Route.Constraints 屬性

定義

命名空間:

System.Web.Routing

組件:

System.Web.dll

取得或設定運算式的字典，這些運算式指定 URL 參數的有效值。

public:
 property System::Web::Routing::RouteValueDictionary ^ Constraints { System::Web::Routing::RouteValueDictionary ^ get(); void set(System::Web::Routing::RouteValueDictionary ^ value); };

public System.Web.Routing.RouteValueDictionary Constraints { get; set; }

member this.Constraints : System.Web.Routing.RouteValueDictionary with get, set

Public Property Constraints As RouteValueDictionary

屬性值

RouteValueDictionary

物件，包含參數名稱和運算式。

範例

下列範例示範如何建立 Route 物件，並設定 Constraints、 DataTokens和 Defaults 屬性。

void Application_Start(object sender, EventArgs e) 
{
    RegisterRoutes(RouteTable.Routes);
}

public static void RegisterRoutes(RouteCollection routes)
{
    Route reportRoute = new Route("{locale}/{year}", new ReportRouteHandler());
    reportRoute.Defaults = new RouteValueDictionary { { "locale", "en-US" }, { "year", DateTime.Now.Year.ToString() } };
    reportRoute.Constraints = new RouteValueDictionary { { "locale", "[a-z]{2}-[a-z]{2}" }, { "year", @"\d{4}" } };
    reportRoute.DataTokens = new RouteValueDictionary { { "format", "short" } };
    routes.Add(reportRoute);
}

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    RegisterRoutes(RouteTable.Routes)
End Sub

Shared Sub RegisterRoutes(ByVal routes As RouteCollection)
    Dim urlPattern As String
    Dim reportRoute As Route
    
    urlPattern = "{locale}/{year}"
    
    reportRoute = New Route(urlPattern, New ReportRouteHandler)
    reportRoute.Defaults = New RouteValueDictionary(New With {.locale = "en-US", .year = DateTime.Now.Year.ToString()})
    reportRoute.Constraints = New RouteValueDictionary(New With {.locale = "[a-z]{2}-[a-z]{2}", .year = "\d{4}"})
    reportRoute.DataTokens = New RouteValueDictionary(New With {.format = "short"})

    routes.Add(reportRoute)
End Sub

下列範例顯示 Route 物件，其 Constraints 屬性包含名為 的參數 httpMethod ，且具有 值的 類別實例 HttpMethodConstraint 。

void Application_Start(object sender, EventArgs e) 
{
    RegisterRoutes(RouteTable.Routes);
}

public static void RegisterRoutes(RouteCollection routes)
{
    string[] allowedMethods = { "GET", "POST" };
    HttpMethodConstraint methodConstraints = new HttpMethodConstraint(allowedMethods);

    Route reportRoute = new Route("{locale}/{year}", new ReportRouteHandler());
    reportRoute.Constraints = new RouteValueDictionary { { "httpMethod", methodConstraints } };

    routes.Add(reportRoute);
}

Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    RegisterRoutes(RouteTable.Routes)
End Sub

Shared Sub RegisterRoutes(ByVal routes As RouteCollection)
    Dim urlPattern As String
    Dim reportRoute As Route
    Dim allowedMethods() As String = {"GET", "POST"}
    Dim methodConstraints As HttpMethodConstraint  
    
    methodConstraints = New HttpMethodConstraint(allowedMethods)
    
    Dim constraintValues = New With {.httpMethod = methodConstraints}
    
    urlPattern = "{locale}/{year}"
    
    reportRoute = New Route(urlPattern, New ReportRouteHandler)
    reportRoute.Constraints = New RouteValueDictionary(constraintValues)
    
    routes.Add(reportRoute)
End Sub

備註

屬性 Constraints 可讓您限制路由所處理之 URL 參數可接受的值。 您會將 RouteValueDictionary 物件指派給 Constraints 屬性。 物件中的每個 RouteValueDictionary 元素都包含參數的名稱和下列其中一項：

• 定義正則表達式的字串。 正則表達式不區分大小寫。

• 實作 介面且 IRouteConstraint 包含 Match 方法的物件。

HttpMethodConstraint 類別會實作 IRouteConstraint 介面。 您可以將 類別的 HttpMethodConstraint 實例納入為條件約束，以指定路由可接受的 HTTP 動詞。

另請參閱

• ASP.NET 路由