Asp.Net MVC：如何確定您目前是否處於特定視圖

Question

我需要確定我是否處於特定視圖。我的用例是，我想用當前視圖的「on」類裝飾導航元素。有沒有內置的方法來做到這一點？

Answer 1

在這裏，我正在使用。我認爲這實際上是由VS中的MVC項目模板生成的：

public static bool IsCurrentAction(this HtmlHelper helper, string actionName, string controllerName) 
    { 
     string currentControllerName = (string)helper.ViewContext.RouteData.Values["controller"]; 
     string currentActionName = (string)helper.ViewContext.RouteData.Values["action"]; 

     if (currentControllerName.Equals(controllerName, StringComparison.CurrentCultureIgnoreCase) && currentActionName.Equals(actionName, StringComparison.CurrentCultureIgnoreCase)) 
      return true; 

     return false; 
    } 

Answer 2

我目前的解決方案是擴展方法：

public static class UrlHelperExtensions 
{ 
    /// <summary> 
    /// Determines if the current view equals the specified action 
    /// </summary> 
    /// <typeparam name="TController">The type of the controller.</typeparam> 
    /// <param name="helper">Url Helper</param> 
    /// <param name="action">The action to check.</param> 
    /// <returns> 
    ///  <c>true</c> if the specified action is the current view; otherwise, <c>false</c>. 
    /// </returns> 
    public static bool IsAction<TController>(this UrlHelper helper, LambdaExpression action) where TController : Controller 
    { 
     MethodCallExpression call = action.Body as MethodCallExpression; 
     if (call == null) 
     { 
      throw new ArgumentException("Expression must be a method call", "action"); 
     } 

     return (call.Method.Name.Equals(helper.ViewContext.ViewName, StringComparison.OrdinalIgnoreCase) && 
       typeof(TController) == helper.ViewContext.Controller.GetType()); 
    } 

    /// <summary> 
    /// Determines if the current view equals the specified action 
    /// </summary> 
    /// <param name="helper">Url Helper</param> 
    /// <param name="actionName">Name of the action.</param> 
    /// <returns> 
    ///  <c>true</c> if the specified action is the current view; otherwise, <c>false</c>. 
    /// </returns> 
    public static bool IsAction(this UrlHelper helper, string actionName) 
    { 
     if (String.IsNullOrEmpty(actionName)) 
     { 
      throw new ArgumentException("Please specify the name of the action", "actionName"); 
     } 
     string controllerName = helper.ViewContext.RouteData.GetRequiredString("controller"); 
     return IsAction(helper, actionName, controllerName); 
    } 

    /// <summary> 
    /// Determines if the current view equals the specified action 
    /// </summary> 
    /// <param name="helper">Url Helper</param> 
    /// <param name="actionName">Name of the action.</param> 
    /// <param name="controllerName">Name of the controller.</param> 
    /// <returns> 
    ///  <c>true</c> if the specified action is the current view; otherwise, <c>false</c>. 
    /// </returns> 
    public static bool IsAction(this UrlHelper helper, string actionName, string controllerName) 
    { 
     if (String.IsNullOrEmpty(actionName)) 
     { 
      throw new ArgumentException("Please specify the name of the action", "actionName"); 
     } 
     if (String.IsNullOrEmpty(controllerName)) 
     { 
      throw new ArgumentException("Please specify the name of the controller", "controllerName"); 
     } 

     if (!controllerName.EndsWith("Controller", StringComparison.OrdinalIgnoreCase)) 
     { 
      controllerName = controllerName + "Controller"; 
     } 

     bool isOnView = helper.ViewContext.ViewName.SafeEquals(actionName, StringComparison.OrdinalIgnoreCase); 
     return isOnView && helper.ViewContext.Controller.GetType().Name.Equals(controllerName, StringComparison.OrdinalIgnoreCase); 
    } 
} 

Answer 3

這裏是東西有點不同，使用FilterAttribute：

[NavigationLocationFilter("Products")] 
    public ViewResult List() 
    { 
     return View(); 
    } 

...

public class NavigationLocationFilterAttribute : ActionFilterAttribute 
{ 
    public string CurrentLocation { get; set; } 

    public NavigationLocationFilterAttribute(string currentLocation) 
    { 
     CurrentLocation = currentLocation; 
    } 

    public override void OnActionExecuting(ActionExecutingContext filterContext) 
    { 
     var controller = (Controller)filterContext.Controller; 
     controller.ViewData.Add("NavigationLocation", CurrentLocation); 
    } 
} 

...

A nd在視圖中：

<%= ViewData["NavigationLocation"] %>