319        Category("Appearance"),
320
321        DefaultValue("")]
322
323        public override Unit BorderWidth
324        {
325
326            get
327            {
328
329                return this.container.BorderWidth;
330
331            }
332            set
333            {
334
335                this.container.BorderWidth = value;
336
337            }
338        }
339        #endregion
340        /**//// <exclude/>
341        protected override void Render(HtmlTextWriter writer)
342        {
343            
344            this.EnsureChildControls();
345            RenderBeginTag(writer);
346            RenderChildren(writer);
347            RenderEndTag(writer);
348        }       
349        protected override void OnPreRender(EventArgs e)
350        {
351            base.OnPreRender(e);
352            RegisterScript();
353        }
354
355        private void RegisterScript()
356        {
357            /**///// Add style sheet to parent page
358
359            //string cssUrl = Page.ClientScript.GetWebResourceUrl(this.GetType(), "WhoIsLooking.Stylesheet.css");
360
361            //HtmlLink cssLink = new HtmlLink();
362
363            //cssLink.Href = cssUrl;
364
365            //cssLink.Attributes.Add("rel", "stylesheet");
366
367            //cssLink.Attributes.Add("type", "text/css");
368
369            //this.Page.Header.Controls.Add(cssLink);
370
371            /**///// Add class name
372
373            //this.CssClass = "Stylesheet";
374            // Force Session State to create Session Id
375            //Context.Session["WhoIsLooking"] = "1";
376            //Page.ClientScript.GetWebResourceUrl(this.GetType(), "Zip.js");
377             //Add Javascript include
378            string scriptUrl2 = Page.ClientScript.GetWebResourceUrl(this.GetType(), "Zip.ajaxData.js");
379            Page.ClientScript.RegisterClientScriptInclude("ajaxData", scriptUrl2);
380            //string[] parastr = new string[2]{"str","targerObject"};
381            //String cbReference = Page.ClientScript.GetCallbackEventReference(this, "arr", "ShowValues", null, true);
382            //String callbackScript;
383            /**/////string[] serverpara = new string[3] { "id", "targetObj","type" };
384            //callbackScript = "function CallServer(arr,context)" +
385            //    "{ " + cbReference + ";}";
386            //Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "CallServer", callbackScript, true);
387            String scriptKey = "zip.Panel";
388            String arrayDeclaration = @"{ " +
389                " ID:'" + this.ClientID + "'" +
390                ", ContainerID:'" + this.Container.ClientID + "'" +
391                ", FloatContainerID:'" + this.FloatContainer.ClientID + "'" +
392                ", TextID:'" + this.OutText.ClientID + "'" +
393                ", CodeTextID:'" + this.CodeText.ClientID + "'" +
394                ", ButtonID:'" + this.Button.ClientID + "'" +
395                ", GetButtonID:'" + this.GetButton.ClientID + "'" +
396                ", CountryID:'" + this.CountryDropDownList.ClientID + "'" +
397                ", StateID:'" + this.StateDropDownList.ClientID + "'" +
398                ", CityID:'" + this.CityDropDownList.ClientID + "'" +
399                //", ListSize:" + this.Rows +
400            " }";
401            Page.ClientScript.RegisterStartupScript(typeof(Panel), scriptKey, "Zip_FloatPanel_Init();", true);
402            Page.ClientScript.RegisterArrayDeclaration("Zip_Controls", arrayDeclaration);
403
404        }
405        private void GetCountryList()
406        {
407            DataSet ds = SqlHelper.Query(SqlHelper.LocalSqlServer, "select * from Country_State_City_View where GroupName='Country'");
408            
409            //ds.ReadXml("Country.xml");
410            if (ds != null)
411            {
412                if (ds.Tables[0].Rows.Count > 0)
413                {
414                    for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
415                    {
416                        ListItem listItem = new ListItem();
417                        listItem.Text = ds.Tables[0].Rows[i]["CaptionMessageSignName"].ToString();
418                        listItem.Value = ds.Tables[0].Rows[i]["CaptionMessageID"].ToString();
419                        countryDropDownList.Items.Add(listItem);
420                    }
421                }
422            }
423        }
424        private void GeValueList(string eventArgument)
425        {
426            string[] stringarr = eventArgument.Split(',');
427            string id = stringarr[0];
428            targetObject = stringarr[1];
429            type = stringarr[2];
430            string groupName = "";
431            if (type == "1")
432            {
433                groupName = "State";
434            }
435            else if (type == "2")
436            {
437                groupName = "City";
438            }
439            DataSet ds = new DataSet();
440            StringBuilder sb = new StringBuilder();
441            if (type == "3")//get zip code by city
442            {
443                ds = SqlHelper.Query(SqlHelper.LocalSqlServer, "select * from Country_State_City_View where CaptionMessageID='" + id + "'");
444                //ds.ReadXml("City.xml");
445                if (ds != null)
446                {
447                    if (ds.Tables[0].Rows.Count > 0)
448                    {
449                        //DataView dv = ds.Tables[0].DefaultView;
450                        //dv.RowFilter = "CityID = " + id;
451                        sb.Append(",");
452                        sb.Append(ds.Tables[0].Rows[0]["CaptionMessage_JokerField_3"].ToString());
453                    }
454                }
455            }
456            else
457            {
458                ds = SqlHelper.Query(SqlHelper.LocalSqlServer, "select * from Country_State_City_View where GroupName='" + groupName + "' and GroupFatherID='" + id + "'");
459                //ds.ReadXml("State.xml");
460                if (ds != null)
461                {
462                    if (ds.Tables[0].Rows.Count > 0)
463                    {
464                        //DataView dv = ds.Tables[0].DefaultView;
465                        //dv.RowFilter = "CountryID = " + id;
466                        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
467                        {
468                            sb.Append(",");
469                            sb.Append(ds.Tables[0].Rows[i]["CaptionMessageID"].ToString());
470                            sb.Append("|");
471                            sb.Append(ds.Tables[0].Rows[i]["CaptionMessageSignName"].ToString());
472                        }
473                    }
474                }
475            }
476            str = sb.ToString().Substring(1);
477        }
478        /**//// <summary>
479        /// 保存自页回发到服务器后发生的任何服务器控件视图状态更改。
480        /// </summary>
481        /// <returns>返回服务器控件的当前视图状态。</returns>
482        protected override object SaveViewState()
483        {
484            object[] vState = new object[] { base.SaveViewState() };
485            return vState;
486        }
487
488        /**//// <summary>
489        ///从 SaveViewState 方法保存的上一个页请求还原视图状态信息。
490        /// </summary>
491        /// <param name="savedState">表示要还原的控件状态的 Object</param>
492        protected override void LoadViewState(object savedState)
493        {
494            if (savedState != null)
495            {
496                object[] vState = (object[])savedState;
497                if (vState[0] != null)
498                    base.LoadViewState(vState[0]);
499            }
500        }
501        protected override void CreateChildControls()
502        {
503            this.Controls.Clear();
504
505            base.CreateChildControls();
506
507            container.ID = "Container";
508            container.Style[HtmlTextWriterStyle.Position] = "relative";
509            this.Controls.Add(container);
510
511            text.ID = "Text";
512            container.Controls.Add(text);
513
514            button.ID = "Button";
515            button.Value = "get zip code";
516            button.Attributes.Add("onclick", "Zip_Button_Toggle(this);");
517            container.Controls.Add(button);
518
519            floatContainer.ID = "FloatContainer";
520            floatContainer.Style[HtmlTextWriterStyle.Position] = "relative";
521            floatContainer.Width = 80;
522            floatContainer.BorderWidth = 1;
523            floatContainer.BackColor = Color.Azure;
524            this.container.Controls.Add(floatContainer);
525
526            countryLabel.ID = "CountryLabel";
527            countryLabel.Text = "Country:";
528            //floatContainer.Controls.Add(countryLabel);
529
530            countryDropDownList.EnableViewState = true;
531            countryDropDownList.ID = "CountryDropDownList";
532            countryDropDownList.EnableViewState = true;
533            //floatContainer.Controls.Add(countryDropDownList);
534
535            //floatContainer.Controls.Add(HtmlTextWriterTag.Br);
536
537            stateLabel.ID = "StateLabel";
538            stateLabel.Text = "State:";
539            //floatContainer.Controls.Add(stateLabel);
540
541            stateDropDownList.EnableViewState = true;
542            stateDropDownList.ID = "StateDropDownList";
543            stateDropDownList.EnableViewState = true;
544            //floatContainer.Controls.Add(stateDropDownList);
545            
546            //floatContainer.Controls.Add(HtmlTextWriterTag.Br);
547
548            cityLabel.ID = "CityLabel";
549            cityLabel.Text = "City:";
550            floatContainer.Controls.Add(cityLabel);
551
552            cityDropDownList.EnableViewState = true;
553            cityDropDownList.EnableViewState = true;
554            cityDropDownList.ID = "CityDropDownList";
555            //floatContainer.Controls.Add(cityDropDownList);
556
557            //floatContainer.Controls.Add(HtmlTextWriterTag.Br);
558
559            zipCodeLabel.ID = "ZipCodeLabel";
560            zipCodeLabel.Text = "Zip Code:";
561            //floatContainer.Controls.Add(zipCodeLabel);
562
563            codeText.ID = "CodeText";
564            codeText.ReadOnly = true;
565            //codeText.Attributes["autocomplete"] = "off";
566            //floatContainer.Controls.Add(codeText);
567            //text.TextChanged += new EventHandler(this.raiseTextChanged);
568
569            //floatContainer.Controls.Add(HtmlTextWriterTag.Br);
570
571            getButton.ID = "GetButton";
572            getButton.Value = "select code";
573            getButton.Attributes.Add("onclick", "getZipCode(" + text.ClientID + "," + codeText.ClientID + ");");
574
575            HtmlTable showTable = new HtmlTable();
576            showTable.Rows.Add(new HtmlTableRow());
577            showTable.Rows.Add(new HtmlTableRow());
578            showTable.Rows.Add(new HtmlTableRow());
579            showTable.Rows.Add(new HtmlTableRow());
580            showTable.Rows.Add(new HtmlTableRow());
581
582            showTable.Rows[0].Cells.Add(new HtmlTableCell());
583            showTable.Rows[0].Cells.Add(new HtmlTableCell());
584            showTable.Rows[1].Cells.Add(new HtmlTableCell());
585            showTable.Rows[1].Cells.Add(new HtmlTableCell());
586            showTable.Rows[2].Cells.Add(new HtmlTableCell());
587            showTable.Rows[2].Cells.Add(new HtmlTableCell());
588            showTable.Rows[3].Cells.Add(new HtmlTableCell());
589            showTable.Rows[3].Cells.Add(new HtmlTableCell());
590            showTable.Rows[4].Cells.Add(new HtmlTableCell());
591
592            showTable.Rows[0].Cells[0].Controls.Add(countryLabel);
593            showTable.Rows[0].Cells[1].Controls.Add(countryDropDownList);
594            showTable.Rows[1].Cells[0].Controls.Add(stateLabel);
595            showTable.Rows[1].Cells[1].Controls.Add(stateDropDownList);
596            showTable.Rows[2].Cells[0].Controls.Add(cityLabel);
597            showTable.Rows[2].Cells[1].Controls.Add(cityDropDownList);
598            showTable.Rows[3].Cells[0].Controls.Add(zipCodeLabel);
599            showTable.Rows[3].Cells[1].Controls.Add(codeText);
600            showTable.Rows[4].Cells[0].Controls.Add(getButton);
601            floatContainer.Controls.Add(showTable);
602
603            countryDropDownList.Items.Add(new ListItem("Select Country", "0"));
604            countryDropDownList.Attributes.Add("onchange", "return GetValues(" + this.countryDropDownList.ClientID + "," + this.stateDropDownList.ClientID + ",\"1\")");
605            stateDropDownList.Attributes.Add("onchange", "return GetValues(" + this.stateDropDownList.ClientID + "," + this.cityDropDownList.ClientID + ",\"2\")");
606            cityDropDownList.Attributes.Add("onchange", "return GetValues(" + this.cityDropDownList.ClientID + "," + this.codeText.ClientID + ",\"3\")");
607            getButton.Attributes.Add("onclick", "getZipCode(" + text.ClientID + "," + codeText.ClientID + ");");
608            this.GetCountryList();
609        }
610        /**//// <exclude />
611        public override void DataBind()
612        {
613            this.OnDataBinding(EventArgs.Empty);
614            this.EnsureChildControls();
615            this.DataBindChildren();
616        }
617        private HtmlTextWriter getCorrectTagWriter(HtmlTextWriter writer)
618        {
619
620            HtmlTextWriter tagWriter = writer;
621
622            if (writer is System.Web.UI.Html32TextWriter)
623            {
624                HttpBrowserCapabilities browser = this.Page.Request.Browser;
625                if (browser.W3CDomVersion.Major > 0)
626                {
627                    tagWriter = new HtmlTextWriter(writer.InnerWriter);
628                }
629                else if (String.Compare(browser.Browser, "netscape", StringComparison.OrdinalIgnoreCase) == 0)
630                {
631                    if (browser.MajorVersion >= 5)
632                    {
633                        tagWriter = new HtmlTextWriter(writer.InnerWriter);
634                    }
635                }
636            }
637
638            return tagWriter;
639        }
640        /**//// <exclude/>
641        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2109:ReviewVisibleEventHandlers", MessageId = "0#")]
642        protected override void OnLoad(System.EventArgs e)
643        {
644            //this.isLoaded = true;
645            base.OnLoad(e);
646        }
647        /**//// <exclude/>
648        protected override void AddAttributesToRender(HtmlTextWriter writer)
649        {
650
651            if (this.Page != null)
652            {
653                this.Page.VerifyRenderingInServerForm(this);
654            }
655
656            base.AddAttributesToRender(writer);
657        }
658        /**//// <exclude />
659        protected virtual void RecreateChildControls()
660        {
661            base.ChildControlsCreated = false;
662            this.EnsureChildControls();
663        }
664
665        /**////// <exclude />
666        //void ICompositeControlDesignerAccessor.RecreateChildControls()
667        //{
668        //    this.RecreateChildControls();
669        //}
670        /**//// <exclude />
671        public override ControlCollection Controls
672        {
673            get
674            {
675                this.EnsureChildControls();
676                return base.Controls;
677            }
678        }
679
680        ICompositeControlDesignerAccessor 成员#region ICompositeControlDesignerAccessor 成员
681
682        /**//// <exclude />
683        void ICompositeControlDesignerAccessor.RecreateChildControls()
684        {
685            this.RecreateChildControls();
686        }
687
688        #endregion
689
690        ICallbackEventHandler 成员#region ICallbackEventHandler 成员
691
692        string ICallbackEventHandler.GetCallbackResult()
693        {
694            string[] ss = new string[3] { str, targetObject, type };
695            
696            return string.Join(",", ss);
697        }
698
699        void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
700        {
701            GeValueList(eventArgument);
702        }
703
704        #endregion
705    }
706}
707

2、ajaxData.js

    var xmlDom;
    function createXMLHTTP()
    {
        if(window.XMLHttpRequest)
        {
            xmlDom=new XMLHttpRequest();//mozilla浏览器
        }
        else if(window.ActiveXObject)
        {
            try
            {
                xmlDom=new ActiveXObject("Msxml2.XMLHTTP");//IE老版本
            }
            catch(e)
            {}
            try
            {
                xmlDom=new ActiveXObject("Microsoft.XMLHTTP");//IE新版本
            }
            catch(e)
            {}
            if(!xmlDom)
            {
                window.alert("不能创建XMLHttpRequest对象实例！");
                return false;
            }
        }
    }
function GetValues(obj,targetObj,type)
{
    if(obj.value!="")
    {
        createXMLHTTP();
        var strURL="UserFunction/HTTPProcess/ZipCode.ashx?id="+obj.value+"&type="+type;
        xmlDom.open("GET",strURL,true);
        xmlDom.onreadystatechange = function(){ShowValues(targetObj,type);};
        xmlDom.send(null);
    }
}
function ShowValues(targetObj,type)
{
if (xmlDom.readyState == 4 && xmlDom.status == 200)
        {
        var arr = xmlDom.responseText;
    if(arr != ""|| arr!=null)
    {

        
//        if(arr.indexOf("=")>0)
//        {
//            arr = arr.substr(arr.indexOf("=")+1);
//        }
        var array = arr.split(",");
        var result = array;
//        var targetObj = document.getElementById(array[array.length-2]);
//        var type = array[array.length-1];
        
        if(targetObj!=null)
        {
            
            if(type=="3")
            {
                targetObj.value = result[0];
            }
            else
            {
                delValues(targetObj);//delete
        //                var piArray = result.split(",");
                if(type=="1")
                {
                    targetObj.options.add(new Option("Select a State/Province","0"));
                }
                else if(type=="2")
                {
                    targetObj.options.add(new Option("Select a Metro or City","0"));
                }
                for(var i=0;i<result.length;i++)
                {
                   var ary1 = result[i].toString().split("|");
                   targetObj.options.add(new Option(ary1[1].toString(),ary1[0].toString()));
                }
            }
        }
    }
    else
    {
     alert("sorry It has no data in database");
    }
    }
}
//delete values
function delValues(targetObject)
{
                        
    targetObject.innerHTML="";
}
function getZipCode(targerControl,originControl)
{
    targerControl.value = originControl.value;
    Panle_Hide(targerControl.Container.FloatContainer);
}

function selectZip()
{
//    if(document.all["details"].style.visibility=="hidden")
//    {
//        document.all["details"].style.visibility="visible";
//    }
//    else
//    {
//        document.all["details"].style.visibility=="hidden";
//    }
    hiddenPanel();
}
function hiddenPanel()
{
    document.getElementById("showPanel").style.display = "none";
}
function Zip_FloatPanel_Init()
{
    for( var i = 0; i < Zip_Controls.length; i++ ) {
        var info = Zip_Controls[ i ];
        Zip_FloatPanel_Load( info );
    }


}
function Zip_FloatPanel_Load( info )
{   
    var ZipCode = document.getElementById( info.ID );
    var Container = document.getElementById( info.ContainerID );
    var FloatContainer = document.getElementById( info.FloatContainerID );
    var Text = document.getElementById( info.TextID );
    var CodeText = document.getElementById( info.CodeTextID );
    var Button = document.getElementById( info.ButtonID );
    var GetButton = document.getElementById( info.GetButtonID );
    var Country = document.getElementById( info.CountryID );
    var State = document.getElementById( info.StateID );
    var City = document.getElementById( info.CityID );
    
    ZipCode.style.display = "";
    
    Container.FloatContainer = FloatContainer;
    Container.Text = Text;
    Container.Button = Button;
    FloatContainer.Container = Container;
    Text.Container = Container;
    Button.Container = Container;
    
    FloatContainer.CodeText = CodeText;
    FloatContainer.GetButton = GetButton;
    FloatContainer.Country = Country;
    FloatContainer.State = State;
    FloatContainer.City = City;
    CodeText.FloatContainer = FloatContainer;
    GetButton.FloatContainer = FloatContainer;
    Country.FloatContainer = FloatContainer;
    State.FloatContainer = FloatContainer;
    City.FloatContainer = FloatContainer;
    
    FloatContainer.style.display = "none";
    FloatContainer.style.position = "absolute";
    FloatContainer.style.left = "0px";
    
    FloatContainer.style.zIndex = 10000;
//    showPanel.size = ( info.ListSize > List.options.length ) ? List.options.length : info.ListSize;
    FloatContainer.multiple = false;
    FloatContainer.IsShowing = false;
//    FloatContainer.Show = Panle_Show;
//    FloatContainer.Hide = Panle_Hide;    
}
function Zip_Button_Toggle(button) {
    if ( button.Container.FloatContainer.IsShowing == true ) {
//        this.FloatContainer.Hide();
        Panle_Hide(button.Container.FloatContainer)
    } else {
        Panle_Show(button.Container.FloatContainer);
    }
}
function Panle_Show(floatContainer) {
    if ( !floatContainer.IsShowing && !floatContainer.disabled ) {
//        if ( typeof ( this.Container.Text.dataSrc ) != "undefined" ) { // to overcome misaligniment in IE
//            this.style.top = ( this.Container.offsetHeight + 10 ) + "px";
//        } else {
            floatContainer.style.top = ( floatContainer.Container.offsetHeight ) + "px";
//        }
//        this.style.width = this.Container.offsetWidth + "px";
        
//        this.style.width = "100px";
        floatContainer.style.display = "";
        floatContainer.focus();
        floatContainer.IsShowing = true;
    }
}
function Panle_Hide(floatContainer) {
    if ( floatContainer.IsShowing ) {
        floatContainer.style.display = "none";
        floatContainer.IsShowing = false;
    }
}

3、ZipCode.ashx（这里的逻辑可以根据自己的数据库结构来定）,该页面是独立出来的，放在被引用的项目中，没有和自定义控件一起编译进去，这里是一个问题，有没有朋友解决一下把这个文件一起编译到 zip 的自定义控件中，这样一来就更方便了。

Code
 1<%@ WebHandler Language="C#" Class="ZipCode" %>
 2
 3using System;
 4using System.Web;
 5using System.Text;
 6using System.Data;
 7using DBUtility;
 8public class ZipCode : IHttpHandler
 9{
10
11    public void ProcessRequest(HttpContext context)
12    {
13        context.Response.ContentType = "text/plain";
14        string id = context.Request["id"];//country id or state id or city id
15        string type = context.Request["type"];//0 means country;1 means state;2 means city
16        DataSet ds = new DataSet();
17        StringBuilder sb = new StringBuilder();
18        string str = "";
19        if (id != "" && type != "")
20        {
21            string groupName = "";
22            if (type == "1")
23            {
24                groupName = "State";
25            }
26            else if (type == "2")
27            {
28                groupName = "City";
29            }
30            if (type == "3")//get zip code by city
31            {
32                ds = SqlHelper.Query(SqlHelper.LocalSqlServer, "select * from Country_State_City_View where CaptionMessageID='" + id + "'");
33                //ds.ReadXml("City.xml");
34                if (ds != null)
35                {
36                    if (ds.Tables[0].Rows.Count > 0)
37                    {
38                        //DataView dv = ds.Tables[0].DefaultView;
39                        //dv.RowFilter = "CityID = " + id;
40                        sb.Append(",");
41                        sb.Append(ds.Tables[0].Rows[0]["CaptionMessage_JokerField_3"].ToString());
42                    }
43                }
44            }
45            else
46            {
47                ds = SqlHelper.Query(SqlHelper.LocalSqlServer, "select * from Country_State_City_View where GroupName='" + groupName + "' and GroupFatherID='" + id + "'");
48                //ds.ReadXml("State.xml");
49                if (ds != null)
50                {
51                    if (ds.Tables[0].Rows.Count > 0)
52                    {
53                        //DataView dv = ds.Tables[0].DefaultView;
54                        //dv.RowFilter = "CountryID = " + id;
55                        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
56                        {
57                            sb.Append(",");
58                            sb.Append(ds.Tables[0].Rows[i]["CaptionMessageID"].ToString());
59                            sb.Append("|");
60                            sb.Append(ds.Tables[0].Rows[i]["CaptionMessageSignName"].ToString());
61                        }
62                    }
63                }
64            }
65        }
66        str = (sb!=null?sb.ToString().Substring(1):"");
67        if (str != "")
68        {
69            context.Response.Write(str);
70        }
71    }
72
73    public bool IsReusable
74    {
75        get
76        {
77            return false;
78        }
79    }
80}
81

      有一个问题需要大家帮忙，就是在国家、省市联动那一块，我用的是 ajax 来实现的，而没有用微软自带的 ICallbackEventHandler 功能来实现，原因是用 ICallbackEventHandler 来实现出现一个问题。就是在引用的页面代码里加 Response.Write() 功能时，该控件的联动不可用，代码就不贴出来了，以下有源码下载，请朋友帮忙.
源码：自定义控件（问题）