键值对排序并MD5加密

public static class CreateSign
{
public static string SignTopRequest(IDictionary<string, string> parameters, string secret)
{
return SignTopRequest(parameters, secret, true);
}
public static string SignTopRequest(IDictionary<string, string> parameters, string secret, bool qhs)
{
// 第一步：把字典按Key的字母顺序排序
IDictionary<string, string> sortedParams = new SortedDictionary<string, string>(parameters);
IEnumerator<KeyValuePair<string, string>> dem = sortedParams.GetEnumerator();

// 第二步：把所有参数名和参数值串在一起
StringBuilder query = new StringBuilder(secret);
while (dem.MoveNext())
{
string key = dem.Current.Key;
string value = dem.Current.Value;
if (!string.IsNullOrEmpty(key) && !string.IsNullOrEmpty(value))
{
query.Append(key).Append(value);
}
}
if (qhs)
{
query.Append(secret);
}

// 第三步：使用MD5加密
MD5 md5 = MD5.Create();
byte[] bytes = md5.ComputeHash(Encoding.UTF8.GetBytes(query.ToString()));

// 第四步：把二进制转化为大写的十六进制
StringBuilder result = new StringBuilder();
for (int i = 0; i < bytes.Length; i++)
{
string hex = bytes[i].ToString("X");
if (hex.Length == 1)
{
result.Append("0");
}
result.Append(hex);
}

return result.ToString();
}