. net Core 5 web应用程序中带有复杂json值的Http GET请求

Question

我正在尝试做一个get请求，这是我的razor页面类:

public class IndexModel : PageModel
{
public IEnumerable<ApiAnime> ApiData { get; set; } 
public async Task<IActionResult> OnGet()
{
var request = new HttpRequestMessage(HttpMethod.Get,
"https://api.aniapi.com/v1/anime");
var client = _clientFactory.CreateClient();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.SendAsync(request);
if (response.IsSuccessStatusCode)
{
var responseStream = await response.Content.ReadAsStreamAsync();
ApiData = await JsonSerializer.DeserializeAsync<IEnumerable<ApiAnime>>(responseStream);
}
else
{
ApiData = new List<ApiAnime>();
}
return Page();
}
}

这个razor page类似乎可以处理更简单或更直接的json值。但是有了这个api "https://api.aniapi.com/v1/anime"这似乎行不通。这是我的json类:

public class ApiAnime
{
public class Rootobject
{
public int status_code { get; set; }
public string message { get; set; }
public Data data { get; set; }
public string version { get; set; }
}
public class Data
{
public int current_page { get; set; }
public int count { get; set; }
public Document[] documents { get; set; }
public int last_page { get; set; }
}
public class Document
{
public int anilist_id { get; set; }
public int mal_id { get; set; }
public int format { get; set; }
public int status { get; set; }
public Titles titles { get; set; }
public Descriptions descriptions { get; set; }
public DateTime start_date { get; set; }
public DateTime end_date { get; set; }
public int season_period { get; set; }
public int season_year { get; set; }
public int episodes_count { get; set; }
public int episode_duration { get; set; }
public string trailer_url { get; set; }
public string cover_image { get; set; }
public string cover_color { get; set; }
public string banner_image { get; set; }
public string[] genres { get; set; }
public int score { get; set; }
public int id { get; set; }
public int prequel { get; set; }
public int sequel { get; set; }
}
}

我得到的错误是

The JSON value could not be converted to System.Collections.Generic.IEnumerable`1[AnimDbNet.ApiModel.ApiAnime].
ApiData = await JsonSerializer.DeserializeAsync<IEnumerable<ApiAnime>>(responseStream);

我正在使用。net Core 5。有人知道如何修复这个错误吗?

Answer 1

该错误是由于试图解析API的返回值，该返回值不是JSON数组，而是JSON对象，而不是IEnumerable。

ApiData = await JsonSerializer.DeserializeAsync<IEnumerable<ApiAnime>>(responseStream);

解决方案是直接解析到ApiAnime.Rootobject，然后使用apiData.Data访问页面上的数据。你的代码应该是这样的:

public class IndexModel : PageModel
{
public ApiAnime.Rootobject ApiData { get; set; } 
public async Task<IActionResult> OnGet()
{
var request = new HttpRequestMessage(HttpMethod.Get,
"https://api.aniapi.com/v1/anime");
var client = _clientFactory.CreateClient();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.SendAsync(request);
if (response.IsSuccessStatusCode)
{
var responseStream = await response.Content.ReadAsStreamAsync();
ApiData = await JsonSerializer.DeserializeAsync<ApiAnime.Rootobject>(responseStream);
}
else
{
ApiData = new ApiAnime.Rootobject();
}
return Page();
}
}

Answer 2

你不应该需要IEnumerable，它应该通过使用Rootobject来工作。

JsonSerializer.DeserializeAsync<Rootobject>(responseStream);

这个API发送的json以:

开头

{
"status_code": 200,
"message": "Page 1 contains 100 anime. Last page number is 153 for a total of 15280 anime",
"data": {
...

这是根对象的开始。

Answer 3

你不需要IEnumerable。试试这段代码。它已经在Visual Studio中测试过了，可以正常工作。

public class IndexModel : PageModel
{
public ApiData ApiData { get; set; } 

public async Task<IActionResult> OnGet()
{
var apiDataRoot= await GetApiData(_httpClientFactory);
if (apidatRoot.status_code=200)  ApiData=apiDataRoot.ApiData;
else ... return error;

return Page();
}
}

GetApiData

public async Task<ApiDataRoot> GetApiData(IHttpClientFactory httpClientFactory)
{
var request = new HttpRequestMessage(HttpMethod.Get,
"https://api.aniapi.com/v1/anime");
var client = httpClientFactory.CreateClient();
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
var response = await client.SendAsync(request);
ApiDataRoot apiDataRoot = null;
if (response.IsSuccessStatusCode)
{
var responseString = await response.Content.ReadAsStringAsync();
apiDataRoot = System.Text.Json.JsonSerializer.Deserialize<ApiDataRoot>(responseString);
}
else
{
apiDataRoot = new ApiDataRoot {status_code=400, message="error"};
}
return apiDataRoot;
}

类

public class ApiData
{
public int current_page { get; set; }
public int count { get; set; }
public List<Document> documents { get; set; }
public int last_page { get; set; }
}
public class ApiDataRoot
{
public int status_code { get; set; }
public string message { get; set; }
public ApiData data { get; set; }
public string version { get; set; }
}
public class Titles
{
public string en { get; set; }
public string jp { get; set; }
public string it { get; set; }
}

public class Descriptions
{
public string en { get; set; }
public string it { get; set; }
}
public class Document
{
public int anilist_id { get; set; }
public int mal_id { get; set; }
public int format { get; set; }
public int status { get; set; }
public Titles titles { get; set; }
public Descriptions descriptions { get; set; }
public DateTime start_date { get; set; }
public DateTime end_date { get; set; }
public int season_period { get; set; }
public int season_year { get; set; }
public int episodes_count { get; set; }
public int episode_duration { get; set; }
public string trailer_url { get; set; }
public string cover_image { get; set; }
public string cover_color { get; set; }
public string banner_image { get; set; }
public List<string> genres { get; set; }
public int score { get; set; }
public int id { get; set; }
public int? prequel { get; set; }
public int? sequel { get; set; }
}