C # event-based Attribute value changes

first, create a person class. Assume that the change of the property name in the person class is detected through events.

Private StringName;Public StringName {Get{Return This. Name ;}Set{If(Value! =This. Name) {whenvaluechange ();}This. Name =Value ;}}
 

The whenvaluechange () method is executed when the attribute name changes;

 ///  /Define the delegate     Public   Delegate   Void Delvaluechange ( Object  Sender, eventargs E );  //  Events associated with Delegation  Public   Event  Delvaluechange onvaluechanged;  Public   Void  Whenvaluechange (){ If (Onvaluechanged! = Null  ) {Onvaluechanged (  This , Null  );}} 

Compile the test class:

 Static   Void Main ( String  [] ARGs) {person P = New  Person (); p. Name = " Zhang San  "  ; Console. writeline (P. Name); p. onvaluechanged + = New  Delvaluechange (p_onvaluechanged); p. Name = "  Test  "  ; Console. Readline ();}  Static   Void P_onvaluechanged ( Object  Sender, eventargs e) {console. writeline ( "  Attribute Value changed  "  );} 

Run: