asp.net-mvc-4 - 如何使用 mvcsitemapprovider 呈现特定的站点地图部分

Question

假设我有站点地图

<mvcSiteMapNode title="Home" controller="Home" action="Index" changeFrequency="Always" >
        <mvcSiteMapNode title="Home" controller="Home" action="Index" visibility="MenuHelper,!*">
            <mvcSiteMapNode title="T1" controller="Home" action="T1" />
            <mvcSiteMapNode title="T2" controller="Home" action="T2"/>
        </mvcSiteMapNode>
        <mvcSiteMapNode title="Help" controller="Help" action="Index">
            <mvcSiteMapNode title="T1" controller="Help" action="T1" />
            <mvcSiteMapNode title="T2" controller="Help" action="T2" />
            <mvcSiteMapNode title="T3" controller="Help" action="T3" />
            <mvcSiteMapNode title="T4" controller="Help" action="T4" />
            <mvcSiteMapNode title="T5" controller="Help" action="T5" />
            <mvcSiteMapNode title="T6" controller="Help" action="T6" />
        </mvcSiteMapNode>
</mvcSiteMapNode>

@Html.MvcSiteMap().Menu() 将显示上面包含节点的菜单但是假设在页脚上我只想显示站点地图中的特定节点，假设我想显示节点 Help:

    <ul>
    <li>
    <a href="/help">
    </li>
    <li>
    <a href="/help/t1">T1</a>
    </li>
    <li>
    <a href="/help/t2">T2</a>
    </li>
    //and so on....
    </ul>

我该怎么做？

我猜我可能需要创建一个自定义模板，但我怎样才能将字符串值传递给自定义模板？

Answer 1

选项 1

一种方法是明确设置起始节点。首先，给起始节点一个明确的键:

<mvcSiteMapNode title="Help" controller="Help" action="Index" key="HelpKey">
    <mvcSiteMapNode title="T1" controller="Help" action="T1" />
    <mvcSiteMapNode title="T2" controller="Help" action="T2" />
    <mvcSiteMapNode title="T3" controller="Help" action="T3" />
    <mvcSiteMapNode title="T4" controller="Help" action="T4" />
    <mvcSiteMapNode title="T5" controller="Help" action="T5" />
    <mvcSiteMapNode title="T6" controller="Help" action="T6" />
</mvcSiteMapNode>

并使用菜单重载:

@Html.MvcSiteMap().Menu(Html.MvcSiteMap().SiteMap.FindSiteMapNodeFromKey("HelpKey"), false, false)

但这样做并不能给你太多的控制权。

选项 2

您还可以使用自定义可见性提供程序。您可以使用 sourceMetaData 字典将自定义数据传递给可见性提供程序，这样您就可以为每个菜单实例创建一个单独的“名称”:

@Html.MvcSiteMap().Menu(new { name = "MainMenu" })
@Html.MvcSiteMap().Menu(new { name = "HelpMenu" })

然后您的自定义可见性提供程序可以使用 FilteredSiteMapNodeVisibilityProvider 用于您的自定义“名称”属性的相同逻辑:

/// <summary>
/// Filtered SiteMapNode Visibility Provider for use with named controls.
/// 
/// Rules are parsed left-to-right, first match wins. Asterisk can be used to match any control or any control name. Exclamation mark can be used to negate a match.
/// </summary>
public class CustomFilteredSiteMapNodeVisibilityProvider
    : SiteMapNodeVisibilityProviderBase
{
    #region ISiteMapNodeVisibilityProvider Members

    /// <summary>
    /// Determines whether the node is visible.
    /// </summary>
    /// <param name="node">The node.</param>
    /// <param name="sourceMetadata">The source metadata.</param>
    /// <returns>
    ///     <c>true</c> if the specified node is visible; otherwise, <c>false</c>.
    /// </returns>
    public override bool IsVisible(ISiteMapNode node, IDictionary<string, object> sourceMetadata)
    {
        // Is a visibility attribute specified?
        string visibility = string.Empty;
        if (node.Attributes.ContainsKey("visibility"))
        {
            visibility = node.Attributes["visibility"].GetType().Equals(typeof(string)) ? node.Attributes["visibility"].ToString() : string.Empty;
        }
        if (string.IsNullOrEmpty(visibility))
        {
            return true;
        }
        visibility = visibility.Trim();

        // Check for the source HtmlHelper
        if (sourceMetadata["HtmlHelper"] == null)
        {
            return true;
        }
        string htmlHelper = sourceMetadata["HtmlHelper"].ToString();
        htmlHelper = htmlHelper.Substring(htmlHelper.LastIndexOf(".") + 1);

        string name = sourceMetadata["name"].ToString();

        // All set. Now parse the visibility variable.
        foreach (string visibilityKeyword in visibility.Split(new[] { ',', ';' }))
        {
            if (visibilityKeyword == htmlHelper || visibilityKeyword == name || visibilityKeyword == "*")
            {
                return true;
            }
            else if (visibilityKeyword == "!" + htmlHelper || visibilityKeyword == "!" + name || visibilityKeyword == "!*")
            {
                return false;
            }
        }

        // Still nothing? Then it's OK!
        return true;
    }

    #endregion
}

然后更新您的配置以使用名称而不是控件类型。

<mvcSiteMapNode title="Home" controller="Home" action="Index" changeFrequency="Always" >
        <mvcSiteMapNode title="Home" controller="Home" action="Index" visibility="MainMenu,!*">
            <mvcSiteMapNode title="T1" controller="Home" action="T1" />
            <mvcSiteMapNode title="T2" controller="Home" action="T2"/>
        </mvcSiteMapNode>
        <mvcSiteMapNode title="Help" controller="Help" action="Index" visibility="HelpMenu,!*">
            <mvcSiteMapNode title="T1" controller="Help" action="T1" />
            <mvcSiteMapNode title="T2" controller="Help" action="T2" />
            <mvcSiteMapNode title="T3" controller="Help" action="T3" />
            <mvcSiteMapNode title="T4" controller="Help" action="T4" />
            <mvcSiteMapNode title="T5" controller="Help" action="T5" />
            <mvcSiteMapNode title="T6" controller="Help" action="T6" />
        </mvcSiteMapNode>
</mvcSiteMapNode>

并且不要忘记将自定义可见性提供程序设置为配置中的默认提供程序。

使用内部 DI (web.config):

<appSettings>
    <add key="MvcSiteMapProvider_DefaultSiteMapNodeVisibiltyProvider" value="MyNamespace.CustomFilteredSiteMapNodeVisibilityProvider, MyAssemblyName"/>
</appSettings>

使用外部 DI(在 DI 模块中 - Ninject 示例所示):

this.Kernel.Bind<ISiteMapNodeVisibilityProviderStrategy>().To<SiteMapNodeVisibilityProviderStrategy>()
    .WithConstructorArgument("defaultProviderName", "MyNamespace.CustomFilteredSiteMapNodeVisibilityProvider, MyAssemblyName");

注意:如果您需要关闭父节点的可见性但保持子节点可见，您应该使用 Menu()、SiteMap() 或 SiteMapPath() 的重载之一允许您将 visibilityAffectsDescendants 参数设置为 false。默认情况下为真。