Question

这是我的路线：

routes.MapRoute(null, "myaccount/monitor/{category}", // Matches
                new { controller = "MyAccount", action = "Monitor", category = (string)null }
);

我想添加一个约束，以便类别只能匹配null或三个参数之一（即概述，投影，历史）

Answer 1

您可以使用UrlParameter.Optional来允许空值，还可以使用MapRoute method的constraints参数..

 routes.MapRoute(null,
                      "myaccount/monitor/{category}", // Matches
                      new { controller = "MyAccount", action = "Monitor", category = UrlParameter.Optional  },
                      new { category = "overview|projection|history"}
            );

Answer 2

内联的Regex Gaby会发布。另一种方法是定义自定义IRouteConstraint：

public class FromValuesListConstraint : IRouteConstraint
{
    private List<string> _values;

    public FromValuesListConstraint(params string[] values)
    {
        this._values = values.Select(x => x.ToLower()).ToList();
    }

    public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
    {
        string value = values[parameterName].ToString();

        if (string.IsNullOrWhiteSpace(value))
        {
            return _values.Contains(string.Empty);
        }

        return _values.Contains(value.ToLower());
    }
}

然后将约束实例传入MapRoute调用：

routes.MapRoute(null,
    "myaccount/monitor/{category}", // Matches
new { controller = "MyAccount", action = "Monitor", category = UrlParameter.Optional  },
new { category = new FromValuesListConstraint ("overview", "projection", "history", string.Empty) }
        );

Answer 3

我认为您可能需要使用不同的路线：

routes.MapRoute("Monitor",
                      "myaccount/monitor", // Matches
                      new { controller = "MyAccount", action = "Monitor" }
            );

routes.MapRoute("MonitorHistory",
                      "myaccount/monitor/history", // Matches
                      new { controller = "MyAccount", action = "Monitor", category = "history" }
            );

routes.MapRoute("MonitorOverview",
                      "myaccount/monitor/overview", // Matches
                      new { controller = "MyAccount", action = "Monitor", category = "overview" }
            );

routes.MapRoute("MonitorProjection",
                      "myaccount/monitor/projection", // Matches
                      new { controller = "MyAccount", action = "Monitor", category = "projection" }
            );

或者，您可能需要执行以下操作：

routes.MapRoute("MonitorGlobal",
                      "myaccount/monitor/{category}", // Matches
                      new { controller = "MyAccount", action = "Monitor", category = string.Empty }
            );

然后在你的控制器中：

public ActionResult Monitor(string category)
{
    switch (category)
    {
        case string.Empty:
            // do something
            break;

        case "overview":
            // do something
            break;

        // so on and so forth

        default:
            // no match, handle accordingly
            break;
    }
}

使用mvc路由约束，因此url只能映射到三个可能的参数之一

3 个答案: