如何将 t4mvc 路由助手与自定义路由约束一起使用

Question

我在当前项目中使用 t4mvc 并尝试使用包含的路由助手，但是当我尝试使用如下所示的自定义约束时，

     routes.MapRoute(
        "def_filtered_reports_route",
        "reports/{samplePoint}/{fromDate}/{toDate}",
        MVC.Report.Results(null, null, null),
        new
        {
            samplePoint = new SamplePointExistsConstraint(),
            fromDate = new DateTimeConstraint(),
            toDate = new DateTimeConstraint()
        }
        );

它会抛出一个 ArgumentException ，说明 具有相同键的项目已经添加。

如果我这样写

 routes.MapRoute(
    "def_filtered_reports_route",
    "reports/{samplePoint}/{fromDate}/{toDate}",
    MVC.Report.Results(null, null, null) );

或这样

    routes.MapRoute(
           "def_filtered_reports_route",
           "reports/{samplePoint}/{fromDate}/{toDate}",
           new
           {
               controller = "Report",
               action = "Results",
               fromDate = "",
               toDate = "",
               samplePoint = ""
           },
           new
           {
               fromDate = new DateTimeConstraint(),
               toDate = new DateTimeConstraint(),
               samplePoint = new SamplePointExistsConstraint()
           });

写它就可以正常工作。

有什么我遗漏的或者 t4mvc 不支持自定义约束吗

Answer 1

尝试在约束之前为默认值传递一个额外的空值。例如

        routes.MapRoute(
           "def_filtered_reports_route",
           "reports/{samplePoint}/{fromDate}/{toDate}",
           MVC.Report.Results(null, null, null),
           null /*defaults*/,
           new {
               samplePoint = new SamplePointExistsConstraint(),
               fromDate = new DateTimeConstraint(),
               toDate = new DateTimeConstraint()
           }
           );