C# 调用网易“易盾” Web API

易盾是网易推出的反垃圾云服务，最近准备试用一下，但发现api文档中只提供了Java, Python, PHP的示例代码，却没有C#的示例代码，于是参照Java示例代码用C#实现了一下。

Java中用HashMap构建公共参数与私有参数，C#中则可以用Dictionary：

var parameters = new Dictionary<string, string>();
//公共参数
parameters.Add("secretId", "{secretId}");
parameters.Add("businessId", "{businessId}");
parameters.Add("version", "v2");
parameters.Add("timestamp", CurrentTimeMillis().ToString());
parameters.Add("nonce", new Random().Next().ToString());
//私有参数
parameters.Add("dataId", Guid.NewGuid().ToString());
parameters.Add("content", content);
parameters.Add("dataOpType", "1");
parameters.Add("ip", ip); 

Java中用 System.currentTimeMillis() 生成 timestamp，C#中没有直接的对应实现，只能另外实现一个（来自C# 实现 Java 的 System.currentTimeMillis() 值）：

private long CurrentTimeMillis()
{
    return (long)(DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;
}

对于生成签名的操作，Java中稍显复杂，C#中用Lambda一气呵成：

private string GenerateSignature(Dictionary<string, string> parameters, string secretKey)
{
    var signatueString = string.Join(string.Empty,
        parameters.OrderBy(p => p.Key).Select(p => p.Key + p.Value))
        + secretKey;

    return string.Join(string.Empty,
        MD5.Create().ComputeHash(Encoding.UTF8.GetBytes(signatueString)).Select(s => s.ToString("x2")));
}

对于http请求操作，Java中有HttpClient，C#中也有：

var response = await _httpClient.PostAsync("/v2/text/check", 
    new FormUrlEncodedContent(parameters));

对于响应结果解析，Java中有JsonParser，C#中有Json.NET：

var responseText = await response.Content.ReadAsStringAsync();
var jObject = JObject.Parse(responseText);
var statusCode = jObject["code"].Value<int>();
if (statusCode == 200)
{
    var action = jObject["result"]["action"].Value<int>();
    return action == 1;
}
else
{
    return false;
}

完整实现代码如下：

public class YiDunCheckSpam : ICheckSpam
{
    private const string BASE_ADDRESS = "https://api.aq.163.com/";
    private readonly HttpClient _httpClient;

    public YiDunCheckSpam()
    {
        _httpClient = new HttpClient();
        _httpClient.BaseAddress = new Uri(BASE_ADDRESS);
    }

    public async Task<bool> IsSpamPost(string title, string content, string author, string ip)
    {
        var parameters = new Dictionary<string, string>();
        //公共参数
        parameters.Add("secretId", "{secretId}");
        parameters.Add("businessId", "{businessId}");
        parameters.Add("version", "v2");
        parameters.Add("timestamp", CurrentTimeMillis().ToString());
        parameters.Add("nonce", new Random().Next().ToString());
        //私有参数
        parameters.Add("dataId", Guid.NewGuid().ToString());
        parameters.Add("content", content);
        parameters.Add("dataOpType", "1");
        parameters.Add("ip", ip);
        parameters.Add("title", title);
        parameters.Add("nickname", author);

        var secretKey = "{secretKey}";
        var signature = GenerateSignature(parameters, secretKey);
        parameters.Add("signature", signature);

        var response = await _httpClient.PostAsync("/v2/text/check",
            new FormUrlEncodedContent(parameters));

        var responseText = await response.Content.ReadAsStringAsync();
        var jObject = JObject.Parse(responseText);
        var statusCode = jObject["code"].Value<int>();
        if (statusCode == 200)
        {
            var action = jObject["result"]["action"].Value<int>();
            return action > 1;
        }
        else
        {
            return false;
        }
    }

    private string GenerateSignature(Dictionary<string, string> parameters, string secretKey)
    {
        var signatueString = string.Join(string.Empty,
            parameters.OrderBy(p => p.Key).Select(p => p.Key + p.Value))
            + secretKey;

        return string.Join(string.Empty,
            MD5.Create().ComputeHash(Encoding.UTF8.GetBytes(signatueString)).Select(s => s.ToString("x2")));
    }

    private long CurrentTimeMillis()
    {
        return (long)(DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;
    }
}