Web Api - 如何直接从OnActionExecuting过滤器停止Web管道

Question

我有一个pre-action web api钩子,它将检查ModelState.IsValid.如果ModelState无效,我不想执行该操作,只是立即返回我的消息.我到底该怎么做？

public class ValidateModelStateAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext actionContext) {
        if (!actionContext.ModelState.IsValid)
        {
            var msg = actionContext.Request.CreateErrorResponse(HttpStatusCode.BadRequest, actionContext.ModelState);
            // Now What?
        }
        base.OnActionExecuting(actionContext);
    }
}

Answer 1

设置Response.Result.如果结果不为null,则不会执行该操作.确切的语法现在正在逃避我,但它很简单

if(actionContext.ModelState.IsValid == false)
{
       var response = actionContext.Request.CreateErrorResponse(...);
       actionContext.Response = response;
}   

Answer 2

您是否真的在ASP.NET WebApi页面上看到了这个示例？

看起来非常像你想要实现的,他们所做的就是设置Context对象的Response:

If model validation fails, this filter returns an HTTP response that contains the validation errors. In that case, the controller action is not invoked.

http://www.asp.net/web-api/overview/formats-and-model-binding/model-validation-in-aspnet-web-api

看到: Handling Validation Errors