asp.net MVC - 奇異指數超出範圍的Razor視圖ONLY

Question

我得到通過我的視圖模型的字典屬性進行遍歷時，一個奇怪的「索引超出範圍」例外迭代字典時，這是簡單的INT重點和對象的價值列表。這很奇怪，因爲只有在Razor視圖中迭代字典時纔會發生異常。只是爲了我自己的理智，我在控制器中運行了完全相同的迭代過程，沒有任何問題。這裏是代碼爲：

 Debug.WriteLine("+++++++++++++++++++++++++++++"); 
     for (int i = 0; i < viewModel.PhaseTemplateDict.Keys.Count(); i++) 
     { 
      Debug.WriteLine("Phase Name: " + viewModel.PhaseTemplateDict.Values.ElementAt(i)[0].ProgramLevelName); 
      Debug.WriteLine(""); 

      for (int j = 0; j < viewModel.PhaseTemplateDict.Values.ElementAt(i).Count(); j++) 
      { 
       Debug.WriteLine("Goal Name: " + viewModel.PhaseTemplateDict.Values.ElementAt(i)[j].GoalDescription);      
      } 
      Debug.WriteLine("========================="); 
     } 
     Debug.WriteLine("+++++++++++++++++++++++++++++"); 

這產生所需的輸出，沒有例外。

+++++++++++++++++++++++++++++ 
Phase Name: Orientation 

Goal Name: Provider 
Goal Name: UAs 
Goal Name: P.O. Meeting 
Goal Name: Provider Assessment 
Goal Name: Court 
========================= 
Phase Name: Phase 1 

Goal Name: School/Work 
Goal Name: Treatment 
Goal Name: Curfew Checks 
Goal Name: PO Meetings 
Goal Name: UAs 
Goal Name: Court 
========================= 
Phase Name: Phase 2 

Goal Name: test1 
Goal Name: test2 
========================= 
Phase Name: Phase 3 

Goal Name: test1 
Goal Name: test2 
Goal Name: test3 
Goal Name: test4 
========================= 
+++++++++++++++++++++++++++++ 

然而，當我使用幾乎相同的結構，我的Razor視圖來建一個表，我得到一個「System.ArgumentOutOfRangeException - 索引超出範圍。必須是非負值且小於集合的大小'。查看：

@model MyApp.ViewModels.PhaseTemplatesViewModel 

@using (Html.BeginForm("MyAction", "MyController", FormMethod.Post)) 
{ 
    @Html.AntiForgeryToken() 
    <div class="row"> 
     <div class="col-md-offset-3 col-md-5"> 
      @{ int index = 0;} 
      @for (int i = 0; i < Model.PhaseTemplateDict.Keys.Count(); i++) 
      { 
       <div class="row"> 
        <div class="panel panel-info"> 
         <div class="panel-heading"> 
          <h3 class="panel-title">@Model.PhaseTemplateDict.Values.ElementAt(i)[0].ProgramLevelName</h3> 
         </div> 
         <div class="panel-body"> 
          <table class="table table-striped table-hover"> 
           <thead> 
            <tr>           
             <th>Description</th> 
             <th>Points Required</th> 
             <th>Display Order</th> 
            </tr> 
           </thead> 
           <tbody> 
            @for (int j = 0; j < @Model.PhaseTemplateDict.Values.ElementAt(i).Count(); j++) 
            {           
             @Html.HiddenFor(mdlItem => @Model.PhaseTemplateDict.Values.ElementAt(i)[j].PointMatrixTemplateID, new { Name = "[" + index + "]." + "PointMatrixTemplateID" }) 
             @Html.HiddenFor(mdlItem => @Model.PhaseTemplateDict.Values.ElementAt(i)[j].ProgramLevel, new { Name = "[" + index + "]." + "ProgramLevel" }) 

             <tr> 
              <td> 
               @Html.TextBoxFor(mdlItem => @Model.PhaseTemplateDict.Values.ElementAt(i)[j].GoalDescription, new { @class = "form-control", Name = "[" + index + "]." + "GoalDescription" }) 
              </td> 
              <td> 
               @Html.TextBoxFor(mdlItem => @Model.PhaseTemplateDict.Values.ElementAt(i)[j].PointsRequired, new { @class = "form-control text-center", style = "width: 40px; padding: 0px", type = "number", Name = "[" + index + "]." + "PointsRequired" }) 
              </td> 
              <td> 
               @Html.TextBoxFor(mdlItem => @Model.PhaseTemplateDict.Values.ElementAt(i)[j].DisplayOrder, new { @class = "form-control text-center", style = "width: 40px; padding: 0px", type = "number", Name = "[" + index + "]." + "DisplayOrder" }) 
              </td> 
             </tr> 
             index++; 
            } 
           </tbody> 
          </table> 
         </div> 
         <div class="panel-footer"> 
          <button class="btn btn-primary" type="button" onclick="addGoalToTemplate(@Model.PhaseTemplateDict.Values.ElementAt(i)[i].ProgramLevel)">Add Goal</button> 
          <button class="btn btn-success" type="submit">Save</button>       
         </div> 
        </div> 
       </div> 
      } 
     </div> 
    </div> 

} 

在這種情況下，只要執行次數達到第三次內循環的頂部，就會發生異常。這是關鍵[2]（上面的'第二階段'）。當列表的長度（字典值）大於或等於映射到的字典鍵的索引時，我已能夠成功地呈現視圖。例如，在上面的調試輸出，「2階段」是在第3密鑰索引[2]，但其值列表只具有2的計數，所以發生異常。奇怪的是，如果我讓價值清單有3或更多的計數，一切工作正常。我一直在抓我的頭在這個一期一會，所以任何見解，爲什麼發生這種情況，將不勝感激。

Answer 1

韋爾普，我感覺很笨。

錯字上此按鈕的索引而引起的問題

<button class="btn btn-primary" type="button" onclick="addGoalToTemplate(@Model.PhaseTemplateDict.Values.ElementAt(i)[i].ProgramLevel)">Add Goal</button> 

應該是：

<button class="btn btn-primary" type="button" onclick="addGoalToTemplate(@Model.PhaseTemplateDict.Values.ElementAt(i)[0].ProgramLevel)">Add Goal</button> 

我只是改變了索引上從 '的ElementAt'（I）[I]至（ ⅰ）[0]。