FormView切换Mode为Edit时，用户控件的属性丢失？

Question

在用户控件中属性通过viewstate储存.
因为普通服务器控件是有VIEWSTATE自动存储机制的,用户控件还需你自己添加,
请把用户控件代码帖出来.

Answer 1

选择一个最简单的
<%@ Control Language="C#" AutoEventWireup="true"
    CodeFile="GenderSelect.ascx.cs" Inherits="BSE.Control.GenderSelect" %>
  <asp:DropDownList ID="myDropDownList" runat="server">
    <asp:ListItem Value="0">-</asp:ListItem>
    <asp:ListItem Value="1">男</asp:ListItem>
    <asp:ListItem Value="2">女</asp:ListItem>
  </asp:DropDownList>
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;using BSE.Common;
namespace BSE.Control
{
    public partial class GenderSelect : System.Web.UI.UserControl
    {
        private byte _value;        public byte Value
        {
            set
            {
                _value = value;
            }
            get
            {
                return _value;
            }
        }        protected void Page_Load(object sender, EventArgs e)
        {
            if (this.IsPostBack)
            {
                _value = BseFilter.GetByte(myDropDownList.SelectedValue);
            }
            else
            {
                myDropDownList.SelectedValue = (_value >= 0 && _value <= 2) ? _value.ToString() : "";
            }
        }
    }
}

Answer 2

1楼说的viewstate可能有道理，我马上去查查

Answer 3

        private byte _value;        public byte Value
        {
            set
            {
                _value = value;
            }
            get
            {
                return _value;
            }
        }==
        public byte Value
        {
            set
            {
                ViewState["myvalue"] = value;
            }
            get
            {
                object o = ViewState["myvalue"];
                if(o != null)
                {
                    return (byte)o;
                }
                return 0;
            }
        }