最近做的一个类似Google自动完成的服务器控件

项目背景：

      最近项目中需要根据公司选择该公司的部门，根据公司查找该公司的员工。其实类似于以前做过的级联菜单，

选择一级城市后过滤二级城市。为了方便输入，做成了一个控件。

实现：

      因为该控件服务器端主要是继承至CompositeControl控件，里面注册了一个TextBox,HiddenField,和

Image三个服务器端控件，然后注册js调用该控件客户端的初始化函数。没有特别的东西，故不贴出来了。

客户端js还是比较多的，有些比较重要的东西。先看代码

if(typeof("sg_AutoFilterState")!='object')
    sg_AutoFilterState = [];
if(typeof("sg_AutoFilterIndex")!='object')
    sg_AutoFilterIndex = [];

function sg_AutoFilter(id,targetcontrolid,popupcontrolid,hiddenControlId,initvalue,selecttype)
{
    sg_AutoFilterState[id]=this;
    sg_AutoFilterIndex[sg_AutoFilterIndex.length]=this;
    
    this.TargetControl=$get(targetcontrolid);
    this.PopupControl=$get(popupcontrolid);
    this.HiddenControl=$get(hiddenControlId);
    this.DropdownPanelSelectedItem=[];//eg:[{text:张三,value:800382}]
    this.TargetPanelSelectedItem=[];//eg:[{fieldname:branchid,fieldvalue:469}]
    this.DropdownPanel=null;
    this.PopupPanel=null;
    this.TextChanged=null;
    this.DisplayRrecordsCount=10;
    this.MultiSelect=false;
    this.FilterInitValue=initvalue;
    this.SelectType=selecttype;
    this._bgcolr=null;
    this._currentSelect=-1;
    this._oldSelectItem=null;
}

sg_AutoFilter.prototype = {
    initialize:function(){
        this.TargetControl.onfocus=Function.createDelegate(this,this.add_TextChanged);
        this.TargetControl.onblur=Function.createDelegate(this,this._textBlur);
        this.add_PopupClick();
    },
    
    get_DropdownPanelSelectedItem:function(){
        return this.DropdownPanelSelectedItem;
    },
    
    set_DropdownPanelSelectedItem:function(item){
        this.DropdownPanelSelectedItem[this.DropdownPanelSelectedItem.length]=item;
    },
    
    get_TargetPanelSelectedItem:function(){
        return this.TargetPanelSelectedItem;
    },
    
    set_TargetPanelSelectedItem:function(item){
        this.TargetPanelSelectedItem[this.TargetPanelSelectedItem.length]=item;
    },
    
    add_TextChanged:function(){
        var targetDiv=document.createElement('DIV');
        var region=Sys.UI.DomElement.getBounds(this.TargetControl);
        targetDiv.style.left=region.x;
        targetDiv.style.width= (region.width <= 0)?150:region.width;
        targetDiv.style.top=region.y+region.height;
        targetDiv.style.height=this.DisplayRrecordsCount*25;
        targetDiv.style.display='none';
        targetDiv.style.zIndex=1000;
        targetDiv.style.position="absolute";
        targetDiv.style.backgroundColor="#C9DAE9";
        targetDiv.style.border="1px solid #000000";
        this.TargetControl.parentElement.appendChild(targetDiv);
        this.DropdownPanel=targetDiv;
        this.TargetControl.onpropertychange=Function.createDelegate(this,this._textChanged);
        
    },
    
    remove_TextChanged:function(handler){
        $removeHandler(this.TargetControl,'propertychange',handler);
    },
    
    add_PopupClick:function(){
        var popupDiv=document.createElement('DIV');
        var region=Sys.UI.DomElement.getBounds(this.PopupControl);
        popupDiv.style.left=region.x;
        popupDiv.style.width=160;
        popupDiv.style.height=120;
        popupDiv.style.overflow="auto";
        popupDiv.style.top=region.y+region.height;
        popupDiv.style.display='none';
        popupDiv.style.zIndex=1000;
        popupDiv.style.position="absolute";
        popupDiv.style.backgroundColor="#C9DAE9";
        popupDiv.style.border="1px solid #000000";
        popupDiv.style.scrollbar3dLightColor="#A6CAEE";
        popupDiv.style.scrollbarBaseColor="#c9dae9";
        popupDiv.style.scrollbarArrowColor="#000000";
        popupDiv.style.scrollbarShadowColor="#c9dae9";
        popupDiv.style.scrollbarFaceColor="#c9dae9";
        popupDiv.style.scrollbarTrackColor="#c9dae9";
        this.PopupControl.parentElement.appendChild(popupDiv);
        this.PopupPanel=popupDiv;
        this.PopupControl.onclick=Function.createDelegate(this,this._popupClickHandler);
    },
    
    remove_PopupClick:function(handler){
        $removeHandler(this.PopupControl,'click',handler);
    },
   
    set_DisplayRrecordsCount:function(value){
        if(value)
            this.DisplayRrecordsCount=value;
    },
    
    set_DisplayRrecordsCount:function(){
        return this.DisplayRrecordsCount;
    },
    
    show_DropdownPanel:function(){
        if(self.frameElement)
        {
            var p = this._getPosition(this.TargetControl);
            this.DropdownPanel.style.left = p.x;
            this.DropdownPanel.style.top = p.y;
        }
        this.DropdownPanel.style.display='';

    },

    hide_DropdownPanel:function(){
        if(this.DropdownPanel)
            this.DropdownPanel.style.display='none';
    },
    
    get_Text:function(){
        return this.TargetControl.value;
    },
    
    set_Text:function(text){
        this.TargetControl.value=text;
    },
    
    get_Value:function(){
        return this.HiddenControl.value;
    },
    
    set_Value:function(value){ 
        this.HiddenControl.value=value;
    },
    
    _textChanged:function(){
        //if(this.TargetControl.value.trim()=='') return;
        this.show_DropdownPanel();
        var xmldom=sg.xmlDocument();
        var root=xmldom.createElement("Root");
        if(this.SelectType=="SelectOrganization")
            root.setAttribute("type","SelectOrganization");
        if(this.SelectType=="SelectPosition")
            root.setAttribute("type","SelectPosition");
        if(this.SelectType=="SelectPerson")
            root.setAttribute("type","SelectPerson");    
        xmldom.appendChild(root);
        var keyword=xmldom.createElement("keyword");
        keyword.text=this.TargetControl.value;
        root.appendChild(keyword);
        var branchid=xmldom.createElement("branchid");
        if(this.TargetPanelSelectedItem.length==0)
            branchid.text=this.FilterInitValue;
        else
            branchid.text=this.TargetPanelSelectedItem[this.TargetPanelSelectedItem.length-1].Value;
        root.appendChild(branchid);
        var maxrecord=xmldom.createElement("maxrecord");
        maxrecord.text=this.DisplayRrecordsCount;
        root.appendChild(maxrecord);
        
        if(sg.Location)
            var result = sg.SendXmlDataSync(sg.Location+"ajax/share/sgAutoFilter.ashx",xmldom).responseText;
        else
            var result = sg.SendXmlDataSync("ajax/share/sgAutoFilter.ashx",xmldom).responseText;
        this.DropdownPanel.innerHTML=result;
        this._currentSelect=-1;
        //为下拉面板添加事件
        var liList = this.DropdownPanel.getElementsByTagName("LI");
        for(var i=0;i<liList.length;i++)
        {
            var li=liList[i];
            li.onmousedown = Function.createDelegate(this,this._onClickRowHandler);
            li.onmouseover = Function.createDelegate(this,this._onMouseOverRowHandler);
            li.onmouseout = Function.createDelegate(this,this._onMouseOutRowHandler);
       }
        document.onkeydown=Function.createDelegate(this,this._keydown);
    },    
    
    _textBlur:function(){
        this.DropdownPanel.style.display='none';
    },
    
    _keydown:function(){
        if(this.DropdownPanel.style.display=='')
        {
            var liList = this.DropdownPanel.getElementsByTagName("LI");
            if(event.keyCode==40)//向下
            {
                if(this._currentSelect==liList.length-1)
                {
                    var li=liList[this._currentSelect];
                    li.style.backgroundColor="#FFCCCC";
                    if(this._oldSelectItem)
                        this._oldSelectItem.style.backgroundColor=this._bgcolr;
                    this._oldSelectItem=li;
                    return;
                }
                this._currentSelect++;
                var li=liList[this._currentSelect];
                this._bgcolr=li.style.backgroundColor;
                li.style.backgroundColor="#FFCCCC";
                if(this._oldSelectItem)
                    this._oldSelectItem.style.backgroundColor=this._bgcolr;
                this._oldSelectItem=li;
            }
            if(event.keyCode==38)//向上
            {
                if(this._currentSelect==-1)
                    return;
                if(this._currentSelect==0)
                {
                    var li=liList[this._currentSelect];
                    li.style.backgroundColor="#FFCCCC";
                    if(this._oldSelectItem)
                    this._oldSelectItem.style.backgroundColor=this._bgcolr;
                    this._oldSelectItem=li;
                    return;
                }
                this._currentSelect--;
                var li=liList[this._currentSelect];
                li.style.backgroundColor="#FFCCCC";
                if(this._oldSelectItem)
                    this._oldSelectItem.style.backgroundColor=this._bgcolr;
                this._oldSelectItem=li;
            }
            if(event.keyCode==13)
            {
                if(this._currentSelect==-1)
                    return;
                var li=liList[this._currentSelect];
                this.TargetControl.value=li.innerText;
                this.HiddenControl.value=li.id.split('_')[1];
                this.DropdownPanel.style.display='none';
                this.set_Text(this.TargetControl.value);
                this.set_Value(li.id.split('_')[1]);
                var item = {"text":this.TargetControl.value,"value":li.id.split('_')[1]}
                this.DropdownPanelSelectedItem.push(item);
            }
            if(event.keyCode==27)
            {
                this.DropdownPanel.style.display='none';
            }
        }
    },
    
    _popupClickHandler:function(){
    //debugger
        if(this.PopupPanel.style.display=='none')
        {
            if(self.frameElement)
            {
                var p = this._getPosition(this.TargetControl);
                this.PopupPanel.style.left = p.x;
                this.PopupPanel.style.top = p.y;
            }
            this.PopupPanel.style.display='';
        }
        else
        {
            this.PopupPanel.style.display='none'; 
            var chekboxList = this.PopupPanel.getElementsByTagName('INPUT'); 
            for(var i=0;i<chekboxList.length;i++)
            {
                if(chekboxList[i].checked==true)
                {
                    var fieldName=chekboxList[i].id.split('_')[1];
                    var fieldValue=chekboxList[i].id.split('_')[2];
                    var item={"Name":fieldName,"Value":fieldValue};
                    this.TargetPanelSelectedItem.push(item);
                }
            }
            
        }
    },
    
    
    _onClickRowHandler:function(){
        this.TargetControl.value=event.srcElement.innerText;
        this.HiddenControl.value=event.srcElement.id.split('_')[1];
        this.set_Text(this.TargetControl.value);
        this.set_Value(event.srcElement.id.split('_')[1]);
    },
    
    _onMouseOverRowHandler:function(){
        var liList = this.DropdownPanel.getElementsByTagName("LI");
        this._bgcolr=event.srcElement.style.backgroundColor;
        event.srcElement.style.backgroundColor="#FFCCCC";
        if(this._currentSelect<liList.length)
            this._currentSelect++;
    },
    
    _onMouseOutRowHandler:function(){
        event.srcElement.style.backgroundColor=this._bgcolr;
        if(this._currentSelect>0)
            this._currentSelect--;
    },
    
    _getPosition:function(control){
        var elementParent = control;
        var scrollHeight = 0;
        var topHeight=0;
        var leftWidth = 0;
        while(elementParent.tagName!="BODY")
        {
            if(elementParent.style.position=="absolute")
            {
                elementParent = elementParent.offsetParent;
                continue;
            }
            topHeight+=elementParent.offsetTop;
            if(elementParent.tagName=="DIV")
            {
                topHeight = topHeight - elementParent.scrollTop;
                leftWidth = leftWidth - elementParent.scrollLeft;
                scrollHeight += elementParent.scrollTop;
            }
            leftWidth+=elementParent.offsetLeft//+(elementParent.scrollWidth-elementParent.offsetWidth);
            elementParent = elementParent.offsetParent;
        };
        var x = control.offsetLeft+leftWidth+document.body.scrollLeft;
        var y = control.offsetHeight+topHeight+document.body.scrollTop;
        
        if(y+control.offsetHeight+scrollHeight>self.frameElement.offsetHeight)
            y = y-control.offsetHeight-control.style.posHeight;
            
        var p = {};
        p.x = x;
        p.y = y;
        return p;
    }
}

sg.get_sgAutoFilterById = function(id)
{
    return sg_AutoFilterState[id];
}

实现效果，先看看以下以下两个图

根据拼音检索

根据汉字检索

里面有几个重要的知识点，

1）dom的操作。

2）Function.createDelegate(this,this._handler) 或者用函数的闭包来实现。

3）该控件如果放在浮动的层中时设定弹出层的相对位置。

内容太多，页面不动了：），下篇分析！