Objective--C之《文件操作》练习代码

#import <Foundation/Foundation.h>

@interface Baby : NSObject <NSCoding>
//声明实例变量
@property (nonatomic, assign) int age;
@property (nonatomic, retain) NSString *name;
@property (nonatomic, assign) double score;

- (id)initWithAge:(int)a andName:(NSString *)n andScore:(double)s;

- (void)print;

@end

#import "Baby.h"

@implementation Baby

- (id)initWithAge:(int)a andName:(NSString *)n andScore:(double)s
{
    if (self = [super init])
    {
        _age = a;
        self.name = n;
        _score = s;
    }
    return self;
}
//归档（将数据存入文件）
- (void)encodeWithCoder:(NSCoder *)aCoder//往文件中写入实例变量
{
    [aCoder encodeObject:[NSNumber numberWithInt:_age] forKey:@"1"];
    [aCoder encodeObject:_name forKey:@"2"];
    [aCoder encodeObject:[NSNumber numberWithDouble:_score] forKey:@"3"];
}
//解档并初始化（读取文件中的数据）
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder//从文件中读取实例变量为当前对象赋值
{
    if (self = [super init])
    {
        _age = [[aDecoder decodeObjectForKey:@"1"] intValue];
        self.name = [aDecoder decodeObjectForKey:@"2"];
        _score = [[aDecoder decodeObjectForKey:@"3"] doubleValue];
    }
    return self;
}


- (void)print
{
    NSLog(@"Age = %d, Name = %@, Score = %.2lf", _age, self.name, _score);
}

- (void)dealloc
{
    [_name release];
    [super dealloc];
}

@end

#import <Foundation/Foundation.h>
#import "Baby.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool
    {
#pragma mark - 管理文件和目录
        //创建一个NSFileManager对象
        NSFileManager *fm = [NSFileManager defaultManager];
        NSError *err = nil;
        NSDictionary *attr = [fm attributesOfItemAtPath:@"filePath" error:&err];
        //从属性字典里取出一个特定的属性：文件大小
        int filesize = [[attr objectForKey:NSFileSize] intValue];
        NSData *data = [fm contentsAtPath:@"/Users/hskj/AddressCard.txt"];
//        AddressCard *card1 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
//        NSLog(@"card1 %@", card1);
        [fm createFileAtPath:@"/Users/hskj/AddressCard.txt" contents:data attributes:nil];
        //removeItemAtPath:error:删除指定的文件， 如：
        [fm removeItemAtPath:@"/Users/hskj/AddressCard.txt" error:&err];
        //fileExistsAtPath:判断指定文件是否存在，如
        [fm fileExistsAtPath:@"/Users/hskj/AddressCard.txt"];
        //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：
        [fm copyItemAtPath:@"/Users/hskj/AddressCard1.txt" toPath:@"/Users/hskj/AddressCard2.txt" error:&err];
        
#pragma mark - NSCoding协议例题
        Baby *b = [[Baby alloc] initWithAge:23 andName:@"songlei" andScore:99   ];
        [b print];
        
        NSString *pathDirectory = [NSString stringWithFormat:@"%@/Users/hskj/songlei.txt", NSHomeDirectory()];
        //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）
        [NSKeyedArchiver archiveRootObject:b toFile:pathDirectory];
        //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）
        Baby *b1 = [NSKeyedUnarchiver unarchiveObjectWithFile:pathDirectory];
        [b1 print];
    }
    return 0;
}

 /*
 如果把自己定义的类所创建的对象直接写入文件的步骤：
 1) 自定义类遵循NSCoding协议，实现NSCoding协议中的两个方法：
    encodeWithCoder:往文件中写入实例变量
    initWithCoder:从文件中读取实例变量为当前对象赋值
 2) 如果把对象写入文件：调用NSKeyedArchiver中的archiveRootObject:toFile:
 3) 如果把对象从文件中读取出来：调用NSKeyedUnarchiver中的 unarchiveObjectWithFile:
 */

#import <Foundation/Foundation.h>

@interface Person : NSObject <NSCoding>

//声明实例变量
@property (nonatomic, strong) NSString *name;
@property (nonatomic, assign) int age;

- (id)init;

@end

#import "Person.h"

@implementation Person

- (id)init
{
    if (self = [super init])
    {
        self.name = @"songlei";
        _age = 18;
    }
    return self;
}
//归档（将数据存入文件）
- (void)encodeWithCoder:(NSCoder *)aCoder//往文件中写入实例变量
{
    [aCoder encodeObject:_name forKey:@"0"];
    [aCoder encodeObject:[NSNumber numberWithInt:_age] forKey:@"1"];
}
//解档并初始化（读取文件中的数据）
- (id)initWithCoder:(NSCoder *)aDecoder//从文件中读取实例变量为当前对象赋值
{
    if (self = [super init])
    {
        self.name = [aDecoder decodeObjectForKey:@"0"];
        _age = [[aDecoder decodeObjectForKey:@"1"] intValue];
    }
    return self;
}

@end

#import <Foundation/Foundation.h>
#import "Person.h"

int main(int argc, const char * argv[])
{
    @autoreleasepool
    {
//        //创建一个NSFileManager对象
//        NSString *pathStr = [[NSFileManager defaultManager] currentDirectoryPath];//当前目录路径（也叫相对路径名）
//        NSString *realFile = [pathStr stringByAppendingString:@"/huashan.txt"];
//        [[NSFileManager defaultManager] createFileAtPath:realFile contents:nil attributes:nil];
//        NSLog(@"%@", pathStr);
        NSString *str2 = @"/Users/hskj/Documents/mazi.txt";
        [[NSFileManager defaultManager] createFileAtPath:str2 contents:nil attributes:nil];
//        NSString *str2 = [NSString stringWithFormat:@"%@/Documents/xiaoming.txt", NSHomeDirectory()];
//        [[NSFileManager defaultManager] createFileAtPath:str2 contents:nil attributes:nil];
        
        Person *p = [[Person alloc] init];
        NSString *str1 = [NSString stringWithFormat:@"%@/Documents/xiaoming.txt", NSHomeDirectory()];
        
        [NSKeyedArchiver archiveRootObject:p toFile:str1];
        
        Person *p1 = [NSKeyedUnarchiver unarchiveObjectWithFile:str1];
        NSLog(@"name: %@, age = %d", p1.name, p1.age);
        NSData *data = [NSData dataWithContentsOfFile:str1];
        NSLog(@"%@", data);
        Person *p3 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
        NSLog(@"%@", p3.name);
        
        NSError *err = nil;
        NSDictionary *attr = [[NSFileManager defaultManager] attributesOfItemAtPath:str1 error:&err];
        NSLog(@"%@", attr);
        
        [[NSFileManager defaultManager] removeItemAtPath:str1 error:nil];
        [[NSFileManager defaultManager] removeItemAtPath:str2 error:nil];
        

    }
    
    return 0;
}