用戶控件的下拉造成內部的UpdatePanel

Question

我工作在asp.net應用程序完全回發，我有一個更新面板是這樣的：

<asp:UpdatePanel ID="upCheckout" runat="server"> 
        <ContentTemplate> 
         <!-- BillingAddress --> 
         <div runat="server" id="pnlBillingAddress" class="checkoutstep"> 

          <asp:Panel runat="server" ID="pnlBillingAddressContent" class="stepcontent"> 
           <nopCommerce:CheckoutBillingAddress ID="ctrlCheckoutBillingAddress" runat="server" 
            OnePageCheckout="true" OnCheckoutStepChanged="ctrlCheckoutBillingAddress_CheckoutStepChanged" /> 


           <asp:CheckBox ID="chkShippingSameAsBilling" runat="server" Text=" Ship to same address" 
            AutoPostBack="true" Checked="true" onclick="ShowShippingAddress();" /><br /> 
          </asp:Panel> 
         </div> 
         <!-- ShippingAddress --> 
         <div runat="server" id="pnlShippingAddress" class="checkoutstep">         
          <asp:Panel runat="server" ID="pnlShippingAddressContent" class="stepcontent"> 
           <nopCommerce:CheckoutShippingAddress ID="ctrlCheckoutShippingAddress" runat="server" 
            OnePageCheckout="true" OnCheckoutStepChanged="ctrlCheckoutShippingAddress_CheckoutStepChanged" />          
          </asp:Panel> 
         </div> 
        </ContentTemplate> 
       </asp:UpdatePanel> 

其中的帳單地址的用戶控件。在帳單地址控制中，有一個下拉列表。像這樣：

<asp:DropDownList ID="drpBillingAddresses" ClientIDMode="Static" runat="server" AutoPostBack="True" OnSelectedIndexChanged="drpBillingAddresses_SelectedIndexChanged"> 
         </asp:DropDownList> 

但是當我改變下拉選擇，我得到完整的回發，而不是部分回發。爲什麼我得到全面回發？

Answer 1

通過設置UpdatePanel的Triggers屬性，將OnSelectedIndexChanged事件註冊爲異步事件。