在ExceptionFilterAttribute-HttpActionExecutedContext中获取控制器的返回类型

Question

If somewhere within the request lifecycle, an exception is thrown, the HttpActionExecutedContext has a null response.

public class MyExceptionFilterAttribute : ExceptionFilterAttribute
{    
    public override void OnException(HttpActionExecutedContext httpActionExecutedContext)
    {
        // Get expected return type here
        // Can't be httpActionExecutedContext.Response.GetType() because response is null
    }
}

What I'm trying to do is return the same expected object, but with an error created in one of the object's fields.

Is there a way to figure out what the expected response type is?

Answer 1

The information you seek is within the provided context. You just have to go a little deeper to find it in the action descriptor.

public class MyExceptionFilterAttribute : ExceptionFilterAttribute  
    public override void OnException(HttpActionExecutedContext httpActionExecutedContext) {
        // Get expected return type here
        var expectedReturnType = httpActionExecutedContext.ActionContext.ActionDescriptor.ReturnType;

    }
}