public string SignEncrypt(string value)
    {
        try
        {
            X509Certificate2 pc = new X509Certificate2(AppDomain.CurrentDomain.BaseDirectory + "\\qlsm123.pfx", "20181107");
            RSACryptoServiceProvider p = (RSACryptoServiceProvider)pc.PrivateKey;
            byte[] enBytes = p.SignData(Encoding.UTF8.GetBytes(value), new SHA1CryptoServiceProvider());
            p.Dispose();
            return Convert.ToBase64String(enBytes);
        }
        catch (Exception e)
        {
            //处理异常
        }
        return string.Empty;
    }