Research on development technology of Delphi.NET multilayer application system

Since last week, a friend asked me why I did not update the blog for a long time, in fact, I think I wrote a blog has been very diligent, this more than 10 days did not update the blog is taken for granted, I began to travel again. Last week, Taiwan conducted "delphi.net multi-tier application system Development Technology Seminar", after the Devco in Taiwan 1, 2 months later, it is true that some slowly some customers began to return to attend the seminar, which is a good phenomenon, It also gives me the opportunity to talk to some of my friends about their work and what topics they want to hear. The reason why DEVCO will be held last week "delphi.net multi-tier application Development Technology Seminar" is because many friends are asking how to migrate applications to. NET and how to enable them to use ASP.net to develop new Web applications but also to be able to use existing MIDAS/DATASNAP applications at the same time.

Actually to make the new. NET application system and existing MIDAS/DATASNAP application system it is not difficult to get together, the problem to be solved is just let. NET client calls to the MIDAS/DATASNAP application system and how to transform data patterns in two execution environments.

Use. NET INTEROP2 technology can make the. NET client call to the MIDAS/DATASNAP application system, the data form conversion is a little difficult. The simplest idea is to have both sides use XML to exchange data, but the only trouble is that midas/datasnap encapsulates data in many ways in a olevariant form, so. NET clients must know how to handle the Olevariant data packets passed by MIDAS/DATASNAP and extract real data in XML encapsulation from them.

Fortunately, we can in the Delphi "hidden" document found a glimmer of dawn: