AJAX控件的简单使用

 <div>
   <asp:UpdatePanel ID="upp1" runat="server">
     <ContentTemplate>
       <asp:ScriptManager ID="sm" runat="server">
            
       </asp:ScriptManager>
       <asp:Calendar runat="server" ID="cld"></asp:Calendar>
       
       <br />
         <asp:DropDownList ID="DropDownList1" runat="server" runat="server" 
             AutoPostBack="true" 
             onselectedindexchanged="DropDownList1_SelectedIndexChanged" >
          <asp:ListItem Value="Red" >红色</asp:ListItem>
          <asp:ListItem Value="Blue" >蓝色</asp:ListItem>
         </asp:DropDownList>
       
       
       
     </ContentTemplate>
       
   </asp:UpdatePanel>
</div>



 protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {
            cld.DayStyle.BackColor = System.Drawing.Color.FromName(DropDownList1.SelectedItem.Value);
        }