Objective--C之文件操作练习代码(随便写的，有错误)

 1 #import <Foundation/Foundation.h>
 2
 3 @interface Baby : NSObject <NSCoding>
 4 //声明实例变量
 5 @property (nonatomic, assign) int age;
 6 @property (nonatomic, retain) NSString *name;
 7 @property (nonatomic, assign) double score;
 8
 9 - (id)initWithAge:(int)a andName:(NSString *)n andScore:(double)s;
10
11 - (void)print;
12
13 @end
14
15 #import "Baby.h"
16
17 @implementation Baby
18
19 - (id)initWithAge:(int)a andName:(NSString *)n andScore:(double)s
20 {
21     if (self = [super init])
22     {
23         _age = a;
24         self.name = n;
25         _score = s;
26     }
27     return self;
28 }
29 //归档（将数据存入文件）
30 - (void)encodeWithCoder:(NSCoder *)aCoder//往文件中写入实例变量
31 {
32     [aCoder encodeObject:[NSNumber numberWithInt:_age] forKey:@"1"];
33     [aCoder encodeObject:_name forKey:@"2"];
34     [aCoder encodeObject:[NSNumber numberWithDouble:_score] forKey:@"3"];
35 }
36 //解档并初始化（读取文件中的数据）
37 - (nullable instancetype)initWithCoder:(NSCoder *)aDecoder//从文件中读取实例变量为当前对象赋值
38 {
39     if (self = [super init])
40     {
41         _age = [[aDecoder decodeObjectForKey:@"1"] intValue];
42         self.name = [aDecoder decodeObjectForKey:@"2"];
43         _score = [[aDecoder decodeObjectForKey:@"3"] doubleValue];
44     }
45     return self;
46 }
47
48
49 - (void)print
50 {
51     NSLog(@"Age = %d, Name = %@, Score = %.2lf", _age, self.name, _score);
52 }
53
54 - (void)dealloc
55 {
56     [_name release];
57     [super dealloc];
58 }
59
60 @end
61
62 #import <Foundation/Foundation.h>
63 #import "Baby.h"
64 int main(int argc, const char * argv[]) {
65     @autoreleasepool
66     {
67 #pragma mark - 管理文件和目录
68         //创建一个NSFileManager对象
69         NSFileManager *fm = [NSFileManager defaultManager];
70         NSError *err = nil;
71         NSDictionary *attr = [fm attributesOfItemAtPath:@"filePath" error:&err];
72         //从属性字典里取出一个特定的属性：文件大小
73         int filesize = [[attr objectForKey:NSFileSize] intValue];
74         NSData *data = [fm contentsAtPath:@"/Users/hskj/AddressCard.txt"];
75 //        AddressCard *card1 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
76 //        NSLog(@"card1 %@", card1);
77         [fm createFileAtPath:@"/Users/hskj/AddressCard.txt" contents:data attributes:nil];
78         //removeItemAtPath:error:删除指定的文件， 如：
79         [fm removeItemAtPath:@"/Users/hskj/AddressCard.txt" error:&err];
80         //fileExistsAtPath:判断指定文件是否存在，如
81         [fm fileExistsAtPath:@"/Users/hskj/AddressCard.txt"];
82         //copyItemAtPath:toPath:error:  把第一个参数中指定的文件内容拷贝到toPath指定的文件中，如：
83         [fm copyItemAtPath:@"/Users/hskj/AddressCard1.txt" toPath:@"/Users/hskj/AddressCard2.txt" error:&err];
84
85 #pragma mark - NSCoding协议例题
86         Baby *b = [[Baby alloc] initWithAge:23 andName:@"songlei" andScore:99   ];
87         [b print];
88
89         NSString *pathDirectory = [NSString stringWithFormat:@"%@/Users/hskj/songlei.txt", NSHomeDirectory()];
90         //归档类：把对象b归档到此文件中去（此时系统会自动调用协议中的归档方法）
91         [NSKeyedArchiver archiveRootObject:b toFile:pathDirectory];
92         //解档类：把对象b1从此文件中去取出（此时系统会自动调用协议中的接档方法）
93         Baby *b1 = [NSKeyedUnarchiver unarchiveObjectWithFile:pathDirectory];
94         [b1 print];
95     }
96     return 0;
97 }