asp.net-mvc - MVC 4 Razor の "for" ループのバグのようですか?

Question

Microsoft ASP.NET MVC 4 バージョン 4.0.30.506.0 を使用して MVC4 を作成しています。かみそりページ内に for ループがあり、ばかげたランタイム エラーが発生します。

これは私が書いたコードです：

@{
                    if (Model.IsAuction)
                    {
                        <li class="bc49">@Html.ActionLink("ABCD", "Search", "Home", new {city = "all", type = "auction", category = "all", keyword = "all", condition = "all", sort = "asc"})</li>
                    }
                    else
                    {
                        <li class="bc49">@Html.ActionLink("EFGH", "Search", "Home", new {city = "all", type = "product", category = "all", keyword = "all", condition = "all", sort = "asc"})</li>
                    }

                    int crumpsCount = 48;

                    for (int i = 0; i < Model.Categories.Count; i++)
                    {
                        className = "bc" + crumpsCount;

                        if (Model.IsAuction)
                        {
                            <li class="@className">@Html.ActionLink(Model.Categories[i].Title, "Search", "Home", new {city = "all", type = "auction", category = Model.Categories[i].Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }
                        else
                        {
                            <li class="@className">@Html.ActionLink(Model.Categories[i].Title, "Search", "Home", new {city = "all", type = "product", category = Model.Categories[i].Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }

                        crumpsCount--;
                    }
                }

Visual Studio 2012 で生成されたエラーは次のとおりです。

エラーは、ループが終了し、i の値が Model.Categories.Count と等しい後に発生します。コンパイラが Model.Categories[Model.Categories.Count] 値にアクセスしようとしているようです!

面白いことに、このコードを foreach ループに置き換えたり、for ループの直後に foreach ループを追加したりしても、コードは正しく実行され、for ループを通過します。

これは機能するコードです：

@{
                    if (Model.IsAuction)
                    {
                        <li class="bc49">@Html.ActionLink("ABCD", "Search", "Home", new {city = "all", type = "auction", category = "all", keyword = "all", condition = "all", sort = "asc"})</li>
                    }
                    else
                    {
                        <li class="bc49">@Html.ActionLink("EFGH", "Search", "Home", new {city = "all", type = "product", category = "all", keyword = "all", condition = "all", sort = "asc"})</li>
                    }

                    int crumpsCount = 48;

                    for (int i = 0; i < Model.Categories.Count; i++)
                    {
                        className = "bc" + crumpsCount;

                        if (Model.IsAuction)
                        {
                            <li class="@className">@Html.ActionLink(Model.Categories[i].Title, "Search", "Home", new {city = "all", type = "auction", category = Model.Categories[i].Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }
                        else
                        {
                            <li class="@className">@Html.ActionLink(Model.Categories[i].Title, "Search", "Home", new {city = "all", type = "product", category = Model.Categories[i].Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }

                        crumpsCount--;
                    }

                    foreach (CategoryInfo categoryInfo in Model.Categories)
                    {
                        className = "bc" + crumpsCount;

                        if (Model.IsAuction)
                        {
                            <li class="@className">@Html.ActionLink(categoryInfo.Title, "Search", "Home", new {city = "all", type = "auction", category = categoryInfo.Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }
                        else
                        {
                            <li class="@className">@Html.ActionLink(categoryInfo.Title, "Search", "Home", new {city = "all", type = "product", category = categoryInfo.Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }

                        crumpsCount--;
                    }
                }

このコードを共有して、これがバグであるかどうかを確認し、バグである場合は既知のものであるかどうかを確認しました。

みんなありがとう。:)

更新: それはばかげています。コードは foreach ループでも機能しません!

foreach ループ内にインデックス作成はありませんが、インデックスが範囲外であることが例外で示されます。

コードは次のとおりです。

foreach (CategoryInfo categoryInfo in Model.Categories)
                    {
                        className = "bc" + crumpsCount;

                        if (Model.IsAuction)
                        {
                            <li class="@className">@Html.ActionLink(categoryInfo.Title, "Search", "Home", new {city = "all", type = "auction", category = categoryInfo.Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }
                        else
                        {
                            <li class="@className">@Html.ActionLink(categoryInfo.Title, "Search", "Home", new {city = "all", type = "product", category = categoryInfo.Name, keyword = "all", condition = "all", sort = "asc"})</li>
                        }

                        crumpsCount--;
                    }

また、Model.Categories は IList<> オブジェクトであることにも言及する必要があります。