如何讓過濾器重定向到另一個動作？

Question

RedirectToAction受保護，我們只能在行動中使用它。但是如果我想在過濾器中重定向？

public class IsGuestAttribute: ActionFilterAttribute 
{ 
    public override void OnActionExecuting(ActionExecutingContext filterContext) 
    { 
     if (!Ctx.User.IsGuest) 
      filterContext.Result = (filterContext.Controller as Controller) 
       .RedirectToAction("Index", "Home"); 
    } 
} 

Answer 1

RedirectToAction只是一種輔助方法來構造一個RedirectToRouteResult()，所以你做的是簡單地創建一個新的RedirectToRouteResult()沿RouteValueDictionary()傳遞與值你的行動。在下面的評論基於從@Domenic代碼

完整的示例：

public class IsGuestAttribute: ActionFilterAttribute 
{ 
    public override void OnActionExecuting(ActionExecutingContext filterContext) 
    { 
     if (!Ctx.User.IsGuest) 
     { 
      filterContext.Result = new RedirectToRouteResult(
       new RouteValueDictionary 
       { 
        { "controller", "Home" }, 
        { "action", "Index" } 
       }); 
     } 
    } 
} 

Answer 2

下面是一個代碼示例：

public override void OnActionExecuting(ActionExecutingContext filterContext) 
{ 

    if (!Ctx.User.IsGuest) 
    { 
     RouteValueDictionary redirectTargetDictionary = new RouteValueDictionary(); 
     redirectTargetDictionary.Add("action", "Index"); 
     redirectTargetDictionary.Add("controller", "Home"); 

     filterContext.Result = new RedirectToRouteResult(redirectTargetDictionary); 
    } 
} 

Answer 3

安全/授權/認證過濾器應使用AuthorizeAttribute和IAuthorizationFilter。

public class IsGuestAttribute: AuthorizeAttribute, IAuthorizationFilter 
{ 
    public void OnResultExecuted(ResultExecutedContext filterContext) 
    { 
    } 
    public void OnActionExecuting(ActionExecutingContext filterContext) 
    { 
     if (!Ctx.User.IsGuest) 
     { 
      filterContext.Result = new RedirectToRouteResult(
       new RouteValueDictionary 
       { 
        { "controller", "Home" }, 
        { "action", "Index" } 
       }); 
     } 
    } 
} 

Answer 4

我知道我有點遲到了，但我用veggerby的解決方案，並建立了一個輔助類，可能是對某些人有用的，所以我想在這裏它提供：

public static class ActionFilterHelpers 
{ 
    public static void Redirect(this ActionExecutingContext filterContext, String controller, String action, object routeValues) 
    { 
     filterContext.Result = Redirect(controller, action, routeValues); 
    } 

    public static ActionResult Redirect(String controller, String action, object routeValues) 
    { 
     var routeValues = new RouteValueDictionary(); 

     routeValues["controller"] = controller; 
     routeValues["action"] = action; 

     foreach (var keyValue in new ObjectDictionary(routeValues)) 
      routeValues.Add(keyValue.Key, keyValue.Value); 

     return new RedirectToRouteResult(routeValues); 
    } 
} 

我提供了一個返回重定向的靜態方法ActionResult和一個擴展方法，它擴展了filterContext。希望有人認爲這有用。

ObjectDictionary是一個使用反射從構造它的對象的屬性創建字典的類。我沒有包含那些代碼，因爲我相信在框架的某個地方有更好的方法來做。我還沒有找到它，但我不希望別人繼承我的潛在錯誤。

Answer 5

用法：filterContext.RedirectToAction("Login", "Account");

這裏是一個輔助類，我寫在更多的地方提供RedirectToAction一些功能擴展方法寫的。對於OP來說這太晚了，但希望它可以幫助別人！

public static class RedirectHelper 
{ 
    // RedirectToAction Extension Methods 
    public static void RedirectToAction(this HttpResponseBase response, String action, String controller, object routeValues = null, bool endResponse = false) 
    { 
     response.RedirectToRoute(CreateRoute(action, controller, routeValues)); 
     if (endResponse) response.End(); 
    } 
    public static void RedirectToAction(this HttpResponse response, String action, String controller, object routeValues = null, bool endResponse = false) 
    { 
     response.RedirectToRoute(CreateRoute(action, controller, routeValues)); 
     if (endResponse) response.End(); 
    } 
    public static void RedirectToAction(this ActionExecutingContext filterContext, String action, String controller, object routeValues = null, bool endResponse = false) 
    { 
     if (endResponse) filterContext.HttpContext.Response.RedirectToAction(action, controller, routeValues, true); 
     else filterContext.Result = new RedirectToRouteResult(CreateRoute(action, controller, routeValues)); 
    } 
    public static void RedirectToAction(this ExceptionContext filterContext, String action, String controller, object routeValues = null, bool endResponse = false) 
    { 
     if (endResponse) filterContext.HttpContext.Response.RedirectToAction(action, controller, routeValues, true); 
     else { 
      filterContext.ExceptionHandled = true; 
      filterContext.Result = new RedirectToRouteResult(CreateRoute(action, controller, routeValues)); 
     } 
    } 
    // Route Value Derivation 
    public static RouteValueDictionary CreateRoute(String action, String controller, object routeValues = null) 
    { 
     RouteValueDictionary result = routeValues != null ? 
      HtmlHelper.AnonymousObjectToHtmlAttributes(routeValues) : 
      new RouteValueDictionary(); 
     result["controller"] = controller; 
     result["action"] = action; 
     return result; 
    } 
} 

還有更多ControllerContexts沒有包括在內，但根據您的需求添加您自己的控件應該很容易。