Web Api 模型验证

1.模型建立，在模型上类上添加System.ComponentModel.DataAnnotations验证属性

public class Product

{

        public int Id { get; set; }

        [Required]

        public string Name { get; set; }

        public decimal Price { get; set; }

        [Range(0, 999)]

        public double Weight { get; set; }

}

2.在ApiController类中使用验证结果

 public HttpResponseMessage Post(Product product)

        {

            if (ModelState.IsValid)

            {

                // Do something with the product (not shown).

                return new HttpResponseMessage(HttpStatusCode.OK);

            }

            else

            {

                return Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);

            }

        }

3.客户端调用并处理验证出错信息

 static async Task RunAsync()

        {

            using (var client = new HttpClient())

            {

                client.BaseAddress = new Uri("http://localhost:57332/");

                client.DefaultRequestHeaders.Accept.Clear();

                client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

                // HTTP POST

                var gizmo = new Product() { Name = "Gizmo", Price = 100, Weight = -200 };

                HttpResponseMessage response = await client.PostAsJsonAsync("api/Product", gizmo);

                if (response.IsSuccessStatusCode)

                {

                    // Get the URI of the created resource.

                    Uri gizmoUrl = response.Headers.Location;

                    Console.WriteLine("Post OK!");

                }

                else if (response.StatusCode == HttpStatusCode.BadRequest)

                {

                    var x = await response.Content.ReadAsStringAsync();

                    Console.WriteLine(x); //输出出错信息

                }

            }

        }

4.利用Filter Attribute来统一处理验证出错信息

建立Filter类

 public class ValidateModelAttribute : ActionFilterAttribute

    {

        public override void OnActionExecuting(HttpActionContext actionContext)

        {

            if (actionContext.ModelState.IsValid == false)

            {

                actionContext.Response = actionContext.Request.CreateErrorResponse(

                    HttpStatusCode.BadRequest, actionContext.ModelState);

            }

        }

在WebApiConfig.cs中添加如下代码

public static void Register(HttpConfiguration config)

{

      config.Filters.Add(new ValidateModelAttribute()); //将这行代码添加进去

 }

这样action中就可以直接写验证通过后的业务逻辑了，在每个action不需要单独使用 if (ModelState.IsValid)方法来判断了，代码变得简洁明了

 [ValidateModel]

    public HttpResponseMessage Post(Product product)

    {

         // Do something with the product (not shown).

                return new HttpResponseMessage(HttpStatusCode.OK);

    }

5.验证效果

响应信息

{StatusCode: 400, ReasonPhrase: 'Bad Request', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:

{

  Pragma: no-cache

  X-SourceFiles: =?UTF-8?B?ZDpcbXkgZG9jdW1lbnRzXHZpc3VhbCBzdHVkaW8gMjAxM1xQcm9qZWN0c1xNb2RlbFZhbGlkYXRpb25EZW1vXE1vZGVsVmFsaWRhdGlvbkRlbW9cYXBpXFByb2R1Y3Q=?=

  Cache-Control: no-cache

  Date: Thu, 07 Apr 2016 14:12:21 GMT

  Server: Microsoft-IIS/8.0

  X-AspNet-Version: 4.0.30319

  X-Powered-By: ASP.NET

  Content-Length: 109

  Content-Type: application/json; charset=utf-8

  Expires: -1

}}

返回XML类型出错信息

返回json格式数据

{"Message":"请求无效。","ModelState":{"product.Weight":["字段 Weight 必须在 0 和 999 之间。"]}}

巴特西