/// <summary>
/// 微信认证URL
/// </summary>
/// <param name="signature"></param>
/// <param name="timestamp"></param>
/// <param name="nonce"></param>
/// <param name="echostr"></param>
/// <returns></returns>
public static string CheckURL(string signature, string timestamp, string nonce, string echostr)
{
var re = CommonBLL.CheckSignature(signature, timestamp, nonce) ? echostr : "";
return(re);
}