使用Razor View Engine從局部視圖ASP.NET MVC 3將內容注入特定部分

我在_Layout.cshtml定義了此部分

@RenderSection("Scripts", false)

我能夠很容易地從視圖中使用它：

@section Scripts { 
    @*Stuff comes here*@
}

我正在努力的是如何從局部視圖中將一些內容注入到本節中。

假設這是個人視圖頁面：

@section Scripts { 

    <script>
        //code comes here
    </script>
}

<div>
    poo bar poo
</div>

<div>
  @Html.Partial("_myPartial")
</div>

我須要從_myPartial局部視圖的「 Scripts部分中注入一些內容。

我怎樣才能作到這一點？

---

#1樓

這是一個很受歡迎的問題，因此我將發佈解決方案。
我遇到了一樣的問題，儘管它不是理想的，但我認爲它實際上工做得很好，而且不會部分依賴視圖。
個人狀況是，動做自己能夠訪問，但也能夠嵌入到視圖中-谷歌地圖。

在個人_layout我有：

@RenderSection("body_scripts", false)

在個人index視圖中，我有：

@Html.Partial("Clients")
@section body_scripts
{
    @Html.Partial("Clients_Scripts")
}

在個人clients視圖中，我擁有（全部地圖和assoc。html）：

@section body_scripts
{
    @Html.Partial("Clients_Scripts")
}

個人Clients_Scripts視圖包含要呈現到頁面上的javascript

這樣，個人腳本就被隔離了，而且能夠在須要時呈現到頁面中，而body_scripts標籤僅在剃刀視圖引擎找到它的第一次出現時才呈現。

這使我能夠將全部東西分開-這對我來講是一種很好的解決方案，其餘人可能對此有疑問，可是確實解決了「設計使然」的漏洞。

---

#2樓

咱們對Web的思考方式存在一個根本缺陷，尤爲是在使用MVC時。 缺陷在於，JavaScript是視圖的責任。 視圖是視圖，JavaScript（行爲或其餘）是JavaScript。 在Silverlight和WPF的MVVM模式中，咱們面臨的是「視圖優先」或「模型優先」。 在MVC中，咱們應始終嘗試從模型的角度進行推理，而JavaScript在許多方面都是該模型的一部分。

我建議使用AMD模式（我本身喜歡RequireJS ）。 將JavaScript分紅模塊，定義功能並從JavaScript插入html，而不是依賴於視圖來加載JavaScript。 這將清理您的代碼，分散您的顧慮，並使生活變得一路順風。

---

#3樓

從該線程的解決方案中，我提出瞭如下可能過於複雜的解決方案，該解決方案使您能夠延遲在using塊中呈現任何html（腳本）。

用法

建立「部分」

1. 典型場景：在部分視圖中，不管頁面中重複執行該部分視圖多少次，都只包含一次塊：

   @using (Html.Delayed(isOnlyOne: "some unique name for this section")) { <script> someInlineScript(); </script> }

2. 在局部視圖中，每次使用局部時都要包含塊：

   @using (Html.Delayed()) { <b>show me multiple times, @Model.Whatever</b> }

3. 在局部視圖中，不管局部重複了多少次，都只包含一次該塊，但稍後會經過名稱when-i-call-you專門呈現它：

   @using (Html.Delayed("when-i-call-you", isOnlyOne: "different unique name")) { <b>show me once by name</b> <span>@Model.First().Value</span> }

渲染「節」

（即在父視圖中顯示延遲的部分）

@Html.RenderDelayed(); // writes unnamed sections (#1 and #2, excluding #3)
@Html.RenderDelayed("when-i-call-you", false); // writes the specified block, and ignore the `isOnlyOne` setting so we can dump it again
@Html.RenderDelayed("when-i-call-you"); // render the specified block by name
@Html.RenderDelayed("when-i-call-you"); // since it was "popped" in the last call, won't render anything due to `isOnlyOne` provided in `Html.Delayed`

碼

public static class HtmlRenderExtensions {

    /// <summary>
    /// Delegate script/resource/etc injection until the end of the page
    /// <para>@via https://stackoverflow.com/a/14127332/1037948 and http://jadnb.wordpress.com/2011/02/16/rendering-scripts-from-partial-views-at-the-end-in-mvc/ </para>
    /// </summary>
    private class DelayedInjectionBlock : IDisposable {
        /// <summary>
        /// Unique internal storage key
        /// </summary>
        private const string CACHE_KEY = "DCCF8C78-2E36-4567-B0CF-FE052ACCE309"; // "DelayedInjectionBlocks";

        /// <summary>
        /// Internal storage identifier for remembering unique/isOnlyOne items
        /// </summary>
        private const string UNIQUE_IDENTIFIER_KEY = CACHE_KEY;

        /// <summary>
        /// What to use as internal storage identifier if no identifier provided (since we can't use null as key)
        /// </summary>
        private const string EMPTY_IDENTIFIER = "";

        /// <summary>
        /// Retrieve a context-aware list of cached output delegates from the given helper; uses the helper's context rather than singleton HttpContext.Current.Items
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="identifier">optional unique sub-identifier for a given injection block</param>
        /// <returns>list of delayed-execution callbacks to render internal content</returns>
        public static Queue<string> GetQueue(HtmlHelper helper, string identifier = null) {
            return _GetOrSet(helper, new Queue<string>(), identifier ?? EMPTY_IDENTIFIER);
        }

        /// <summary>
        /// Retrieve a context-aware list of cached output delegates from the given helper; uses the helper's context rather than singleton HttpContext.Current.Items
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="defaultValue">the default value to return if the cached item isn't found or isn't the expected type; can also be used to set with an arbitrary value</param>
        /// <param name="identifier">optional unique sub-identifier for a given injection block</param>
        /// <returns>list of delayed-execution callbacks to render internal content</returns>
        private static T _GetOrSet<T>(HtmlHelper helper, T defaultValue, string identifier = EMPTY_IDENTIFIER) where T : class {
            var storage = GetStorage(helper);

            // return the stored item, or set it if it does not exist
            return (T) (storage.ContainsKey(identifier) ? storage[identifier] : (storage[identifier] = defaultValue));
        }

        /// <summary>
        /// Get the storage, but if it doesn't exist or isn't the expected type, then create a new "bucket"
        /// </summary>
        /// <param name="helper"></param>
        /// <returns></returns>
        public static Dictionary<string, object> GetStorage(HtmlHelper helper) {
            var storage = helper.ViewContext.HttpContext.Items[CACHE_KEY] as Dictionary<string, object>;
            if (storage == null) helper.ViewContext.HttpContext.Items[CACHE_KEY] = (storage = new Dictionary<string, object>());
            return storage;
        }


        private readonly HtmlHelper helper;
        private readonly string identifier;
        private readonly string isOnlyOne;

        /// <summary>
        /// Create a new using block from the given helper (used for trapping appropriate context)
        /// </summary>
        /// <param name="helper">the helper from which we use the context</param>
        /// <param name="identifier">optional unique identifier to specify one or many injection blocks</param>
        /// <param name="isOnlyOne">extra identifier used to ensure that this item is only added once; if provided, content should only appear once in the page (i.e. only the first block called for this identifier is used)</param>
        public DelayedInjectionBlock(HtmlHelper helper, string identifier = null, string isOnlyOne = null) {
            this.helper = helper;

            // start a new writing context
            ((WebViewPage)this.helper.ViewDataContainer).OutputStack.Push(new StringWriter());

            this.identifier = identifier ?? EMPTY_IDENTIFIER;
            this.isOnlyOne = isOnlyOne;
        }

        /// <summary>
        /// Append the internal content to the context's cached list of output delegates
        /// </summary>
        public void Dispose() {
            // render the internal content of the injection block helper
            // make sure to pop from the stack rather than just render from the Writer
            // so it will remove it from regular rendering
            var content = ((WebViewPage)this.helper.ViewDataContainer).OutputStack;
            var renderedContent = content.Count == 0 ? string.Empty : content.Pop().ToString();
            // if we only want one, remove the existing
            var queue = GetQueue(this.helper, this.identifier);

            // get the index of the existing item from the alternate storage
            var existingIdentifiers = _GetOrSet(this.helper, new Dictionary<string, int>(), UNIQUE_IDENTIFIER_KEY);

            // only save the result if this isn't meant to be unique, or
            // if it's supposed to be unique and we haven't encountered this identifier before
            if( null == this.isOnlyOne || !existingIdentifiers.ContainsKey(this.isOnlyOne) ) {
                // remove the new writing context we created for this block
                // and save the output to the queue for later
                queue.Enqueue(renderedContent);

                // only remember this if supposed to
                if(null != this.isOnlyOne) existingIdentifiers[this.isOnlyOne] = queue.Count; // save the index, so we could remove it directly (if we want to use the last instance of the block rather than the first)
            }
        }
    }


    /// <summary>
    /// <para>Start a delayed-execution block of output -- this will be rendered/printed on the next call to <see cref="RenderDelayed"/>.</para>
    /// <para>
    /// <example>
    /// Print once in "default block" (usually rendered at end via <code>@Html.RenderDelayed()</code>).  Code:
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>show at later</b>
    ///     <span>@Model.Name</span>
    ///     etc
    /// }
    /// </code>
    /// </example>
    /// </para>
    /// <para>
    /// <example>
    /// Print once (i.e. if within a looped partial), using identified block via <code>@Html.RenderDelayed("one-time")</code>.  Code:
    /// <code>
    /// @using (Html.Delayed("one-time", isOnlyOne: "one-time")) {
    ///     <b>show me once</b>
    ///     <span>@Model.First().Value</span>
    /// }
    /// </code>
    /// </example>
    /// </para>
    /// </summary>
    /// <param name="helper">the helper from which we use the context</param>
    /// <param name="injectionBlockId">optional unique identifier to specify one or many injection blocks</param>
    /// <param name="isOnlyOne">extra identifier used to ensure that this item is only added once; if provided, content should only appear once in the page (i.e. only the first block called for this identifier is used)</param>
    /// <returns>using block to wrap delayed output</returns>
    public static IDisposable Delayed(this HtmlHelper helper, string injectionBlockId = null, string isOnlyOne = null) {
        return new DelayedInjectionBlock(helper, injectionBlockId, isOnlyOne);
    }

    /// <summary>
    /// Render all queued output blocks injected via <see cref="Delayed"/>.
    /// <para>
    /// <example>
    /// Print all delayed blocks using default identifier (i.e. not provided)
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>show me later</b>
    ///     <span>@Model.Name</span>
    ///     etc
    /// }
    /// </code>
    /// -- then later --
    /// <code>
    /// @using (Html.Delayed()) {
    ///     <b>more for later</b>
    ///     etc
    /// }
    /// </code>
    /// -- then later --
    /// <code>
    /// @Html.RenderDelayed() // will print both delayed blocks
    /// </code>
    /// </example>
    /// </para>
    /// <para>
    /// <example>
    /// Allow multiple repetitions of rendered blocks, using same <code>@Html.Delayed()...</code> as before.  Code:
    /// <code>
    /// @Html.RenderDelayed(removeAfterRendering: false); /* will print */
    /// @Html.RenderDelayed() /* will print again because not removed before */
    /// </code>
    /// </example>
    /// </para>

    /// </summary>
    /// <param name="helper">the helper from which we use the context</param>
    /// <param name="injectionBlockId">optional unique identifier to specify one or many injection blocks</param>
    /// <param name="removeAfterRendering">only render this once</param>
    /// <returns>rendered output content</returns>
    public static MvcHtmlString RenderDelayed(this HtmlHelper helper, string injectionBlockId = null, bool removeAfterRendering = true) {
        var stack = DelayedInjectionBlock.GetQueue(helper, injectionBlockId);

        if( removeAfterRendering ) {
            var sb = new StringBuilder(
#if DEBUG
                string.Format("<!-- delayed-block: {0} -->", injectionBlockId)
#endif
                );
            // .count faster than .any
            while (stack.Count > 0) {
                sb.AppendLine(stack.Dequeue());
            }
            return MvcHtmlString.Create(sb.ToString());
        } 

        return MvcHtmlString.Create(
#if DEBUG
                string.Format("<!-- delayed-block: {0} -->", injectionBlockId) + 
#endif
            string.Join(Environment.NewLine, stack));
    }


}

---

#4樓

若是確實有須要從partial運行一些js ，請按如下步驟操做，須要使用jQuery ：

<script type="text/javascript">        
    function scriptToExecute()
    {
        //The script you want to execute when page is ready.           
    }

    function runWhenReady()
    {
        if (window.$)
            scriptToExecute();                                   
        else
            setTimeout(runWhenReady, 100);
    }
    runWhenReady();
</script>

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#5樓

您無需在局部視圖中使用部分。

包括在您的局部視圖中。 jQuery加載後執行該函數。 您能夠更改代碼的條件子句。

<script type="text/javascript">    
var time = setInterval(function () {
    if (window.jQuery != undefined) {
        window.clearInterval(time);

        //Begin
        $(document).ready(function () {
           //....
        });
        //End
    };
}, 10); </script>

朱利奧·斯派德