Asp.Net RadioButtonList選擇的ListItem頁面上不能識別

Question

在我的收貨地址頁面上有兩個RadioButtonList ListItems（下面顯示的代碼）根據用戶輸入寫入數據庫true或false。

用戶第一次選擇一個值並轉到結帳過程的下一步時，他們的發貨地址類型會正確存儲在數據庫中（true/false）。如果他們返回送貨地址頁面，請選擇相反的ListItem並轉到下一個結賬頁面，其更新的送貨類型在數據庫中不會更改。就好像ListItem不能識別用戶的單選按鈕選擇在重新訪問頁面時已經改變。

有人可以幫忙解決這個問題嗎？

ShippingAddress.ascx

<asp:RadioButtonList id="ShipToAddressType" runat="server"> 
    <asp:ListItem Value="0" id="businessShipping">My shipping address is a business.</asp:ListItem> 
    <asp:ListItem Value="1" id="residenceShipping">My shipping address is a residence.</asp:ListItem> 
</asp:RadioButtonList> 

ShippingAddress.ascx.cs

if (residenceShipping.Selected == true) 
    shippingAddress.Residence = true; 
else 
    shippingAddress.Residence = false; 

ShippingAddress.ascx.cs的Page_Load

protected void Page_Load(object sender, EventArgs e) 
{ 
    User user = Token.Instance.User; 

    Address shipAddress = null; 

    foreach (Address tempAddress in user.Addresses) if (tempAddress.Nickname == "Shipping") shipAddress = tempAddress; 

    // sets radio button of return users previously selected ship type 
    if (shipAddress != null) 
    { 
     if (shipAddress.Residence == false) 
     { 
      ShipToAddressType.SelectedIndex = 0; 
     } 
     else 
     { 
      ShipToAddressType.SelectedIndex = 1; 
     } 
    } 
} 

Answer 1

您需要將Page_Load中的代碼移至Page_Init。否則ViewState將不起作用，您不會收到更改事件。視圖狀態在PreLoad之前的Init之後加載。

您還應該將您的init代碼包裝在IsPostBack檢查中。儘管我可能會誤解你在這裏做什麼。

protected void Page_Init(EventArgs e) 
{ 
    if (!IsPostBack) 
    { 
     User user = Token.Instance.User; 

     Address shipAddress = null; 

     foreach (Address tempAddress in user.Addresses) 
     { 
      if (tempAddress.Nickname != "Shipping") 
      { 
       continue; 
      } 
      ShipToAddressType.SelectedIndex = 1; 
     } 
    } 
    ShipToAddressType.SelectedIndexChanged += ShipToAddressType_SelectedIndexChanged; 
} 

void ShipToAddressType_SelectedIndexChanged(object sender, EventArgs e) 
{ 
    // save the new state to database 

    // redirect to enforce refresh of saved state 
    Response.Redirect(Request.RawUrl); 
}