Delphi 5 to Delphi 10.1

[Dominique Phaneuf 0]

Hi,

 

I migrate a apps from delphi 5 using TWSocket 5.25  to delphi 10.1 using TWSocket 8.57.   We have 2 programme one that we trying to migrate to delphi 10.1 (means unicode now) the client, and the server that is still in delphi 5 (means still ansi ascii).  When we use the program convert to Delphi 10.1 look like when doing the sendstr i see in the code that it's doing a AnsiString because of this normaly the string send to the delph  5 must be accurate, but look like it's not able to recognize it properly....  Any idean on a way to make it working in the hybrid  way (delphi 5 and 10.1) or i will need to convert both of them do delphi 10.1 at the same time?

 

 

Thanks,

 

[Lars Fosdal 1792]

Are you using the appropriate code page for your ansistring? Can you give an example of what goes wrong, character-wise? 

[Dominique Phaneuf 0]

Forget it, i thinking that it`s in the udp because this append between the exchange and i have a error after it, but the problem  it`s somewhere else.

Thanks,

[Lars Fosdal 1792]

UDP is per definition not reliable.

[Markus Kinzler 174]

9 minutes ago, Lars Fosdal said:

UDP is per definition not reliable.

This statement could be misunderstood. UDP is connectionless in itself, but this could be done by higher level protocols. In bad conditions (bad network connection) the udp based tftp is much more reliable as ftp, which is a based on tcp.

[Lars Fosdal 1792]

@Markus Kinzler - What I meant is that in UDP, there is no mechanism the ensures that the packet reaches its destination, nor is there a mechanism that allows the recipient to discover that a packet has gone missing.

As you say, all of that would have to be implemented as a protocol on top of UDP.

When it comes to the content, I actually don't know if UDP ensures that the content of a delivered package is guaranteed to be intact? I would tend to assume so, but I haven't actually checked.