objective-c简陋学习-源码笔记-白红宇

objective-c简陋学习-源码笔记

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发布时间：2019-06-22

本文共 20746 字，大约阅读时间需要 69 分钟。

本文是学习时的一些代码。

Fraction.h

#import 
    
       Fraction:NSObject {    int numerator;    int denominator;}-(Fraction*) initWithNumerator:(int) n denominator:(int) d;-(void) print;-(void) setNumerator: (int) n;-(void) setDenominator: (int) d;-(void) setNumerator:(int)n andDenominator: (int)d;//-(void) setNumerator:(int)n : (int)d;-(int) numerator;-(int) denominator;

Fraction.m

#import "Fraction.h"#import 
    
     @implementation Fraction-(Fraction*) initWithNumerator:(int) n denominator:(int) d{    self = [super init];    if(self){	[self setNumerator: n andDenominator: d];    }}-(void) print{    printf("%i/%i", numerator, denominator);}-(void) setNumerator: (int) n {    numerator = n;}-(void) setDenominator: (int) d {    denominator = d;}-(void) setNumerator:(int)n andDenominator: (int)d{    numerator = n;    denominator = d;}// -(void) setNumerator:(int)n: (int)d{//     numerator = n;//     denominator = d;// }-(int) denominator{    return denominator;}-(int) numerator{    return numerator;}   Fraction(Private)-(void) privateMethod; @implementation Fraction(Private)-(void) privateMethod{    printf("-----privateMethdo\n");}

#if 0#import 
    
     #import "Fraction.h"int main(int argc, char **argv) {    Fraction *frac = [[Fraction alloc] init];    Fraction *frac2 = [[Fraction alloc] init];    Fraction *frac3 = [[Fraction alloc] initWithNumerator: 3 denominator: 10];            [frac setNumerator: 1];    [frac setDenominator: 3];        [frac2 setNumerator: 1 andDenominator: 5];    printf("The fraction is :");    [frac print];    printf ("\n");        printf("The fraction2 is :");    [frac2 print];    printf ("\n");    printf("The fraction3 is :");    [frac3 print];    printf ("\n");        [frac release];    return 0;}#endif#if 0#import 
     
        Access:NSObject{     int publicVar;     int privateVar;    int privateVar2;     int protectedVar;} @implementation Access int main(){    Access *a = [[Access alloc] init];        a->publicVar = 5;    printf("public var: %i\n", a->publicVar);        //a->protectedVar = 1;        [a release];    return 0;}#endif///#if 0#import 
      
       //#import 
       
        static int count;  ClassA: NSObject+(int) initCount;+(void) initialize; @implementation ClassA-(id) init{    printf("ClassA init\n");    self = [super init];    count++;    return self;}+(int) initCount{    printf("ClassA initCount\n");    return count;}+(void) initialize{    printf("ClassA initialize\n");    count = 0;} int main(){    ClassA *class1 = [[ClassA alloc] init];    ClassA *class2 = [[ClassA alloc] init];        printf("ClassA count=%i\n", [ClassA initCount]);        ClassA *class3 = [[ClassA alloc] init];        printf("ClassA count = %i \n", [ClassA initCount]);//     printf("class1 count = %i \n", [class1 initCount]);//     printf("class2 count = %i \n", [class2 initCount]);//     printf("class3 count = %i \n", [class3 initCount]);//      NSLog(@"hello");    [class1 release];    [class2 release];    [class3 release];    return 0;}#endif//异常处理#if 0#import 
        
         #import 
         
          #import 
          
            CupWarningException:NSException @implementation CupWarningException CupOverflowException:NSException @implementation CupOverflowException Cup: NSObject{ int level;}-(int) level;-(void) setLevel: (int) l;-(void) fill;-(void) empty;-(void) print; @implementation Cup-(id) init{ self = [super init]; if(self){ [self setLevel: 0]; } return self;}-(int) level{ return level;}-(void) setLevel:(int) l{ level = l; NSLog(@"setLevel in : %d", l); if(level > 100){ // throw overflow NSException *e = [CupOverflowException exceptionWithName: @"CupOverflowException" reason: @"The level is > 100" userInfo: nil ]; @throw e; }else if(level >= 50){ NSException *e = [CupWarningException exceptionWithName: @"CupWarningException" reason: @"The level is >= 50" userInfo: nil ]; @throw e; }else if(level < 0){ NSException *e = [NSException exceptionWithName: @"NSException" reason: @"The level is < 0" userInfo: nil ]; @throw e; } NSLog(@"setLevel out : %d", l);}-(void) fill{ [self setLevel: level + 10];}-(void) empty{ [self setLevel: level - 10];}-(void) print{ NSLog(@"Cup level is :%i\n", level);} #include 
           
            int main(){ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; Cup *cup = [[Cup alloc] init]; int i; for(i = 0; i < 4; i++){ [cup fill]; [cup print]; } for(i = 0; i < 7; i++){ @try{ [cup fill]; }@catch(CupWarningException *e){ NSLog(@"e name:%s", [[e name] cString]); }@catch(CupOverflowException *e){ NSLog(@"e name:%s", [[e name] cString]); }@finally{ // 保证这里会执行 [cup print]; } } @try{ [cup setLevel: -1];#if 1 }@catch (NSException *e){ NSLog(@"%s:%s\n", [[e name] cString], [[e reason] cString]); }#else }@catch (id e){ // 这里可以直接用id NSLog(@"?????%s:%s\n", [[e name] cString], [[e reason] cString]); }#endif [cup release]; [pool release]; return 0;}#endif/* 输出结果2012-06-21 02:02:06.691 main[7510] setLevel in : 02012-06-21 02:02:06.692 main[7510] setLevel out : 02012-06-21 02:02:06.692 main[7510] setLevel in : 102012-06-21 02:02:06.692 main[7510] setLevel out : 102012-06-21 02:02:06.692 main[7510] Cup level is :102012-06-21 02:02:06.692 main[7510] setLevel in : 202012-06-21 02:02:06.692 main[7510] setLevel out : 202012-06-21 02:02:06.692 main[7510] Cup level is :202012-06-21 02:02:06.692 main[7510] setLevel in : 302012-06-21 02:02:06.692 main[7510] setLevel out : 302012-06-21 02:02:06.692 main[7510] Cup level is :302012-06-21 02:02:06.692 main[7510] setLevel in : 402012-06-21 02:02:06.692 main[7510] setLevel out : 402012-06-21 02:02:06.692 main[7510] Cup level is :402012-06-21 02:02:06.692 main[7510] setLevel in : 502012-06-21 02:02:06.692 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :502012-06-21 02:02:06.693 main[7510] setLevel in : 602012-06-21 02:02:06.693 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :602012-06-21 02:02:06.693 main[7510] setLevel in : 702012-06-21 02:02:06.693 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :702012-06-21 02:02:06.693 main[7510] setLevel in : 802012-06-21 02:02:06.693 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :802012-06-21 02:02:06.693 main[7510] setLevel in : 902012-06-21 02:02:06.693 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :902012-06-21 02:02:06.693 main[7510] setLevel in : 1002012-06-21 02:02:06.693 main[7510] e name:CupWarningException2012-06-21 02:02:06.693 main[7510] Cup level is :1002012-06-21 02:02:06.693 main[7510] setLevel in : 1102012-06-21 02:02:06.693 main[7510] e name:CupOverflowException2012-06-21 02:02:06.693 main[7510] Cup level is :1102012-06-21 02:02:06.693 main[7510] setLevel in : -12012-06-21 02:02:06.693 main[7510] NSException:The level is < 0 */// 继承 （Inheritance）#if 0#import 
            
             #import 
             
               Rectangle: NSObject{ int width; int height;}#if 1-(Rectangle*) initWithWidth: (int) w height: (int) h;#else-(id) initWithWidth: (int) w height: (int) h;#endif-(void) setWidth: (int) w;-(void) setHeight: (int) h;-(void) setWidth: (int) w height: (int) h;-(int) widht;-(int) height;-(void) print; @implementation Rectangle#if 1-(Rectangle*) initWithWidth: (int) w height: (int) h{#else-(id) initWithWidth: (int) w height: (int) h{#endif self = [super init]; if(self){ [self setWidth:w height: h]; } return self;}-(void) setWidth: (int) w{ width = w;}-(void) setHeight: (int) h{ height = h;}-(void) setWidth: (int) w height: (int) h{ width = w; height = h;}-(int) widht{ return width;}-(int) height{ return height;}-(void) print{ NSLog(@"width = %i, height = %i", width, height);} // 子类 Square Square: Rectangle-(Square*) initWithSize: (int) s;-(void) setSize: (int) s;-(int) size; @implementation Square-(Square*) initWithSize: (int) s{ self = [super init]; if(self){ [self setSize: s]; } return self;}-(void) setSize: (int) s{ width = s; height = s;}-(int) size{ return width;}-(void) setWidth: (int) w{ [self setSize: w];}-(void) setHeight: (int) h{ [self setSize: h];} int main(){ Rectangle *rec = [[Rectangle alloc] initWithWidth: 10 height: 20];#if 1 Square *sq = [[Square alloc] initWithSize: 15];#else // 如果Rectangle中的initWithWidth申明为返回Rectangle,那么这行代码会有警告，但运行结果正确？？？ //main.m:376:5: warning: initialization from distinct Objective-C type [enabled by default] Square *sq = [[Square alloc] initWithWidth: 25 height: 25];#endif printf("Rectangle:"); [rec print]; printf("\n"); printf("Square: "); [sq print]; printf("\n"); //update [sq setWidth: 20]; printf("Square after change:"); [sq print]; printf("\n"); NSLog(@"%@", [rec class]);//返回rec的类名 //NSLog(@"%@", [sq isKindOfClass: [rec class]]);//段错误 if([sq isMemberOfClass:[Square class]] == YES){ printf("sq is member of square class\n"); } if([sq isMemberOfClass: [Rectangle class]] == YES){ printf("sq is member of rectangel class\n"); } if([sq isMemberOfClass:[NSObject class]] == YES){ printf("sq is member of NSObject class\n"); } if([sq isKindOfClass:[Square class]] == YES){ printf("sq is kind of square class\n"); } if([sq isKindOfClass: [Rectangle class]] == YES){ printf("sq is kind of rectangel class\n"); } if([sq isKindOfClass:[NSObject class]] == YES){ printf("sq is kind of NSObject class\n"); } //respondsToSelector //true if([sq respondsToSelector: @selector(setSize:)] == YES){ printf("sq responds to setSize: method\n"); } //false if([sq respondsToSelector: @selector(nonExistant)] == YES){ printf("sq responds to nonExistant method\n"); } //true if([Square respondsToSelector: @selector(alloc)] == YES){ printf("square class responds to alloc method\n"); } //instancesRespondToSelector //false if([Rectangle instancesRespondToSelector: @selector(setSize:)] == YES){ printf("rectangle instance responds to setSize: method\n"); } //true if([Square instancesRespondToSelector: @selector(setSize:)] == YES){ printf("square instance responds to setSize: method\n"); } [sq release]; [rec release]; return 0;}/* 结果如下，为什么NSLog打印的内容会比printf要快呢？？？？？？2012-06-21 02:37:30.160 main[8451] width = 10, height = 20Rectangle:2012-06-21 02:37:30.161 main[8451] width = 15, height = 15Square: 2012-06-21 02:37:30.161 main[8451] width = 20, height = 20Square after change:sq is member of square classsq is kind of square classsq is kind of rectangel classsq is kind of NSObject classsq responds to setSize: methodsquare class responds to alloc methodsquare instance responds to setSize: method */#endif/// Categories// 扩展类：可以在原类基础上扩展接口，不用继承的方法重写类// 重点是@implemention 跟 这两行：// 类名后加入了(Math)。// 同一个class只能有一个同名的category，其他的categories的加上不同的独一无二的名字。#if 0#import "Fraction.h" Fraction(Math)-(Fraction*) add: (Fraction*) f;-(Fraction*) mul: (Fraction*) f;//-(Fraction*) div: (Fraction*) f;//-(Fraction*) sub: (Fraction*) f; @implementation Fraction(Math)-(Fraction*) add: (Fraction*) f{ return [[Fraction alloc] initWithNumerator: numerator * [f denominator] + denominator * [f numerator] denominator: denominator * [f denominator] ]; }-(Fraction*) mul: (Fraction*) f{ return [[Fraction alloc] initWithNumerator: numerator * [f numerator] denominator: denominator * [f denominator] ];} int main(){ Fraction *frac1 = [[Fraction alloc] initWithNumerator: 1 denominator: 3]; Fraction *frac2 = [[Fraction alloc] initWithNumerator: 2 denominator: 5]; Fraction *frac3 = [frac1 mul: frac2]; [frac1 print]; printf(" * "); [frac2 print]; printf(" = "); [frac3 print]; printf(" \n"); [frac1 privateMethod]; [frac2 privateMethod]; [frac3 privateMethod]; [frac1 release]; [frac2 release]; [frac3 release]; return 0;}/*result1/3 * 2/5 = 2/15 */#endif//// Posing // 有点像categories， 但是又不太一样，它允许你扩充一个class， 并且全面性的扮演（pose）// 这个super class// 例如：有一个扩充NSArray的NSArrayChild，如果你让NSArrayChild扮演NSArray， 则在你的// 程序代码中，所有的NSArray都会自动替换为NSArrayChild。#if 0#import "Fraction.h" FractionB: Fraction-(void) print; @implementation FractionB-(void) print{ printf("(%i/%i)", numerator, denominator);} int main(){ Fraction *frac = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; //print it printf("The fraction is: "); [frac print]; printf("\n"); //./main: Uncaught exception NSInternalInconsistencyException, // reason: Class posing is not supported // 下面这句话在GNUstep中运行时会报错， [FractionB poseAsClass: [Fraction class]]; Fraction *frac2 = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; //print it printf("The fraction is: "); [frac2 print]; printf("\n"); //print it printf("The fraction is: "); [frac print]; printf("\n"); [frac2 release]; [frac release]; return 0;}#endif// Protocols// 和c++中的purely irtual class 纯虚函数相同#if 0#import 
              
                Fraction: NSObject
               
                { int numerator; int denominator;} @implementation Fraction //可以使用 id
                
                  var = frac;#endif// 内存管理// Retain和release是两个继承自NSObject的对象都会有的methods。// retain call 增加计数器值， 而release call减少它。// 使用[obj retainCount]取得计数器个数// 当retainCount个数达到0， 会dealloc自己#if 0#import 
                 
                   FractionEx:NSObject { int numerator; int denominator;} @implementation FractionEx-(void) dealloc{ printf("Deallocing fraction\n"); [super dealloc];} int main(){ FractionEx *frac1 = [[FractionEx alloc ] init]; FractionEx *frac2 = [[FractionEx alloc ] init]; printf("FractionEx 1 retain count: %i\n", [frac1 retainCount]);//1 printf("FractionEx 2 retain count: %i\n", [frac2 retainCount]);//1 printf("frac1 retain\n"); [frac1 retain];//2 printf("frac1 retain\n"); [frac1 retain];//3 printf("frac2 retain\n"); [frac2 retain];//2 printf("FractionEx 1 retain count: %i\n", [frac1 retainCount]); printf("FractionEx 2 retain count: %i\n", [frac2 retainCount]); printf("frac1 release\n"); [frac1 release];//2 printf("FractionEx 1 retain count: %i\n", [frac1 retainCount]); printf("FractionEx 2 retain count: %i\n", [frac2 retainCount]); printf("frac2 release\n"); [frac2 release];//1 printf("FractionEx 1 retain count: %i\n", [frac1 retainCount]); printf("FractionEx 2 retain count: %i\n", [frac2 retainCount]); printf("frac1 retain\n"); [frac1 release];//1 printf("frac1 retain\n"); [frac1 release];//0 printf("frac2 retain\n"); [frac2 release];//0 return 0;}#endif// Dealloc// 当你的对象包含其他对象时，就得在dealloc中自行释放。// objective-c的一个优点是可以传递nil，所以不需要经过一堆防错测试来释放一个对象#if 0#import 
                  
                   #import 
                   
                     AddressCard: NSObject{ NSString *first; NSString *last; NSString *email;}-(AddressCard*) initWithFirst:(NSString*) f last: (NSString*) l email: (NSString*) e;-(NSString*) first;-(NSString*) last;-(NSString*) email;-(void) setFirst:(NSString*) f;-(void) setLast:(NSString*) l;-(void) setEmail:(NSString*) e;-(void) setFirst:(NSString*) f last:(NSString*) l email:(NSString*) e;-(void) setFirst:(NSString*) f last:(NSString*) l;-(void) print; @implementation AddressCard-(AddressCard*) initWithFirst:(NSString*) f last: (NSString*) l email: (NSString*) e{ self = [super init]; if(self){ [self setFirst:f last: l email: e]; }}-(NSString*) first{ return first;}-(NSString*) last{ return last;}-(NSString*) email{ return email;}-(void) setFirst:(NSString*) f{ [f retain];//这里去掉会出现段错误 [first release]; first = f;}-(void) setLast:(NSString*) l{ [l retain]; [last release]; last = l;}-(void) setEmail:(NSString*) e{ [e retain]; [email release]; email = e;}-(void) setFirst:(NSString*) f last:(NSString*) l email:(NSString*) e{ [self setFirst: f]; [self setLast: l]; [self setEmail: e];}-(void) setFirst:(NSString*) f last:(NSString*) l{ [self setFirst: f]; [self setLast: l]; }-(void) print{ printf("%s %s <%s>", [first cString], [last cString], [email cString]); printf("\nclass first retaincount:%i", [first retainCount]); printf("\nclass last retaincount:%i", [last retainCount]); printf("\nclass email retaincount:%i", [email retainCount]);}-(void) dealloc{ [first release]; [last release]; [email release]; [super dealloc];} int main(){ NSString *first = [[NSString alloc] initWithCString: "Zhao"]; NSString *last = [[NSString alloc] initWithCString: "Kun"]; NSString *email = [[NSString alloc] initWithCString: "youning@qq.com"]; AddressCard *zhao = [[AddressCard alloc] initWithFirst: first last: last email: email ]; [first release]; [last release]; [email release]; printf("zhao first Retain count: %i\n", [[zhao first] retainCount]); printf("zhao last Retain count: %i\n", [[zhao last] retainCount]); printf("zhao email Retain count: %i\n", [[zhao email] retainCount]); [zhao print]; printf("\n"); [zhao release]; return 0;}/*zhao first Retain count: 1zhao last Retain count: 1zhao email Retain count: 12012-06-22 15:03:31.059 main[4257] autorelease called without pool for object (0x9195a10) of class GSAutoreleasedMemory in thread 
                    
                     2012-06-22 15:03:31.060 main[4257] autorelease called without pool for object (0x9196068) of class GSAutoreleasedMemory in thread 
                     
                      2012-06-22 15:03:31.060 main[4257] autorelease called without pool for object (0x9195848) of class GSAutoreleasedMemory in thread 
                      
                       Zhao Kun 
                       
                        class first retaincount:1class last retaincount:1class email retaincount:1 */#endif//// Autorelease pool// 在objective-c有两种管理内存的方法：// 1.retain 和 release// 2.retain 和release/autorelease// 对于每个retain， 一定对应一个release或一个autorelease#if 1#import 
                        
                         #import 
                         
                          #if 0int main(){ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSString *str1 = @"constant string"; NSString *str2 = [NSString stringWithString: @"string managed by the pool"]; NSString *str3 = [[NSString alloc] initWithString: @"self managed string"]; printf("%s retain count: %x\n", [str1 cString], [str1 retainCount]); printf("%s retain count: %x\n", [str2 cString], [str2 retainCount]); printf("%s retain count: %x\n", [str3 cString], [str3 retainCount]); [str3 release]; [pool release];}/*constant string retain count: 343bstring managed by the pool retain count: 1self managed string retain count: 1执行这个程序会发现几个问题：1.str1的retainCount为343b2.虽然只有release str3， 但是整个程序却还是处于完美的内存管理下，原因是第一个常数字符串已经自动加到autorelease pool里了。字符串是由stringWithString产生的， 这个接口会产生一个NSString class类型的字符串，并自动加进autorelease pool中。*/#endif#if 0// 对任何retain而言，一定要调用release或autorelease， 对象的retainCount从1起跳，然后我在// 上面调用1次autorelease，表示1-1=0， 当autorelease pool被释放时， 它会计算所有对象上的// autorealease调用次数， 并调用相同次数的[obj release];#import "Fraction.h" Fraction(Ex)+(Fraction*) fractionWithNumerator: (int) n denominator: (int) d; @implementation Fraction(Ex)+(Fraction*) fractionWithNumerator: (int) n denominator: (int) d{ Fraction *ret = [[Fraction alloc] initWithNumerator: n denominator: d]; [ret autorelease]; return ret;} int main(){ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; Fraction *frac1 = [Fraction fractionWithNumerator:2 denominator: 5]; Fraction *frac2 = [Fraction fractionWithNumerator: 1 denominator: 3]; printf("Fraction 1: "); [frac1 print]; printf("\n"); printf("Fraction 2: "); [frac2 print]; printf("\n"); //下面这句话会出现段错误 //[frac1 release]; [pool release]; return 0; }#endif#endif//// NSArray// 数组有两种，NSArray和NSMutableArray，// NSArray不能改变长度，NSMutableArray可以改变// NSEnumerator很想java的列举系统，#if 0#import 
                          
                           #import 
                           
                            #import 
                            
                             #import 
                             
                              void print(NSArray *array){ NSEnumerator *enumerator = [array objectEnumerator]; id obj; while(obj = [enumerator nextObject]){ printf("%s\n", [[obj description] cString]); }}int main(){ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSArray *arr = [[NSArray alloc] initWithObjects: @"Me", @"Myself", @"I", nil]; NSMutableArray *mutable = [[NSMutableArray alloc] init]; printf("----static array\n"); print(arr); // add stuff [mutable addObject: @"One"]; [mutable addObject: @"Two"]; [mutable addObjectsFromArray: arr]; [mutable addObject: @"Three"]; printf("----mutable array\n"); print(mutable); //sort printf("----sorted mutable array\n"); [mutable sortUsingSelector: @selector(caseInsensitiveCompare:)]; print(mutable); //free [arr release]; [mutable release]; [pool release]; return 0;}/*----static arrayMeMyselfI----mutable arrayOneTwoMeMyselfIThree----sorted mutable arrayIMeMyselfOneThreeTwo*/#endif//// NSDictionary#if 1#import 
                              
                               #import 
                               
                                #import 
                                
                                 #import 
                                 
                                  #import 
                                  
                                   void print(NSDictionary *map){ NSEnumerator *enumerator = [map keyEnumerator]; id key; while((key = [enumerator nextObject]) != nil){ printf("%s => %s\n", [[key description] cString] , [[[map objectForKey: key] description] cString]); }}int main(){ NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSDictionary * dict = [[NSDictionary alloc] initWithObjectsAndKeys: @"one", [NSNumber numberWithInt: 1], @"two", [NSNumber numberWithInt: 2], @"three", [NSNumber numberWithInt: 3], nil]; NSMutableDictionary *mutable = [[NSMutableDictionary alloc] init]; printf("----static dictionary\n"); print(dict); //add object [mutable setObject: @"Tom" forKey: @"tom@jones.com"]; [mutable setObject: @"Bob" forKey: @"bob@dole.com"]; printf("----mutable dictionary\n"); print(mutable); //free [dict release]; [mutable release]; [pool release];}/*----static dictionary3 => three1 => one2 => two----mutable dictionarybob@dole.com => Bobtom@jones.com => Tom */#endif