Asp.net中用户自定义控件ascx的使用

使用ascx目的就是为了提高某部分功能的重复利用，我简单通过源代码说一下对它的参数的输入和数出。

我们以省市区三级连动为例子。

vs2005下ascx页面的代码：

<table width="100%" border="0" cellpadding="0" cellspacing="0">      <tr>          <td>            <asp:DropDownList id="ddlProvince" runat="server" Width="100px" AutoPostBack="True" OnSelectedIndexChanged="ddlProvince_SelectedIndexChanged">            </asp:DropDownList>            <asp:UpdatePanel ID="UpdatePanel1" runat="server" RenderMode="Inline">                  <ContentTemplate>                    <asp:DropDownList id="ddlCity" runat="server" Width="100px" AutoPostBack="True" OnSelectedIndexChanged="ddlCity_SelectedIndexChanged">                    </asp:DropDownList>                  </ContentTemplate>                <Triggers>                    <asp:AsyncPostBackTrigger ControlID="ddlProvince" EventName="SelectedIndexChanged" />                </Triggers>              </asp:UpdatePanel>              <asp:UpdatePanel ID="UpdatePanel2" runat="server" RenderMode="Inline">                  <ContentTemplate>                    <asp:DropDownList id="ddlDistrict" runat="server" Width="100px">                     </asp:DropDownList>                  </ContentTemplate>                  <Triggers>                      <asp:AsyncPostBackTrigger ControlID="ddlCity" EventName="SelectedIndexChanged" />                  </Triggers>              </asp:UpdatePanel>          </td>      </tr>  </table>