The 120-day 1200-hour transmission of wisdom in junior students. NET (ii)

A few days ago to help people to make a social networking site, or the old-fashioned way of control, but after learning Ajax and general processing program ASHX, also used in some, today back to continue to write blog. Continue the last summary of the basic knowledge, learn more content, summary may be more messy, sub-article summary for the usual can see for themselves.

1, the file stream FileStream than the file class faster, do not occupy memory. Use file streams to manipulate large files.

2, File stream resource, GC will not help us release, need to release manually.

3, when the process of creating an object is written in using, the resource is freed automatically.

4, if in a subclass, the member name is written in the same way as the parent class, this hides the subclass from the parent class, and the effect is that the child class ' point ' is not a member of the parent class.

5, let an object show that the state of multiple objects is called polymorphism.

6, three kinds of means to realize polymorphism: virtual method, abstract class, interface.

7, abstract functions must have no method body, abstract functions must be in the abstract class.

8, when the parent class function has no meaning, it is necessary to use the abstract class, if this function we know what content, and need to call, must use virtual method.

9, tag the parent element virtual, which indicates that the function can be overridden by a quilt class. Add override before the subclass function to represent the method of the parent class.

10, whether it is a virtual method or an abstract class, we implement polymorphism by declaring the parent class member, pointing to the object of a subclass. Father F=new Son ();

11, the abstract member access modifier cannot be private.

12, an abstract class can contain instance members.

13, the abstract class has a constructor function.

14,partial class is a partial class, which divides the class into several and uses a lot.

15, to achieve polymorphism: Reduce code redundancy, so that the program is more scalable to meet the changing needs.

16, the interface emphasizes a specification, the interface can be likened to a ' capability ', the function of the interface and the function of the abstract class have the same meaning, all means "deeds"; interface is called implementation. You can inherit multiple interfaces.

17, to implement the subclass of the interface, all members must be implemented.

18, the base class must be placed before the interface.

19, the process is made up of multiple threads.

20, a server at least two sockets, the first is to listen to whether the client wants to connect; the second socket is responsible for communicating with the client.

21,TCP Three-time handshake (streaming socket): Data is stable and less efficient. "1, Are you free?" 2, free; 3, I know you are free ";

22,UDP (Datagram socket): High efficiency, data instability. "Whether it's free or not, pass the data directly."

23, Port 1 to 65535, preferably after 1024.

24, the function that the thread executes, the grammatical requirement must be object;

25,div a little bit faster than table,div. You can download one display and the table will be fully downloaded to display. Table is no longer used in XHTML site standards.

26, declaring variables is best given null because "" takes up memory.

The 120-day 1200-hour transmission of wisdom in junior students. NET (ii)