改变主题

Question

我通过DropDownList选择主题，由于当OnPreInit(EventArgs s)执行完后，ddlTheme_SelectedIndexChanged(object sender, EventArgs e)迟迟才执行，导致选择的主题不能立即生效，只有刷新后才生效，怎样使我选择DropDownList后主题立即生效？前台代码
<asp:DropDownList ID="ddlTheme" runat="server" OnSelectedIndexChanged="ddlTheme_SelectedIndexChanged" AutoPostBack="True">
     <asp:ListItem Value"Default">默认主题</asp:ListItem>
     <asp:ListItem Value="New">新主题</asp:ListItem>
</asp:DropDownList>后台代码
 private static string theme = "Default";
 protected override void OnPreInit(EventArgs e)
    {
        base.OnPreInit(e);
        this.Theme = theme;
                              
    }
protected void ddlTheme_SelectedIndexChanged(object sender, EventArgs e)
    {
        theme = ddlTheme.SelectedValue;
              
    }

Answer 1

protected void ddlTheme_SelectedIndexChanged(object sender, EventArgs e)
  {
  theme = ddlTheme.SelectedValue;
    repnose.redict("指向当前页面，将页面重定向一下");
  }

Answer 2

protected override void Render(HtmlTextWriter writer)
{
}
试试

Answer 3

protected void ddlTheme_SelectedIndexChanged(object sender, EventArgs e)
  {
  theme = ddlTheme.SelectedValue;
    Response.Redirect(""）；
  }

Answer 4

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
    var a= this.Response.Cookies["theme"];
    a.Value = this.DropDownList1.SelectedValue;
    a.Expires = DateTime.MaxValue;
    Response.Redirect(Request.RawUrl);   
}