VB. NET, what have you learned (one)

What have you learned when you reconstruct the billing system of the VB. NET data center? When I started the second Rebuild of the data room charging system, I found that I had come into contact with a lot of things I did not know before and learned a lot of new knowledge. next I will give a one-to-one example of what I learned when I reconstructed the charging system in the IDC room for the second time ----

1. UML diagram 2, three-tier architecture 3, sqlhelper 4, Configuration File 5, interface 6, design mode

In the following articles, I will focus on the new knowledge I learned in. Net <personal Rebuild of the IDC billing system>.

Think about our first Data room charging system, which is purely for the purpose of implementing functions. Now we start to use. net for personal restructuring, and have learned a lot of new knowledge and come into contact with a lot of new content. This article begins with a UML diagram.

I wrote a blog about UML diagrams some time ago, that is, when I first used three layers to reconstruct the charging system of the data center, I really felt that it was difficult and there were a lot of problems in drawing. If you are interested, you can check out my previous blog:Individual restructuring of the data room charging system-lots of questions on Drawing. Because I have learned UML knowledge before, and I have learned three layers of knowledge, I feel that I can figure out what is included in the graph. However, I can't start to draw a picture. For example, on the u layer, I know that from the perspective of the three-tier architecture, the U layer receives data from the front-end interface, however, I don't know what to put in the class diagram of the U layer, so I took out the "user" and put it on the u layer. There were really a lot of twists and turns in the drawing experience. I tried it for a while. I also asked my students how many times I had to ask them. Later I thought I had to figure out the path. I think a lot of students entering the personal version refactoring will encounter such problems when drawing UML diagrams?

However, the result is always good. After a period of time, I have mastered the painting skills. For us, the difficulty of drawing is the class diagram and the sequence diagram. Other types of pictures, such as the package diagram, can also be used, as long as the three-layer knowledge is good, the packet graph is not a problem, but it is worth noting that the packet graph is really important. It involves the reference relationship between each layer. This really needs to be clarified, otherwise, some will suffer.

This article will be written here today. I will post my achievements in the personal Rebuild of the data center billing system one after another, so stay tuned!