点击下拉选择触发事件【c#】

 <asp:DropDownList ID="ddlRegionList" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlDeptList_SelectedIndexChanged">
                        <asp:ListItem>是</asp:ListItem>
                        <asp:ListItem>否</asp:ListItem>
                    </asp:DropDownList>
 
 protected void ddlDeptList_SelectedIndexChanged(object sender, EventArgs e)
        {
 
  code.....
            FillDG();
            FillUI();
        }