DropDownList.SelectedValue不正確

Question

我在UserControl中有下列dropdwonlists;

<span class="src-engine-row-title-span">ADT : </span> 
      <asp:DropDownList runat="server" ID="ddlAdultTrf"></asp:DropDownList> 

      <span class="src-engine-row-title-span">CHD : </span> 
      <asp:DropDownList runat="server" ID="ddlChildrenTrf"></asp:DropDownList> 

      <span class="src-engine-row-title-span">INF : </span> 
      <asp:DropDownList runat="server" ID="ddlInfantTrf"></asp:DropDownList> 

我正在使用下面的代碼在page_load事件上爲它們分配值;

ddlAdultTrf.DataTextField = "FieldName"; 
ddlAdultTrf.DataValueField = "FieldValue"; 
ddlAdultTrf.DataSource = repo.AdultsForTransferSearch(); 
ddlAdultTrf.DataBind(); 

ddlInfantTrf.DataTextField = "FieldName"; 
ddlInfantTrf.DataValueField = "FieldValue"; 
ddlInfantTrf.DataSource = repo.ChildrenForTransferSearch(); 
ddlInfantTrf.DataBind(); 

ddlChildrenTrf.DataTextField = "FieldName"; 
ddlChildrenTrf.DataValueField = "FieldValue"; 
ddlChildrenTrf.DataSource = repo.InfantsForTransferSearch(); 
ddlChildrenTrf.DataBind(); 

這裏是生成的下拉列表標記;

  <span class="src-engine-row-title-span">ADT : </span> 
       <select name="ctl00$MainContent$SearchEngine$ddlAdultTrf" id="MainContent_SearchEngine_ddlAdultTrf"> 
    <option value="1">1</option> 
    <option value="2">2</option> 
    <option value="3">3</option> 
    <option value="4">4</option> 
    <option value="5">5</option> 
    <option value="6">6</option> 
    <option value="7">7</option> 
    <option value="8">8</option> 
    <option value="9">9</option> 
    <option value="10">10</option> 
    <option value="11">11</option> 
    <option value="12">12</option> 
    <option value="13">13</option> 
    <option value="14">14</option> 
    <option value="15">15</option> 
    <option value="16">16</option> 
    <option value="17">17</option> 
    <option value="18">18</option> 
    <option value="19">19</option> 
    <option value="20">20</option> 
    <option value="21">21</option> 
    <option value="22">22</option> 
    <option value="23">23</option> 
    <option value="24">24</option> 
    <option value="25">25</option> 
    <option value="26">26</option> 
    <option value="27">27</option> 
    <option value="28">28</option> 
    <option value="29">29</option> 
    <option value="30">30</option> 
    <option value="31">31</option> 
    <option value="32">32</option> 
    <option value="33">33</option> 
    <option value="34">34</option> 
    <option value="35">35</option> 
    <option value="36">36</option> 
    <option value="37">37</option> 
    <option value="38">38</option> 
    <option value="39">39</option> 
    <option value="40">40</option> 

</select> 

       <span class="src-engine-row-title-span">CHD : </span> 
       <select name="ctl00$MainContent$SearchEngine$ddlChildrenTrf" id="MainContent_SearchEngine_ddlChildrenTrf"> 
    <option value="0">0</option> 
    <option value="1">1</option> 
    <option value="2">2</option> 
    <option value="3">3</option> 
    <option value="4">4</option> 
    <option value="5">5</option> 
    <option value="6">6</option> 
    <option value="7">7</option> 
    <option value="8">8</option> 
    <option value="9">9</option> 
    <option value="10">10</option> 

</select> 

       <span class="src-engine-row-title-span">INF : </span> 
       <select name="ctl00$MainContent$SearchEngine$ddlInfantTrf" id="MainContent_SearchEngine_ddlInfantTrf"> 
    <option value="0">0</option> 
    <option value="1">1</option> 
    <option value="2">2</option> 
    <option value="3">3</option> 
    <option value="4">4</option> 
    <option value="5">5</option> 
    <option value="6">6</option> 
    <option value="7">7</option> 
    <option value="8">8</option> 
    <option value="9">9</option> 
    <option value="10">10</option> 

</select> 

當加載頁面時，我選擇從下拉列表的東西，我想從代碼中獲得的SelectedValue落後，但所選擇的值與所選擇的一個相同。

你知道這裏發生了什麼嗎？

Answer 1

放在以下條件語句中的Page_Load方法的代碼：

if (!Page.IsPostBack) 
{ 


}