c# - 如何在 PartialViews 内连接使用 HtmlHelper 扩展生成的 JavaScript 并添加到父 View ？

Question

我在父 View 中有 2 个 PartialView。

在这 2 个 PartiaView 中，我生成了一些 JavaScript 代码，需要将其包含在父 View 的底部。

这是 HtmlHelper 扩展，它在 PartialViews 中生成一些 JavaScript。

public static MvcHtmlString KO_ObjectFor<TModel>(this HtmlHelper<TModel> htmlHelper)
{
    String str = "some javascript code";
    return MvcHtmlString.Create(str);
}

这是父View(主View)

...
//First Partial View
<% Html.RenderPartial("_PartialViewFirst"); %>

//Second Partial View
<% Html.RenderPartial("_PartialViewSecond"); %>

//Here I need to display the JavaScript from the PartialViews
<script type="text/javascript">
   <%: Html.FunctionToConcatenateJavaScript() %>
</script>
...

正确的方法是什么？

Answer 1

您可以使用堆栈在 HttpContext 中推送和弹出脚本:

public static class HtmlExtensions
{
    private const string ScriptsKey = "__scripts__";

    public static MvcHtmlString KO_ObjectFor<TModel>(this HtmlHelper<TModel> htmlHelper)
    {
        var stack = htmlHelper.ViewContext.HttpContext.Items[ScriptsKey] as Stack<string>;
        if (stack == null)
        {
            stack = new Stack<string>();
            htmlHelper.ViewContext.HttpContext.Items[ScriptsKey] = stack;
        }
        String str = "some javascript code";
        stack.Push(str);

        return new HtmlString("some code that the helper needs to generate and output to the view");
    }

    public static IHtmlString FunctionToConcatenateJavaScript(this HtmlHelper htmlHelper)
    {
        var stack = htmlHelper.ViewContext.HttpContext.Items[ScriptsKey] as Stack<string>;
        if (stack == null)
        {
            return MvcHtmlString.Empty;
        }

        var scriptTag = new TagBuilder("script");
        scriptTag.Attributes["type"] = "text/javascript";
        var sb = new StringBuilder();
        foreach (var script in stack)
        {
            sb.AppendLine(script);
        }
        scriptTag.InnerHtml = sb.ToString();

        return new HtmlString(scriptTag.ToString());
    }
}

然后你可以推送:

<%= Html.KO_ObjectFor(x => x.Foo) %>
<%= Html.KO_ObjectFor(x => x.Bar) %>
...

然后将它们全部弹出到母版中:

<%= Html.FunctionToConcatenateJavaScript() %>