Chap05 C # advanced type

ArticleDirectory

• For delegated operations (+,-), multicast delegation:
• Anonymous delegation:
• Declaration method:
• Enumeration type as a bit flag

1. Delegate

Refer to the built-in vs2010 example.

For the delegate operation (+,-), multicast delegate: anonymous delegate:

 

2. Events

 
1. define a string list class (inherited from list <string>) 2. define delegation 3. define events based on delegation 4. define the method of event triggering 5. define the event processing function 6. subscription
 

 Namespace  Myevent {  Class  Program {  Class Stringlist: List < String > {  Public  Delegate   Void  Dele ();  Public   Event Dele changed; //  Event definition (with delegation)              Public   New   Void Add ( String Item) //  Use new to hide methods in the base class  {  Base . Add (item );//  Call methods in the base class Changed (); //  Event-triggered  }}  ///   <Summary>          ///  Event processing functions  ///   </Summary>          Static   Void  Listchanged () {console. writeline (  " Listchanged_add  "  );}  Static   Void Main ( String  [] ARGs) {stringlist names = New  Stringlist (); names. Changed + = Listchanged; //  Event subscription Names. Add ( "  Tom  " ); Names. Add (  "  Jim  "  ); Names. Add (  "  Lily  "  );}}}
 

3. Structure-C-language gifts

• Fields, attributes, and methods that can be declared in struct.
• The structure is the value type, and the class is the reference type.

4. sealing and Division

• Sealed class: class that cannot be inherited
• Partial class: place a long class in different files.

5. Enumeration type declaration method:

Enum days {Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };

Enum months: byte {Jan, Feb, MAR, APR, May, Jun, Jul, Aug, SEP, Oct, Nov, Dec };

By default, the basic type of each element in the enumeration is int. You can use a colon to specify another Integer type, as shown in the preceding example.

Enumeration type as a bit flag

 [Flags]  Enum  Days2 {none = 0x0  , Sunday = 0x1 , Monday = 0x2  , Tuesday = 0x4  , Wednesday = 0x8  , Thursday = 0x10  , Friday = 0x20  , Saturday = 0x40  }  Class Myclass {days2 meetingdays = Days2.tuesday | Days2.thursday ;} 

The following operators can be used: Or (|), XOR (^), and (&).

 //  Initialize with two flags using bitwise OR. Meetingdays = days2.tuesday | Days2.thursday;  //  Set an additional flag using bitwise OR. Meetingdays = meetingdays | Days2.friday; console. writeline (  "  Meeting days are {0}  " , Meetingdays );  //  Output: meeting days are Tuesday, Thursday, Friday  //  Remove a flag using bitwise XOR. Meetingdays = meetingdays ^ Days2.tuesday; console. writeline (  "  Meeting days are {0}  "  , Meetingdays );  //  Output: meeting days are Thursday, Friday  // Test Value of flags using bitwise AND.  Bool Test = (meetingdays & days2.thursday) = Days2.thursday; console. writeline (  "  Thursday {0} A meeting day.  " , Test = True ? "  Is  " : "  Is not  "  ); //  Output: Thursday is a meeting day.