命名空间：VOL.Core.Extensions
类：ObjectExtension
增加方法：IsBase64String
public static bool IsBase64String(this string base64String)
{
const int bitsEncodedPerChar = 6;
int bytesExpected = (base64String.Length * bitsEncodedPerChar) >> 3;
Span bytesBuffer = stackalloc byte[bytesExpected];
return Convert.TryFromBase64String(base64String, bytesBuffer, out int bytesWritten);
}

命名空间：VOL.Core.Extensions
类：SecurityEncDecryptExtensions
方法：DecryptDES
增加入参判断，优于上下文try catch
if (decryptString.IsNullOrWhiteSpace()|| decryptKey.IsNullOrWhiteSpace() || !decryptString.IsBase64String())
{
return decryptString;
}