这应该做的工作：

<script type="text/javascript">
    var ShowWelcomeMsg = @Html.Raw(Model.ShowWelcomeMsg);
</script>

您应该先序列化数据。相反，传递一个布尔值，你应该传递一个字符串使用JSON符号：

You should serialize first your data. Instead of passing a boolean, you should pass a string with json notation:

public class IndexViewModel
{
    public string ShowWelcomeMsg { get; set; }
}

为了序列化到JSON你应该做的：

In order to serialize to json you should do:

public ActionResult Index()
{
    var serializer = new JavaScriptSerializer();
    var vm = new IndexViewModel
    {
         ShowWelcomeMsg = serializer.Serialize(true)
    };
    return View(vm);
}

这样，你甚至可以序列化整个C＃对象，并把它作为在JavaScript中的任何其他对象。

This way you can even serialize a whole C# Object and use it as any other object in JavaScript.