后臺代碼:

2. ddlCity.DataBind();
3. }

.aspx代碼

1. <asp:UpdatePanelID="UpdatePanel1"runat="server">
2. <ContentTemplate>
3. <asp:DropDownListID="ddlProvince"runat="server"AutoPostBack="True"
4. onselectedindexchanged="ddlProvince_SelectedIndexChanged">
5. </asp:DropDownList>
6. <asp:DropDownListID="ddlCity"runat="server">
7. </asp:DropDownList>
8. <asp:ButtonID="Button1"runat="server"onclick="Button1_Click"Text="Button"/>
9. <br/>
10. <br/>
11. <br/>
12. <asp:LabelID="Label1"runat="server"Text="Label"></asp:Label>
13. </ContentTemplate>
14. </asp:UpdatePanel>

訪問速度很慢,,,...

第一步要添加Web引用

然后頁面就有東西了.....webServices給的很明確了