求助如何实现动态生成控件，然后获取值

Question

现在项目需要一个动态生成表单的功能

我一开始的实现如下

.aspx文件生成表单代码块

<table>

            <asp:Repeater ID="BrandList" runat="server">
                <ItemTemplate>
                    <tr>
                        <th>
                         <%#Eval("t_name") %>:
                        </th>
                                          <td>
                      <%#Eval("TypeName")%> : <%#out_table(int.Parse(Eval("Id").ToString()),
                      Eval("t_name").ToString(),Eval("inputType").ToString(),
                      Eval("xuanxiang").ToString(),
                      int.Parse(Eval("required").ToString()))%>
                        </td>
 
                    </tr>
                </ItemTemplate>
            </asp:Repeater>
    </table>

.aspx.cs文件生成表单代码块

 protected void Page_Load(object sender, EventArgs e)
    {
        
        thisGod = this;
        if (!IsPostBack)
        {
            if (!string.IsNullOrEmpty(Request.QueryString["id"].ToString()))
            {
                //int TypeId = setid();
                //box.TypeId = TypeId;
                //box.createTime = DateTime.Now;
                string wheresql = "TypeId = " + TypeId.ToString();
                this.BrandList.DataSource = DAL.tableType.GetList(wheresql);
                this.BrandList.DataBind();
            }
        }
    }

    public string out_table(int ControlId, string t_name, string inputType, string xuanxiang,int required)
    {
        box.List.Add(new tableBase() { name = (t_name +"_"+ ControlId.ToString()),Value  = "",ControlId = ControlId});
        string inputstring = "";
        if (inputType == "text")
        {
            inputstring = "<input id=\"" + t_name + "_" + ControlId + "\""  + " type=\"text\" runat=\"server\" ";
            if (required == 1) 
            {
                inputstring += "required=\"required\" ";
            }
            inputstring += "/>";
            
        }
        if (inputType == "textarea")
        {
            inputstring = "<textarea  id=\"" + t_name + "_" + ControlId + "\"" + " type=\"text\" runat=\"server\" ";
            if (required == 1)
            {
                inputstring += "required=\"required\" ";
            }
            inputstring += "style=\"width: 300px; height: 200px\" ></textarea> ";
        }
        if (inputType == "select")
        {
            inputstring = "<select id=\"" + t_name +  "_" + ControlId + "\""  + " runat=\"server\" ";
            if (required == 1)
            {
                inputstring += "required=\"required\" "; 
            }
            inputstring += "/>";
            string[] split = xuanxiang.Split(new Char[] { '|' });
            foreach (string s in split)
            {

                if (s.Trim() != "")
                    inputstring += "<option value=\"" + s + "\">" + s + "</option> ";

                
            }
            inputstring += "</select>";
        }
            return inputstring;
        
    }

.aspx提交表单按键代码块

<asp:Button ID="Button1" runat="server" Text="确定" OnClick="Button1_Click" />

.aspx.cs提交表单按键代码块

  protected void Button1_Click(object sender, EventArgs e)
    {
        //System.Collections.Specialized.NameValueCollection nc = new System.Collections.Specialized.NameValueCollection(Request.Form);
        //nc.GetValues("111_1")[0].ToString();
        //Request.Form.GetValues("111_1");
        //Request.Form.GetValues("222_2");
        //Request.Form.GetValues("333_3");
        //Request.Form.GetValues("55_4");   

        getAllControlValue(this);
        //SetTable_mg();
    }

  Hashtable getAllControlValue(object PageOrUserControl)
    {
        Hashtable rtn = new Hashtable();

        foreach (Control ctr in (PageOrUserControl as Page).Controls)
        {
            getControlValue(ctr, rtn);
        }
        Page.ClientScript.RegisterStartupScript(GetType(), "", "<script>alert('已提交')</script>");
        return rtn;
    }
    void getControlValue(Control ctrIn, Hashtable ht)
    {
        DateTime Date = DateTime.Now;
        foreach (Control ctr in ctrIn.Controls)
        {
            int ControlId = 0;
            string value = "";
            Type controlType = ctr.GetType();

            switch (controlType.ToString())
            {
                case "System.Web.UI.HtmlControls.HtmlInputText":
                    HtmlInputText controlTextObj = (HtmlInputText)ctr;
                    ControlId = GetControlId(controlTextObj.ID);
                    value = controlTextObj.Value;
                    break;
                case "System.Web.UI.HtmlControls.HtmlTextArea":
                    HtmlTextArea controlAreaObj = (HtmlTextArea)ctr;
                    ControlId = GetControlId(controlAreaObj.ID);
                    value = controlAreaObj.Value;
                    break;
                case "System.Web.UI.HtmlControls.HtmlSelect":
                    HtmlSelect controlSelectObj = (HtmlSelect)ctr;
                    ControlId = GetControlId(controlSelectObj.ID);
                    value = controlSelectObj.Value;
                    break;
                //case "其他类型":
                //    其它类型 controlTextBoxObj = (其它类型)ctr;
                //    string controlTextBoxName = controlTextBoxObj.ID;
                //    string controlTextBoxValue = controlTextBoxObj.Text;
                //    ht.Add(controlTextBoxName, controlTextBoxValue);
                //    break;
                default:
                    break;
            }
            if (ControlId != 0)
            {
                Model.table_mg model = new Model.table_mg();
                model.ControlId = ControlId;
                model.t_Value = value;
                model.createTime = Date;
                DAL.table_mg.Add(model);
            }
        }
        
    }

经过调试发现无法获得动态生成控件(HtmlText,HtmlSelect,HtmlArea)里的Value

于是查看msdn文档:

如何：以编程方式向 ASP.NET 网页添加控件

PlaceHolder 类

Control.Controls 属性

BaseDataList.SelectedIndexChanged 事件

复制上面几个文档里的代码写了如下的测试小程序

aspx.cs生成动态控件代码

 <asp:DropDownList ID="DropDownList1" runat="server" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" AutoPostBack="True">
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
        </asp:DropDownList>
        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
        <asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>

aspx.cs动态生成控件代码

        protected void DropDownList1_SelectedIndexChanged(object sender,System.EventArgs e)
        {
            //DropDownList DropDownList1 = new DropDownList();
            //PlaceHolder PlaceHolder1 = new PlaceHolder();

            // Get the number of labels to create.
            int numlabels = System.Convert.ToInt32(this.DropDownList1.SelectedItem.Text);
            for (int i = 1; i <= numlabels; i++)
            {
                Label myLabel = new Label();

                // Set the label's Text and ID properties.
                myLabel.Text = "Label" + i.ToString();
                myLabel.ID = "Label" + i.ToString();
                this.PlaceHolder1.Controls.Add(myLabel);
                // Add a spacer in the form of an HTML <br /> element.
                this.PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
            }
        }

aspx获取动态控件代码

 <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />

aspx.cs获得动态控件代码

 protected void Button1_Click(object sender, EventArgs e)
        {
            getAllControlValue(this);
        }

        Hashtable getAllControlValue(object PageOrUserControl)
        {
            Hashtable rtn = new Hashtable();

            foreach (Control ctr in (PageOrUserControl as Page).Controls)
            {
                getControlValue(ctr, rtn);
            }

            return rtn;
        }

        void getControlValue(Control ctrIn, Hashtable ht)
        {
            //foreach (Control ctr in ctrIn.Controls)
            foreach (Control ctr in this.PlaceHolder1.Controls)
            {
                Type controlType = ctr.GetType();

                switch (controlType.ToString())
                {
                    case "System.Web.UI.WebControls.Label":
                        Label LabelObj = (Label)ctr;
                        string LabelName = LabelObj.ID;
                        string LabelText = LabelObj.Text;
                        break;
                    //case "System.Web.UI.HtmlControls.HtmlInputText":
                    //    HtmlInputText controlInputTextObj = (HtmlInputText)ctr;
                    //    string controlInputTextName = controlInputTextObj.ID;
                    //    string controlInputTextValue = controlInputTextObj.Value;
                    //    ht.Add(controlInputTextName, controlInputTextValue);
                    //    break;
                    //case "System.Web.UI.HtmlControls.HtmlTextArea":
                    //    HtmlTextArea controlHtmlAreaObj = (HtmlTextArea)ctr;
                    //    string controlHtmlAreaName = controlHtmlAreaObj.ID;
                    //    string controlHtmlAreaValue = controlHtmlAreaObj.Value;
                    //    ht.Add(controlHtmlAreaName, controlHtmlAreaValue);
                    //    break;
                    //case "System.Web.UI.HtmlControls.HtmlSelect":
                    //    HtmlSelect controlHtmlSelectObj = (HtmlSelect)ctr;
                    //    string controlHtmlSelectName = controlHtmlSelectObj.ID;
                    //    string controlHtmlSelectValue = controlHtmlSelectObj.Value;
                    //    ht.Add(controlHtmlSelectName, controlHtmlSelectValue);
                    //    break;
                    //case "其他类型":
                    //    其它类型 controlTextBoxObj = (其它类型)ctr;
                    //    string controlTextBoxName = controlTextBoxObj.ID;
                    //    string controlTextBoxValue = controlTextBoxObj.Text;
                    //    ht.Add(controlTextBoxName, controlTextBoxValue);
                    //    break;
                    default:
                        break;
                }
            }
        }

但是经过调试，发现在生成阶段PlaceHolder控件里的Controls里面Count是有数值的，但是当代码进行到获取阶段PlaceHolder控件里的Controls里面Count变成0

我想求助，大家，如何改进代码获取动态生成控件的value值，，

Answer 1

你好，

因为你每次点击button,会发生postback,而你的动态控件数据会丢失。

所以每次，你会发现controls的Count为0.

当你把创建动态控件的过程放在

protected override void OnInit(EventArgs e)
{

    createDynamicControl();//在OnInit中执行动态添加控件的方法，这样就会保存其状态视图

｝

你可以参考下面的链接

http://www.cnblogs.com/vihone/archive/2010/01/06/1640025.html