XCode 下的开发 类的方法扩展 读书日志记录1.

@interface Fraction : NSObject {

int numerator;

int denominator;

}

-(Fraction*) initWithNumerator:(int)n denominator:(int)d;

-(int) numerator;

-(int) denominator;

-(void) print;

-(void) setNumerator:(int)n;

-(void) setDenominator:(int)n;

-(void) setNumeratorAndDenominator:(int) num

andDeno:(int) den;

@end

--------------------

@implementation Fraction

-(int) numerator{

return numerator;

}

-(int) denominator

{

return denominator;

}

-(void) print

{

printf("%i--%i/r", numerator, denominator);

}

-(void) setNumerator:(int)n

{

numerator=n;

}

-(void) setDenominator:(int)n

{

denominator=n;

}

-(void) setNumeratorAndDenominator:(int) num

andDeno:(int) den

{

numerator=num;

denominator=den;

}

-(Fraction*) initWithNumerator:(int)n denominator:(int)d

{

self=[super init];

if(self)

{

[self setNumeratorAndDenominator:n andDeno:d ];

}

return self ;

}

@end

---------------------静态扩展方法--------------

@interface Fraction (Math)

-(Fraction*) add: (Fraction*) f;

-(Fraction*) mul: (Fraction*) f;

-(Fraction*) div: (Fraction*) f;

-(Fraction*) sub: (Fraction*) f;

@end

#import "FractionMath.h"

@implementation Fraction (Math)

-(Fraction*) add: (Fraction*) f {

int num= numerator + [f numerator] ;

int deo= denominator + [ f denominator];

return [[Fraction alloc] initWithNumerator: num denominator: deo];

}

-(Fraction*) sub: (Fraction*) f {

return [[Fraction alloc] initWithNumerator: numerator - [f numerator]

denominator: denominator - [f denominator]];

}

-(Fraction*) mul: (Fraction*) f {

return [[Fraction alloc] initWithNumerator: numerator * [f numerator]

denominator: denominator * [f denominator]];

}

-(Fraction*) div: (Fraction*) f {

return [[Fraction alloc] initWithNumerator: numerator % [f numerator]

denominator: denominator % [f denominator]];

}

@end

--------------------有点类似于C# 里的

pubic static void ExecCmd(this Sqlconnection cnn ,string cmdText)

{

/////////////

}