在LoadPostData里如何取得数据

[xjgsina]

我的dropdownlist控件在Render里重写了，所以取值如SelectedValue需要在LoadPostData里取，但dropdownlist控件只回发一个值SelectedValue。而SelectedItem和SelectedIndex均为空。在LoadPostData里dropdownlist数据也为空。怎么样样才能取到SelectedItem和SelectedIndex？？

    protected override void Render(HtmlTextWriter output)
        {
                string DDLValue;
                string DDLText;

                output.Write("<div  class=\"ui-widget\">");
                _ddlSource = (DataTable)ViewState["AutoListDataSource"];
                _valueKeyName = (string)ViewState["AutoListValueKeyName"];
                _textKeyName = (string)ViewState["AutoListTextKeyName"];
                _isShowDetailed = (bool)ViewState["AutoListShowDetailed"];

                if (_ddlSource != null)
                {
                    if (_ddlSource.Rows.Count > 0)
                    {
                        foreach (DataRow dr in _ddlSource.Rows)
                        {
                            DDLValue = String.IsNullOrEmpty(_valueKeyName) == true ? dr[0].ToString() : dr[_valueKeyName].ToString();
                            DDLText = String.IsNullOrEmpty(_textKeyName) == true ? dr[1].ToString() : dr[_textKeyName].ToString();

                            ListItem li = new ListItem();
                            if (_isShowDetailed == true)
                            {
                                li.Text = DDLValue + "|" + DDLText;
                            }
                            else
                            {
                                li.Text = DDLValue;
                            }
                            li.Value = DDLValue;
                            this.Items.Add(li);

                        }

                    }
                    if (this.Items.Count > 0)
                    {
                        this.Items.Insert(0, new ListItem("", ""));
                    }
                    if (ViewState["AutoListSelectValue"] != null)
                    {
                        this.Items.FindByValue((string)ViewState["AutoListSelectValue"]).Selected = true;
                    }
                }
                base.Render(output);
                output.Write("</div>");
                
        }

    public virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection)
        {
            string[] postDataValues = postCollection.GetValues(postDataKey);
            if (postDataValues != null)
            {
                this.SelectedValue = postDataValues[0];
                if (this.SelectedValue != null && (postDataValues[0] != null && !this.SelectedValue.Equals(postDataValues[0])))
                { 
                    this.SelectedValue = postDataValues[0];
                    ViewState["AutoListSelectValue"] = this.SelectedValue;
                    return true; 
                }
            }
            else
            {
                return false;
            }
            return false;

        }

[冰镇宝贝321]

http://www.cnblogs.com/cathsfz/archive/2006/10/22/536425.html

[xjgsina]

[Quote=引用 1 楼 的回复:]
http://www.cnblogs.com/cathsfz/archive/2006/10/22/536425.html
[/Quote]
思路有点复杂了，看的不是很明白