VaryByCustom和模型绑定

Question

我有一个类我模型绑定,我想使用它的输出缓存.我找不到一种方法来访问绑定对象GetVaryByCustomString

例如:

public class MyClass
{
    public string Id { get; set; }
    ... More properties here
}

public class MyClassModelBinder : DefaultModelBinder
{
   public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
   {
      var model = new MyClass();
      ... build the class       
      return model;
    }
}

我在Global.cs中设置了绑定器

ModelBinders.Binders.Add(typeof(MyClass), new MyClassModelBinder());

然后像这样使用输出缓存.

[OutputCache(Duration = 300, VaryByCustom = "myClass")]
public ActionResult MyAction(MyClass myClass)
{
   .......

public override string GetVaryByCustomString(HttpContext context, string custom)
{
   ... check we're working with 'MyClass'

   var routeData = RouteTable.Routes.GetRouteData(new HttpContextWrapper(context));
   var myClass = (MyClass)routeData.Values["myClass"]; <-- This is always null

虽然模型绑定器已触发,但myClass不在路由表事件中.

一如既往的帮助将是最受欢迎的.

干杯

Answer 1

模型绑定器不会将模型添加到RouteData,因此您不能期望从那里获取它.

一种可能性是将模型存储在HttpContext自定义模型绑定器内部:

public class MyClassModelBinder : DefaultModelBinder
{
   public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
   {
      var model = new MyClass();
      // ... build the class

      // Store the model inside the HttpContext so that it is accessible later
      controllerContext.HttpContext.Items["model"] = model;
      return model;
    }
}

然后GetVaryByCustomString使用相同的密钥model在我的方法中检索它(在我的例子中):

public override string GetVaryByCustomString(HttpContext context, string custom)
{
    var myClass = (MyClass)context.Items["model"];

    ...
}