在web api上接收时属性为null

Question

我的web api中有以下方法

public class AccessPanelController : ApiController
    {
        public HttpResponseMessage PostGrantAccess([FromUri]GrantAccessRequest grantAccessRequest)
        {
            var deviceId = grantAccessRequest.DeviceId;

            var grantAccessResponse = new GrantAccessResponse()
                {
                    Status = "OK"
                };
            var response = Request.CreateResponse<GrantAccessResponse>(HttpStatusCode.OK, grantAccessResponse);
            return response;
        }

    }

GrantAccessRequest类:

public class GrantAccessRequest
{
    public string DeviceId { get; set; }
}

客户:

  HttpClient client = new HttpClient();
            client.BaseAddress = new Uri("http://localhost:55208/");

            // Add an Accept header for JSON format.
            client.DefaultRequestHeaders.Accept.Add(
                new MediaTypeWithQualityHeaderValue("application/json"));

            Uri uri = null;

            var request = new GrantAccessRequest { DeviceId = "bla" };
            var response = client.PostAsJsonAsync("api/accesspanel", uri).Result;
            if (response.IsSuccessStatusCode)
            {
                uri = response.Headers.Location;
            }

在我的PostGrantAccess方法中,grantAccessRequest构造,但是DeviceId为null

Answer 1

摆脱[FromUri]控制器操作的属性.同样在客户端上,您似乎没有对request包含有效负载的变量执行任何操作:

public HttpResponseMessage PostGrantAccess(GrantAccessRequest grantAccessRequest)

为了更好地理解模型绑定在Web API中的工作原理,我建议您阅读following article.

所以:

using (var client = new HttpClient())
{
    client.BaseAddress = new Uri("http://localhost:55208/");

    var request = new GrantAccessRequest { DeviceId = "bla" };
    var response = client.PostAsJsonAsync("api/accesspanel", request).Result;
    if (response.IsSuccessStatusCode)
    {
        var uri = response.Headers.Location;
    }
}

请注意,Accept在这种情况下您不需要设置请求标头,因为您正在使用该PostAsJsonAsync方法.

此外,我不知道你的问题是否这是一个拼写错误,但你似乎已经指定api/accesspanel为url而你的控制器动作被调用GrantAccessRequest.