C# mvc下拉列表不显示所选索引

我的控制器上有以下各项：

string preferredLanguage = "fr-ca";
ViewData["Languages"] = new SelectList(languages, "Code", "Name", preferredLanguage);

关于这一观点：

@Html.DropDownList("Languages", (SelectList)ViewData["Languages"], new { id = "Languages" });

我的问题是，我的下拉列表没有将所选的下拉列表索引设置为首选语言，即法语

注:

语言中的值

：

1) Name = "English"
   Code = "en-us"

2) Name = "French"
   Code = "fr-ca"

下拉列表显示两种语言，英语和法语。英语被设置为选定的索引，但我想要的是法语

---

我之所以以这种方式显示

语言

，是因为此对象是通过我的方法从数据库中检索的，而不是通过硬编码。提前谢谢

这对我来说很有效

Dictionary<string, string> languages = new Dictionary<string, string>() { { "en-us", "English" }, { "fr-ca", "French" } };
ViewData["Languages"] = new SelectList(languages, "key", "value", "fr-ca");

---

我建议使用绑定到模型的强类型助手；大致如下：

型号：

public class LanguageFormModel
{
    public string SelectedLanguage { get; set; }

    public SelectList Languages { get; set; }
}

[HttpGet]
public ActionResult YourActionName()
{
    // replace this with however you're getting your language variable
    var languages = new CollectionOfSomeSort();

    var model = new LanguageFormModel()
    {
        SelectedLanguage = "fr-ca",
        Languages = new SelectList(languages, "Code", "Name", "fr-ca")
    };

    return View(model);
}

@model Your.Fully.Qualified.Namespace.LanguageFormModel

@Html.LabelFor(m => m.SelectedLanguage)
@Html.DropDownListFor(m => m.SelectedLanguage, Model.Languages, "Select one...")

行动：

public class LanguageFormModel
{
    public string SelectedLanguage { get; set; }

    public SelectList Languages { get; set; }
}

[HttpGet]
public ActionResult YourActionName()
{
    // replace this with however you're getting your language variable
    var languages = new CollectionOfSomeSort();

    var model = new LanguageFormModel()
    {
        SelectedLanguage = "fr-ca",
        Languages = new SelectList(languages, "Code", "Name", "fr-ca")
    };

    return View(model);
}

@model Your.Fully.Qualified.Namespace.LanguageFormModel

@Html.LabelFor(m => m.SelectedLanguage)
@Html.DropDownListFor(m => m.SelectedLanguage, Model.Languages, "Select one...")

查看：

public class LanguageFormModel
{
    public string SelectedLanguage { get; set; }

    public SelectList Languages { get; set; }
}

[HttpGet]
public ActionResult YourActionName()
{
    // replace this with however you're getting your language variable
    var languages = new CollectionOfSomeSort();

    var model = new LanguageFormModel()
    {
        SelectedLanguage = "fr-ca",
        Languages = new SelectList(languages, "Code", "Name", "fr-ca")
    };

    return View(model);
}

@model Your.Fully.Qualified.Namespace.LanguageFormModel

@Html.LabelFor(m => m.SelectedLanguage)
@Html.DropDownListFor(m => m.SelectedLanguage, Model.Languages, "Select one...")

我个人不太喜欢使用

ViewData

来处理简单的消息以外的任何事情，即使这样，我也会使用

TempData

，因为我主要只是显示确认/警报。

这没问题：

@Html.DropDownList("languages")

---

谢谢，但我现在正在使用第一个。请参阅我的代码更新。谢谢这很奇怪。我更新了我的代码，我们现在有相同的，但我的不工作。可能遗漏了什么。我的视图中已经有一个强类型对象，它不包括语言列表，只包括他想要的语言。但这帮我解决了我的问题，做了最后一行你的看法。谢谢