一种解决方案是实现 Html 帮助程序扩展函数，该函数仅加载脚本一次。见下文。 （这也适用于 CSS 和其他包含的文件）。
实现 HtmlHelper 类的扩展和私有支持类作为每个 HttpContext 的单例。
public static class YourHtmlHelperExtensionClass
{
private class TagSrcAttrTracker
{
private TagSrcAttrTracker() { }
public Dictionary<string, string> sources { get; } = new Dictionary<string, string>();
public static TagSrcAttrTrackerInstance {
get {
IDictionary items = HttpContext.Current.Items;
const string instanceName = "YourClassInstanceNameMakeSureItIsUniqueInThisDictionary";
if(!items.Contains(instanceName))
items[instanceName] = new TagSrcAttrTracker();
return items[instanceName] as TagSrcAttrTracker;
}
}
}
public static MvcHtmlString IncludeScriptOnlyOnce(this HtmlHelper helper, string urlOfScript)
{
if(TagSrcAttrTracker.Instance.sources.ContainsKey(urlOfScript))
return null;
TagSrcAttrTracker.Instance.sources[urlOfScript] = urlOfScript;
TagBuilder script = new TagBuilder("script");
scriptTag.MergeAttribute("src", urlOfScript);
return MvcHtmlString.Create(script.ToString());
}
}
然后，将 JavaScript 和其他代码分离到单独的文件中。
示例 .js 文件内容
class MyClass{
myFunction() {
constructor(divId){
this._divId = divId
}
doSomething() {
// do something with a div with id == divId
}
}
}
部分视图的示例 .cshtml 文件内容
<link rel="stylesheet" type="text/css" href="~/Content/CustomCSS/MyPartialView.css"/>
<div id="@ViewBag.id">
Some content! Yay!
</div>
@Html.IncludeScriptOnlyOnce("/Scripts/CustomScripts/MyPartialView.js")
使用部分视图的示例 .cshtml 文件
...
<body>
<h1>Here is some content!</h1>
@Html.Partial("/Views/MyPartial.cshtml", new ViewDataDictionary() { { "id", "id_1"} })
@Html.Partial("/Views/MyPartial.cshtml", new ViewDataDictionary() { { "id", "id_2"} })
@Html.Partial("/Views/MyPartial.cshtml", new ViewDataDictionary() { { "id", "id_3"} })
</body>
<script>
$().ready(
const id1Functionality = new MyClass("id_1") // forgive the poor naming :-)
const id2Functionality = new MyClass("id_3")
const id3Functionality = new MyClass("id_2")
id1Functionality.doSomething();
id2Functionality.doSomething();
id3Functionality.doSomething();
)
</script>
分部视图可能已被包含多次，并且 JavaScript 与分部视图一起打包，但 .js 文件仅在页面中包含一次，因此浏览器不会抱怨 MyClass 被声明多次。
