C# 如何使用HttpClient模拟请求

/// <summary>
/// 获取时间戳（毫秒）.
/// </summary>
/// <param name="dateTime"></param>
/// <returns></returns>
[HttpPost]
[AllowAnonymous]
[Route("DateTime/GetTimeStamp")]
public string GetTimeStamp([Required] MyDateTime dateTime)
{
  // 没有签名或者签名不匹配返回null.
  if (!Request.Headers.TryGetValue("X-Sign", out var xSign) || GenerateSign(dateTime) != xSign)
  {
    return $"签名{xSign}验证失败";
  }

  // 返回时间戳
  var time = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day, dateTime.Hour, dateTime.Minute, dateTime.Second);
  return ((time.ToUniversalTime().Ticks - 621355968000000000) / 1000).ToString();
}

/// <summary>
/// 自定义时间类.
/// </summary>
public class MyDateTime
{
  /// <summary>
  /// 年.
  /// </summary>
  public int Year { get; set; }

  /// <summary>
  /// 月.
  /// </summary>
  public int Month { get; set; }

  /// <summary>
  /// 日.
  /// </summary>
  public int Day { get; set; }

  /// <summary>
  /// 时.
  /// </summary>
  public int Hour { get; set; }

  /// <summary>
  /// 分.
  /// </summary>
  public int Minute { get; set; }

  /// <summary>
  /// 秒.
  /// </summary>
  public int Second { get; set; }
}

/// <summary>
/// 生成签名.
/// </summary>
/// <param name="dateTime"></param>
/// <returns></returns>
private async Task<string> GenerateSign(MyDateTime dateTime)
{
  // 利用反射获取属性及对应的值，根据key的Name排序
  var properties = dateTime.GetType().GetProperties().OrderBy(e => e.Name);

  // 使用一个字典来存放
  var signDic = new Dictionary<string, string>();
  foreach (var property in properties)
  {
    var key = property.Name;
    var value = property.GetValue(dateTime)&#63;.ToString();

    signDic.Add(key, value);
  }

  // 用UrlEncoded处理
  var sign = await new FormUrlEncodedContent(signDic).ReadAsStringAsync().ConfigureAwait(false);

  // 返回MD5加密后的结果
  return Convert.ToBase64String(new MD5CryptoServiceProvider().ComputeHash(Encoding.UTF8.GetBytes(sign)));
}

// 创建HttpClient实例
var httpClient = new HttpClient();

// 请求的时间，2020-10-01 08:10:30
var requestTime = new MyDateTime
{
  Year = 2020,
  Month = 10,
  Day = 1,
  Hour = 8,
  Minute = 10,
  Second = 30,
};

// 设置HttpRequestMessage中的Content。
// 请求入参，我们接口定义的入参是dateTime，所以这里的Key也是dateTime
var requestDic = new Dictionary<string, string>();
requestDic.Add("dateTime", JsonConvert.SerializeObject(requestTime));
var encodedContent = await new FormUrlEncodedContent(requestDic).ReadAsStringAsync().ConfigureAwait(false);
var httpContent = new StringContent(encodedContent, Encoding.UTF8, "application/x-www-form-urlencoded");

// 添加签名头
var sign = await GenerateSign(requestTime);
httpContent.Headers.Add("X-Sign", sign);

// 生成Request的Message
var httpRequestMessage = new HttpRequestMessage
{
  Method = HttpMethod.Post, // 请求方式
  RequestUri = new Uri("http://localhost:5000/DateTime/GetTimeStamp"), // 请求地址
  Content = httpContent, // 请求内容
};

// 在HttpRequestMessage中可以任意的添加请求头
httpRequestMessage.Headers.Add("GitHub", "XgHao");

// 发送请求
var response = await httpClient.SendAsync(httpRequestMessage).ConfigureAwait(false);
var timeStamp = await response.Content.ReadAsStringAsync().ConfigureAwait(false);