C# 从 HTTP 请求接收 JSON 数据

Receiving JSON data back from HTTP request

提问by user516883

I have a web request that is working properly, but it is just returning the status OK, but I need the object I am asking for it to return. I am not sure how to get the json value I am requesting. I am new to using the object HttpClient, is there a property I am missing out on? I really need the returning object. Thanks for any help

我有一个正常工作的 Web 请求，但它只是返回状态 OK，但我需要我要求它返回的对象。我不确定如何获取我请求的 json 值。我是使用对象 HttpClient 的新手，是否有我遗漏的属性？我真的需要返回的对象。谢谢你的帮助

Making the call - runs fine returns the status OK.

进行调用 - 运行良好返回状态 OK。

HttpClient client = new HttpClient();
client.DefaultRequestHeaders.Accept
  .Add(new MediaTypeWithQualityHeaderValue("application/json"));
var responseMsg = client.GetAsync(string.Format("http://localhost:5057/api/Photo")).Result;

The api get method

api获取方法

//Cut out alot of code but you get the idea
public string Get()
{
    return JsonConvert.SerializeObject(returnedPhoto);
}

采纳答案by Panagiotis Kanavos

If you are referring to the System.Net.HttpClient in .NET 4.5, you can get the content returned by GetAsync using the HttpResponseMessage.Contentproperty as an HttpContent-derived object. You can then read the contents to a string using the HttpContent.ReadAsStringAsyncmethod or as a stream using the ReadAsStreamAsyncmethod.

如果您指的是 .NET 4.5 中的 System.Net.HttpClient，则可以使用HttpResponseMessage.Content属性作为HttpContent派生对象获取 GetAsync 返回的内容。然后，您可以使用HttpContent.ReadAsStringAsync方法将内容读取为字符串，或使用ReadAsStreamAsync方法将内容读取为流。

The HttpClientclass documentation includes this example:

的HttpClient的类文件包括该实施例中：

  HttpClient client = new HttpClient();
  HttpResponseMessage response = await client.GetAsync("http://www.contoso.com/");
  response.EnsureSuccessStatusCode();
  string responseBody = await response.Content.ReadAsStringAsync();

回答by Wouter Vanherck

Building on @Panagiotis Kanavos' answer, here's a working method as example which will also return the response as an object instead of a string:

基于@Panagiotis Kanavos的回答，这里有一个工作方法作为示例，它也将响应作为对象而不是字符串返回：

using System.Text;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json; // Nuget Package

public static async Task<object> PostCallAPI(string url, object jsonObject)
{
    try
    {
        using (HttpClient client = new HttpClient())
        {
            var content = new StringContent(jsonObject.ToString(), Encoding.UTF8, "application/json");
            var response = await client.PostAsync(url, content);
            if (response != null)
            {
                var jsonString = await response.Content.ReadAsStringAsync();
                return JsonConvert.DeserializeObject<object>(jsonString);
            }
        }
    }
    catch (Exception ex)
    {
        myCustomLogger.LogException(ex);
    }
    return null;
}

Keep in mind that this is only an example and that you'd probably would like to use HttpClientas a shared instance instead of using it in a using-clause.

请记住，这只是一个示例，您可能希望将其HttpClient用作共享实例，而不是在 using 子句中使用它。

回答by James Heffer

What I normally do, similar to answer one:

我通常会做什么，类似于回答一：

var response = await httpClient.GetAsync(completeURL); // http://192.168.0.1:915/api/Controller/Object

if (response.IsSuccessStatusCode == true)
    {
        string res = await response.Content.ReadAsStringAsync();
        var content = Json.Deserialize<Model>(res);

// do whatever you need with the JSON which is in 'content'
// ex: int id = content.Id;

        Navigate();
        return true;
    }
    else
    {
        await JSRuntime.Current.InvokeAsync<string>("alert", "Warning, the credentials you have entered are incorrect.");
        return false;
    }

Where 'model' is your C# model class.

其中“模型”是您的 C# 模型类。

回答by Greg Z.

I think the shortest way is:

我认为最短的方法是：

var client = new HttpClient();
string reqUrl = $"http://myhost.mydomain.com/api/products/{ProdId}";
var prodResp = await client.GetAsync(reqUrl);
if (!prodResp.IsSuccessStatusCode){
    FailRequirement();
}
var prods = await prodResp.Content.ReadAsAsync<Products>();

回答by bulbul bd

It's working fine for me by the following way -

通过以下方式对我来说效果很好 -

public async Task<object> TestMethod(TestModel model)
    {
        try
        {
            var apicallObject = new
            {
                Id= model.Id,
                name= model.Name
            };

            if (apicallObject != null)
            {
                var bodyContent = JsonConvert.SerializeObject(apicallObject);
                using (HttpClient client = new HttpClient())
                {
                    var content = new StringContent(bodyContent.ToString(), Encoding.UTF8, "application/json");
                    content.Headers.ContentType = new MediaTypeHeaderValue("application/json");
                    client.DefaultRequestHeaders.Add("access-token", _token); // _token = access token
                    var response = await client.PostAsync(_url, content); // _url =api endpoint url
                    if (response != null)
                    {
                        var jsonString = await response.Content.ReadAsStringAsync();

                        try
                        {
                            var result = JsonConvert.DeserializeObject<TestModel2>(jsonString); // TestModel2 = deserialize object
                        }
                        catch (Exception e){
                            //msg
                            throw e;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        return null;
    }