如何使用 httpclient c# 调用 bitly v4 api 以缩短 url？

Question

So I want call Bitly API to shorten URL I am able to get response using POSTMAN and Jquery but not able to get response using C#.

工作 Jquery 代码：

<script type="text/javascript">
$(function () {
    $(".createBitly").on("click", function (e) {

        e.preventDefault();

        var url = "https://stackoverflow.com/questions/ask";
        var accessToken = "550ea49c78208978cbeb85ef24XXXX49874cc097";

        var params = {
            "long_url": url
        };

        $.ajax({
            url: "https://api-ssl.bitly.com/v4/shorten",
            cache: false,
            dataType: "json",
            method: "POST",
            contentType: "application/json",
            beforeSend: function (xhr) {
                xhr.setRequestHeader("Authorization", "Bearer " + accessToken);
            },
            data: JSON.stringify(params)
        }).done(function (data) {
            console.log(data);

        }).fail(function (data) {
            console.log(data);
        });
    });
});
</script>

C# 代码我正在尝试但无法使用 C# 实现：

        using (var client = new HttpClient())
        {
            client.DefaultRequestHeaders.Accept.Clear();
            client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "550ea49c78208978cbeb85ef24XXXX49874cc097");
            var content = new
            {
                long_url = "https://stackoverflow.com/questions/ask"
            };
            var model = JsonConvert.SerializeObject(content);
            
            //HTTP POST
            var postTask = client.PostAsJsonAsync("https://api-ssl.bitly.com/v4/shorten", model);
            postTask.Wait();

            var result = postTask.Result;

        }

现在得到响应成功但没有得到真正想要的数据。

我想要像进入 Postman 这样的回应

如何使用 C# 实现此目的，我们将不胜感激。 提前致谢

Answer 1

您上面共享的代码中有两个问题。

1. 授权头

// This line of code ends up adding an incorrect header that looks like this: 
// Authorization: Authorization Bearer <myAccessToken>
client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", "<myAccessToken>");

// Instead, try this
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", $"Bearer <myAccessToken>");

2. 请求正文 PostAsJsonAsync 将第二个参数序列化为一个 json。 所以，你不应该序列化content 。 而是将名为content的对象作为第二个参数发送。

下面是我尝试过的示例代码，它可以工作：

var client = new HttpClient();
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", $"Bearer {myAccessToken}");

var content = new
{
    long_url = "https://stackoverflow.com/questions/ask"
};
        
//HTTP POST
var resp = await client.PostAsJsonAsync("https://api-ssl.bitly.com/v4/shorten", content);
Console.WriteLine(await resp.Content.ReadAsStringAsync());

Answer 2

我找到了解决方案，抱歉没有发布希望它会有所帮助。

public static class BitlyShortUrl
{

    private readonly static string _token = ConfigurationManager.AppSettings["BitlyToken"].ToString();

    public static string ShortenAsync(string longUrl)
    {
        try
        {
            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls
                                                   | SecurityProtocolType.Tls11
                                                   | SecurityProtocolType.Tls12
                                                   | SecurityProtocolType.Ssl3;

            var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://api-ssl.bitly.com/v4/shorten");
            httpWebRequest.Headers.Add("Authorization", "Bearer " + _token);
            httpWebRequest.ContentType = "application/json";
            httpWebRequest.Method = "POST";

            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                string json = "{\"long_url\":\"" + longUrl + "\"}";

                streamWriter.Write(json);
            }

            var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                var result = streamReader.ReadToEnd();

                if (httpResponse.StatusCode == HttpStatusCode.OK)
                {
                    dynamic jsonResponse = JObject.Parse(result);
                    return jsonResponse.link;
                }
                else if (httpResponse.StatusCode == HttpStatusCode.Created)
                {
                    dynamic jsonResponse = JObject.Parse(result);
                    return jsonResponse.link;
                }
                else
                {
                    return longUrl;
                }
            }
        }
        catch (WebException ex)
        {
            return ex.Message;
        }
    }
}