C#后台创建控件并获取值的方法

<form id="form1" runat="server">
    <div>
        <div class="item">
            please input a number:
            <asp:textbox runat="server" cssclass="item" id="txttextcount"></asp:textbox>
          
            <asp:button runat="server" id="btncreate" text="create textbox list" validationgroup="createtextbox"
                onclick="btncreate_click" />  
            <asp:button runat="server" id="btnok" text="获取控件值" validationgroup="showlistcontent"
                onclick="btnok_click" />
        </div>
        <div runat="server" id="divcontrols" class="item">
        </div>
        <div runat="server" id="divmessage">
        </div>
    </div>
</form>

protected void page_load(object sender, eventargs e)
    {
        if (this.ispostback)
        {
            int txtcount = int.parse(txttextcount.text);

            // 注意：每次postback时，都需要重新动态创建textbox
            createtextboxlist(txtcount);
        }
    }
    ///<summary> 

    /// create textbox list
    ///</summary>
    ///<param name="num">textbox list count</param>
    private void createtextboxlist(int num)
    {
        htmlgenericcontrol div;
        htmlgenericcontrol span;
        textbox txt;
        //regularexpressionvalidator rev;

        for (int i = 0; i < num; i++)
        {
            //创建div
            div = new htmlgenericcontrol();
            div.tagname = "div";
            div.id = "divtextbox" + i.tostring();
            div.attributes["class"] = "item2";

            //创建span
            span = new htmlgenericcontrol();
            span.id = "spantextbox" + i.tostring();
            span.innerhtml = "url address" + (i + 1).tostring() + ":";

            //创建textbox
            txt = new textbox();
            txt.id = "txt" + i.tostring();
            txt.cssclass = "input";

            //创建格式验证控件，并且将其关联到对应的textbox
            //rev = new regularexpressionvalidator();
            //rev.id = "rev" + i.tostring();
            //rev.controltovalidate = txt.id;
            //rev.display = validatordisplay.dynamic;
            //rev.validationgroup = "showlistcontent";
            //rev.validationexpression = @"(http(s)?://)?([\w-]+\.)+[\w-]+(/[\w- ./?%&=]*)?";
            //rev.errormessage = "invalid url address!";

            //添加控件到容器
            div.controls.add(span);
            div.controls.add(txt);
            //div.controls.add(rev);
            divcontrols.controls.add(div);
        }
    }

    protected void btncreate_click(object sender, eventargs e)
    {
        txttextcount.enabled = false;
        btncreate.enabled = false;
    }

    protected void btnok_click(object sender, eventargs e)
    {
        textbox txt;
        htmlgenericcontrol span;
        stringbuilder sbresult = new stringbuilder();
        int txtcount = int.parse(txttextcount.text);

        //遍历获取动态创建的textbox们中的text值
        for (int i = 0; i < txtcount; i++)
        {
            //注意：这里必须通过上层容器来获取动态创建的textbox，才能获取取viewstate内容
            txt = divcontrols.findcontrol("txt" + i.tostring()) as textbox;

            if (txt != null && txt.text.trim().length > 0)
            {
                sbresult.appendformat("url address{0}: {1}.<br />", i + 1, txt.text.trim());
            }
        }
        //遍历获取动态创建的textbox们中的text值
        for (int i = 0; i < txtcount; i++)
        {
            //注意：这里必须通过上层容器来获取动态创建的textbox，才能获取取viewstate内容
            span = divcontrols.findcontrol("spantextbox" + i.tostring()) as  htmlgenericcontrol ;

            if (span != null && span.innertext.trim().length > 0)
            {
                sbresult.appendformat("url address{0}: {1}.<br />", i + 1, span.innertext.trim());
            }
        }
        divmessage.innerhtml = sbresult.tostring();
}