FormsAuthentication.HashPasswordForStoringInConfigFile 方法是一个在.NET 4.5中已经废弃不用的API，参见:

https://msdn.microsoft.com/zh-cn/library/system.web.security.formsauthentication.hashpasswordforstoringinconfigfile(v=vs.110).aspx

This is a solution for SH1 variant.

     public static string GetSwcSH1(string value)

     {

        SHA1 algorithm = SHA1.Create();

        byte[] data = algorithm.ComputeHash(Encoding.UTF8.GetBytes(value));

        string sh1 = "";

        for (int i = ; i < data.Length; i++)

        {

            sh1 += data[i].ToString("x2").ToUpperInvariant();

        }

        return sh1;

     }

For MD5 you only change algorithm to:

MD5 algorithm = MD5.Create();

参考：http://*.com/questions/13527277/drop-in-replacement-for-formsauthentication-hashpasswordforstoringinconfigfile