c# - 如何在PartialViews内串联由HtmlHelper扩展生成的JavaScript并将其添加到父 View ？

我在父视图中有2个PartialViews。

在这两个PartiaViews中，我生成了一些JavaScript代码，这些代码需要包含在父视图的底部。

这是HtmlHelper扩展，可在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);
}

这是父视图（主视图）

...
//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>
...

什么是正确的方法？

最佳答案

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());
    }
}

那么您可以推送：

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

然后在主目录中全部弹出它们：

<%= Html.FunctionToConcatenateJavaScript() %>