Web API如何獲取列表並為ASP.NET Web API返回不同的類型

Question

我在一個項目中，我想在一個Web API方法中添加list<restaurant > ，並返回restaurant和rest_location之間的不同類型的混合。 restaurant和rest_location之間的關系是一對多的。

當我運行它時，出現錯誤：

{“消息”：“請求的資源不支持http方法'GET'。”}

服務器Web API：

[HttpPost]
[Route("api/Restaurants/res_by_locat/{x}/{res_loc}")]
[ResponseType(typeof(Restaurant))]
[ResponseType(typeof(Rest_Location))]
public HttpResponseMessage GetResturantsBylocation([FromUri]int x,[FromBody] List<Rest_Location> res_loc)
{
    List<Table> table = new List<Table>();
    var lstitem = from t1 in res_loc
                  from t2 in db.Restaurants.Where(y => y.R_ID == t1.R_ID )
                                  .DefaultIfEmpty()
                  select new { t1.L_Adress, t2.R_Name };

    //foreach (var item in lstitem)
    //{
    //    table.Add(item);
    //}
    if (lstitem == null || !lstitem.Any())
    {
        throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
    }

    else return ControllerContext.Request.CreateResponse(HttpStatusCode.OK, new { lstitem });          
}

客戶：

protected void btn_ddl_Click(object sender, EventArgs e)
{
    if (locationddl.SelectedValue == "0")
    {
        lbl_result.Text = "Chose a Location First ! ";               
    }
    else
    {
        try
        {
            HttpClient client = new HttpClient();
            client.BaseAddress = new Uri("http://localhost:10566/");
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Accept.Add(
                new MediaTypeWithQualityHeaderValue("application/json"));
            var fromddl = locationddl.SelectedItem.Text;
            //lbl_result.Text = fromddl;
            var response = client.GetAsync("api/Locations/getid_by_name/" + fromddl).Result;
            // if (Page.IsValid)
            {
                if (response.IsSuccessStatusCode)
                {
                    Location ll = response.Content.ReadAsAsync<Location>().Result;
                    int x = ll.L_ID;

                    lbl_msg.Text = x.ToString();

                    var response2_get_ids_Rests = client.GetAsync("api/Rest_Location/res_by_locat/" + x).Result;

                    if (response2_get_ids_Rests.IsSuccessStatusCode)
                    {
                        List<Rest_Location> rests_locations = response2_get_ids_Rests.Content.ReadAsAsync<List<Rest_Location>>().Result;
                        //var items= rests_locations.FirstOrDefault(rl => rl.L_ID == x);
                       // GridView2.DataSource = rests_locations;
                         //   GridView2.DataBind();
                        HttpResponseMessage response3_get_resturants_by = client.PostAsJsonAsync("api/Restaurants/res_by_locat/" + x , rests_locations).Result;
                        if (response3_get_resturants_by.IsSuccessStatusCode)
                        {
                            var news= response3_get_resturants_by.Content.ReadAsAsync<List<Restaurant>>().Result;
                            GridView1.DataSource = news;
                            GridView1.DataBind();

                            lbl_msg.Text = "Search succesed";
                        }
                        else
                        {
                            lbl_test.Text = " not found ";
                        }
                    }
                    else
                    {
                        lbl_test.Text = " not found ";
                    }
                }
            }
        }
        catch (Exception ex)
        {
            lbl_msg.Text = "Couldn't Found Resaurants ! " + ex.ToString();
        }
    }
}

Answer 1

您的端點具有此屬性[HttpPost] ，這意味着只能使用POST訪問它

您的客戶端正在嘗試使用GET訪問端點。

您應該使用client.PostAsync方法而不是GetAsync 。