转:GridView翻页时保存模板列内的RadioButtonList选择状态

最近用.NET做一个项目时，发现GridView翻页时，模板列内的RadioButtonList所选择的项不能保存。在网上搜了一下解决方法，发现大都是模板列内是Checkbox的，RadioButtonList的很少。其实这两个的原理是一样的，要解决这个问题，核心就是写两个方法，分别是保存状态和还原状态，然后在GridView的翻页事件(GridView1_PageIndexChanging)里分别调用这两个方法。代码如下：

//保存RadioButtonList选择的项
protected void Save()
{       
        Hashtable ht = new Hashtable();           //实例化一个Hashtable,用于储存RadioButtonList选中的值。

        for (int i = 0; i < this.GridView1.Rows.Count; i++)    //循环GridView每一行
        {
            int id = Convert.ToInt32(this.GridView1.DataKeys[i].Value.ToString());   //获取GridView每一行对应的id
            RadioButtonList rbtn = (RadioButtonList)this.GridView1.Rows[i].FindControl("rbtnMatter");
            int matter = Convert.ToInt32(rbtn.SelectedValue);   

            if (ViewState["ht"] != null)
            {
                ht = (Hashtable)ViewState["ht"];
                if (ht.Contains(id))
                {
                    ht.Remove(id);
                }           
            }         
            ht.Add(id, matter);
            ViewState["ht"] = ht;
        }
}

//还原RadioButtonList选择的项
    protected void Revert()
    {
        Hashtable ht = (Hashtable)ViewState["ht"];
        for (int i = 0; i < this.GridView1.Rows.Count; i++)
        {
            int id = Convert.ToInt32(this.GridView1.DataKeys[i].Value.ToString());
            if (ht.Contains(id))
            {
                int matter = (int)ht[id];
                RadioButtonList rbtn = (RadioButtonList)this.GridView1.Rows[i].FindControl("rbtnMatter");
                rbtn.SelectedIndex = matter;
            }
        }
    }

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
        Save();
        this.GridView1.PageIndex = e.NewPageIndex;
        GridViewBind();
        Revert();
}