Asp.net中用戶自定義控件ascx的使用

使用ascx目的就是為了提高某部分功能的重復利用，我簡單通過源代碼說一下對它的參數的輸入和數出。

我們以省市區三級連動為例子。

vs2005下ascx頁面的代碼：

<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>