https://blog.csdn.net/ibenxiaohai123/article/details/77453340

https://docs.microsoft.com/en-us/dotnet/api/system.security.cryptography.md5?redirectedfrom=MSDN&view=netcore-2.1

在.net 4.5版本下，使用System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile进行MD5加密时，会出现已过时

return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower();   //32位

return System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower().Substring(8, 16);  //16位

我们可以用下面的方法替代之：

public static string GetMd5Hash(string input)
        {
            MD5 md5Hash = MD5.Create();
 
            // Convert the input string to a byte array and compute the hash.
            byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
 
            // Create a new Stringbuilder to collect the bytes
            // and create a string.
            StringBuilder sBuilder = new StringBuilder();
 
            // Loop through each byte of the hashed data 
            // and format each one as a hexadecimal string.
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }
            // Return the hexadecimal string.
            return sBuilder.ToString();
        }