爲什麼在下拉列表中沒有選擇任何選項？

Question

我很困惑，爲什麼選擇列表中的相應選項沒有被選中。 當我通過循環，item.DisciplineId = 2，但學校沒有被選中（「選擇」仍然是）。有什麼建議麼 ？

查看

<% foreach (var item in Model.TeamMembers) 
{ %> 
<tr> 
    <td> 
     <%: Html.DropDownListFor(m => item.DisciplineId, Model.MemberDisciplines, "Choose") %> 
    </td> 
</tr> 
<% } %> 

視圖模型

public SelectList MemberDisciplines { get; set; } 
public IEnumerable<TeamMember> TeamMembers { get; set; }//Set from the model 

MemberDisciplines = new SelectList(new[] { 
       new SelectListItem{ Text = "Technical", Value = "1"}, 
       new SelectListItem{ Text = "School", Value = "2"}, 
       new SelectListItem{ Text = "Health", Value = "3"} 
      }, "Value", "Text"); 

Answer 1

好吧，我會那麼建議你MemberDisciplines財產轉換成一個方法具有以下內容：

public SelectList GetMemberDisciplines(object selectedValue) 
{ 
    return new SelectList(new[] { 
     new SelectListItem{ Text = "Technical", Value = "1"}, 
     new SelectListItem{ Text = "School", Value = "2"}, 
     new SelectListItem{ Text = "Health", Value = "3"} 
    }, "Value", "Text", selectedValue); 
} 

然後你在你的DropDownListFor中調用它如下：

<% for (int i = 0; i < Model.TeamMembers.Count; i++) { %> 
    <tr> 
     <td> 
      <%: Html.DropDownListFor(m => Model.TeamMembers[i].DisciplineId, Model.GetMemberDisciplines(Model.TeamMembers[i].DisciplineId), "Choose..")%> 
     </td> 
    </tr> 
<% } %>