AC

Hi Olman, Thanks for your reply. Regards. Alex

I wrote the following code in my Windows Phone Silverlight 8.1 project： internal class MD5Managed : HashAlgorithm { private ABCDStruct _abcd; ... ... public MD5Managed() { HashSizeValue = 0x80; Initialize(); } public override sealed void Initialize() { ... ... } } As you see, I inherit System.Security.Cryptography.HashAlgorithm class. After I use "Silverlight bridge to UWP" to convert my project to uwp, the app cannot run, it shows message "The type or namespace name could not be found (are you missing a using directive or an assembly reference", What should I do? ThanksAlex