public string Generate(WeChatParameters parameters, HashAlgorithm hashAlgorithm, string apiKey = null)
{
var signStr = $"{parameters.GetWaitForSignatureStr()}{(apiKey != null ? $"&key={apiKey}" : "")}";
var signBytes = hashAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(signStr));
var sb = new StringBuilder();
foreach (var @byte in signBytes)
{
sb.Append($"{@byte:x2}");
}
return(sb.ToString().ToUpper());
}