Qustion:（MRC下）
1、定义一个Computer类
实例变量：float width; NSString *name;
方法：一个带两个参数的初始化函数；print()函数；dealloc()函数；
2、定义一个Person类
实例变量：NSString *name; Computer *c; int age;
方法：一个带三个参数的初始化函数；print()函数；dealloc()函数；
要求：用该类创建出来的对象能实现copy和存入文件。
3、主函数要求：
a)分别创建Computer类的对象cc和Person类对象pp;并输出对象信息。
b)利用copy函数创建Person类对象p1; 并输出对象信息
c)把pp存入文件hello.txt中，文件目录为Documents目录。
d)从文件hello.txt中读取对象p2, 并输出对象信息。
e)不能出现内存泄漏和多次删除。
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Source code:
1 #import <Foundation/Foundation.h> 2 3 @interface Computer : NSObject <NSCoding> 4 5 @property (nonatomic, assign) float width; 6 @property (nonatomic, retain) NSString *name; 7 8 - (id)initWithWidth:(float)w andName:(NSString *)n; 9 10 - (void)print; 11 12 @end 13 14 #import "Computer.h" 15 16 @implementation Computer 17 18 - (id)initWithWidth:(float)w andName:(NSString *)n 19 { 20 if (self = [super init]) 21 { 22 _width = w; 23 self.name = n; 24 } 25 return self; 26 } 27 28 - (void)print 29 { 30 NSLog(@"Width = %f, Name = %@", _width, _name); 31 } 32 //编码 33 - (void)encodeWithCoder:(NSCoder *)aCoder 34 { 35 [aCoder encodeObject:[NSNumber numberWithFloat:_width] forKey:@"1"]; 36 [aCoder encodeObject:_name forKey:@"2"]; 37 } 38 //解码 39 - (id)initWithCoder:(NSCoder *)aDecoder 40 { 41 if (self = [super init]) 42 { 43 _width = [[aDecoder decodeObjectForKey:@"1"] floatValue]; 44 self.name = [aDecoder decodeObjectForKey:@"2"]; 45 } 46 return self; 47 } 48 49 - (void)dealloc 50 { 51 self.name = nil; 52 [super dealloc]; 53 } 54 55 @end 56 57 #import <Foundation/Foundation.h> 58 59 @class Computer; 60 @interface Person : NSObject <NSCoding, NSCopying> 61 62 @property (nonatomic, assign) int age; 63 @property (nonatomic, retain) NSString *name; 64 @property (nonatomic, retain) Computer *c; 65 66 - (id)initWithAge:(int)a andName:(NSString *)n andComputer:(Computer *)cc; 67 68 - (void)print; 69 70 @end 71 72 #import "Person.h" 73 #import "Computer.h" 74 75 @implementation Person 76 77 - (id)copyWithZone:(NSZone *)zone 78 { 79 Person *p = [[Person allocWithZone:zone] initWithAge:_age andName:_name andComputer:_c]; 80 return p; 81 } 82 83 - (void)encodeWithCoder:(NSCoder *)aCoder 84 { 85 [aCoder encodeObject:_name forKey:@"1"]; 86 [aCoder encodeObject:_c forKey:@"2"]; 87 [aCoder encodeObject:[NSNumber numberWithInt:_age] forKey:@"3"]; 88 } 89 90 - (id)initWithCoder:(NSCoder *)aDecoder 91 { 92 if (self = [super init]) 93 { 94 self.name = [aDecoder decodeObjectForKey:@"1"]; 95 self.c = [aDecoder decodeObjectForKey:@"2"]; 96 _age = [[aDecoder decodeObjectForKey:@"3"] intValue]; 97 } 98 return self; 99 } 100 101 - (id)initWithAge:(int)a andName:(NSString *)n andComputer:(Computer *)cc 102 { 103 if (self = [super init]) 104 { 105 _age = a; 106 self.name = n; 107 self.c = cc; 108 } 109 return self; 110 } 111 112 - (void)print 113 { 114 NSLog(@"Age = %d, Name = %@, Computer = %@", _age, _name, _c); 115 } 116 117 - (void)dealloc 118 { 119 self.name = nil; 120 self.c = nil; 121 122 [super dealloc]; 123 } 124 125 @end 126 127 #import <Foundation/Foundation.h> 128 #import "Computer.h" 129 #import "Person.h" 130 131 int main(int argc, const char * argv[]) { 132 @autoreleasepool { 133 Computer *c = [[Computer alloc] initWithWidth:20.5 andName:@"Apple"]; 134 [c print]; 135 136 Person *p = [[Person alloc] initWithAge:20 andName:@"xiaoming" andComputer:c]; 137 [p print]; 138 139 Person *p1 = [p copy]; 140 [p1 print]; 141 142 NSString *path = @"/Users/hskj/Documents/hello.txt"; 143 [NSKeyedArchiver archiveRootObject:p toFile:path]; 144 Person *p2 = [NSKeyedUnarchiver unarchiveObjectWithFile:path]; 145 [p2 print]; 146 147 [p1 release]; 148 [p release]; 149 [c release]; 150 } 151 return 0; 152 }