【iOS】数据持久化

1
NSString* path = [[NSBundle mainBundle] bundlePath];
2
NSLog(@"%@", path);

1
NSString* path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject;
2
NSLog(@"%@", path);

1
//获取Library：NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).lastObject
2
NSString* path = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject;
3
NSLog(@"%@", path);

1
NSString* path = NSTemporaryDirectory();
2
NSLog(@"%@", path);

1
@interface Person : NSObject <NSSecureCoding>
2

3
@property (nonatomic, copy)NSString* name;
4
@property (nonatomic, assign)int age;
5
@property (nonatomic, assign)double weight;
6

7
@end
8

9
@implementation Person
10

11
//NSCoder是一个抽象类
12
//归档的协议方法
13
//将归档对象序列化
14
- (void)encodeWithCoder:(NSCoder *)coder {
15
    [coder encodeObject: self.name forKey: @"name"];
16
    [coder encodeInt: self.age forKey: @"age"];
17
    [coder encodeDouble: self.weight forKey: @"weight"];
18
}
19

20
//解档的协议方法
21
//将解档对象反序列化
22
- (instancetype)initWithCoder:(NSCoder *)coder {
23
    self = [super init];
24
    if (self) {
25
        self.name = [coder decodeObjectForKey: @"name"];
26
        self.age = [coder decodeIntForKey: @"age"];
27
        self.weight = [coder decodeDoubleForKey: @"weight"];
28
    }
29

30
    return self;
31
}
32

33
@end
34

35
//NSSecureCoding的协议方法
36
+ (BOOL)supportsSecureCoding {
37
    return YES;
38
}

1
Person* person = [[Person alloc] init];
2
        person.name = @"XY";
3
        person.age = 20;
4
        person.weight = 125.0;
5

6
        //归档成二进制数据流
7
        NSError* error;
8
        NSData* data1 = [NSKeyedArchiver archivedDataWithRootObject: person requiringSecureCoding: YES error: &error];
9
        if (error) {
10
            NSLog(@"归档错误：%@", error);
11
            return 0;
12
        }
13
        //写入指定路径（一般写入到沙盒，这里方便演示存到一个新的文件夹）
14
        [data1 writeToFile: @"/Users/jakey/Desktop/CS/Xcode/NSKeyedArchiverTest/test.archiver" atomically: YES];

1
//解档此二进制数据
2
        error = nil;
3
        NSData* data2 = [NSData dataWithContentsOfFile: @"/Users/jakey/Desktop/CS/Xcode/NSKeyedArchiverTest/test.archiver"];
4
        Person* unarchiverPerson = (Person *)[NSKeyedUnarchiver unarchivedObjectOfClass: [Person class] fromData: data2 error: &error];
5
        if (error) {
6
            NSLog(@"解档错误：%@", error);
7
        }
8
        NSLog(@"unarchiverPerson：%@", unarchiverPerson);
9
### 多个对象解档归档
10

11

12
1、初始化待归档对象并归档
13

14

15
```objective-c
16
Person* person1 = [[Person alloc] init];
17
person1.name = @"XY";
18
person1.age = 20;
19
person1.weight = 125.0;
20
Dog* dog1 = [[Dog alloc] init];
21
dog1.name = @"Bruce";
22
person1.dog = dog1;
23

24
Person* person2 = [[Person alloc] init];
25
person2.name = @"Jacky";
26
person2.age = 21;
27
person2.weight = 130.0;
28
Dog* dog2 = [[Dog alloc] init];
29
dog2.name = @"Oudy";
30
person2.dog = dog2;
31

32
//创建归档对象
33
NSKeyedArchiver* archiver = [[NSKeyedArchiver alloc] initRequiringSecureCoding: NO];
34

35
//进行归档（编码）操作
36
[archiver encodeObject: person1 forKey: @"personOne"];
37
[archiver encodeObject: person2 forKey: @"personTwo"];
38

39
//将归档（序列化）后的数据写入指定文件中
40
[archiver.encodedData writeToFile: @"/Users/jakey/Desktop/CS/Xcode/NSKeyedArchiverTest/test.archiver" atomically: YES];
41

42
//结束归档
43
[archiver finishEncoding];

1
//解档
2
NSData* data = [NSData dataWithContentsOfFile: @"/Users/jakey/Desktop/CS/Xcode/NSKeyedArchiverTest/test.archiver"];
3
NSKeyedUnarchiver* unarchiver = [[NSKeyedUnarchiver alloc] initForReadingFromData: data error: nil];
4
unarchiver.requiresSecureCoding = NO;
5

6
Person* unchiverPerson1 = [unarchiver decodeObjectForKey: @"personOne"];
7
NSLog(@"%@ %d %lf %@", unchiverPerson1.name, unchiverPerson1.age, unchiverPerson1.weight, unchiverPerson1.dog.name);
8
Person* unchiverPerson2 = [unarchiver decodeObjectForKey: @"personTwo"];
9
NSLog(@"%@ %d %lf %@", unchiverPerson2.name, unchiverPerson2.age, unchiverPerson2.weight, unchiverPerson2.dog.name);

1
下面的几种方式等价：
2

3

4
```objective-c
5
/* 1. 直接使用完整的SQL更新语句 */
6
[database executeUpdate:@"insert into mytable(num,name,sex) values(0,'liuting','m');"];
7

8
NSString *sql = @"insert into mytable(num,name,sex) values(?,?,?);";
9
/* 2. 使用不完整的SQL更新语句，里面含有待定字符串"?"，需要后面的参数进行替代 */
10
[database executeUpdate:sql,@0,@"liuting",@"m"];
11
/* 3. 使用不完整的SQL更新语句，里面含有待定字符串"?"，需要数组参数里面的参数进行替代 */
12
[database executeUpdate:sql
13
   withArgumentsInArray:@[@0,@"liuting",@"m"]];
14

15
/* 4. SQL语句字符串可以使用字符串格式化，这种我们应该比较熟悉 */
16
[database executeUpdateWithFormat:@"insert into mytable(num,name,sex) values(%d,%@,%@);",0,@"liuting","m"];

1
/* 执行查询SQL语句，返回FMResultSet查询结果 */
2
- (FMResultSet *)executeQuery:(NSString*)sql, ... ;
3
- (FMResultSet *)executeQueryWithFormat:(NSString*)format, ... ;
4
- (FMResultSet *)executeQuery:(NSString *)sql withArgumentsInArray:(NSArray *)arguments;

1
/* 获取下一个记录 */
2
- (BOOL)next;
3
/* 获取记录有多少列 */
4
- (int)columnCount;
5
/* 通过列名得到列序号，通过列序号得到列名 */
6
- (int)columnIndexForName:(NSString *)columnName;
7
- (NSString *)columnNameForIndex:(int)columnIdx;
8
/* 获取存储的整形值 */
9
- (int)intForColumn:(NSString *)columnName;
10
- (int)intForColumnIndex:(int)columnIdx;
11
/* 获取存储的长整形值 */
12
- (long)longForColumn:(NSString *)columnName;
13
- (long)longForColumnIndex:(int)columnIdx;
14
/* 获取存储的布尔值 */
15
- (BOOL)boolForColumn:(NSString *)columnName;
16
- (BOOL)boolForColumnIndex:(int)columnIdx;
17
/* 获取存储的浮点值 */
18
- (double)doubleForColumn:(NSString *)columnName;
19
- (double)doubleForColumnIndex:(int)columnIdx;
20
/* 获取存储的字符串 */
21
- (NSString *)stringForColumn:(NSString *)columnName;
22
- (NSString *)stringForColumnIndex:(int)columnIdx;
23
/* 获取存储的日期数据 */
24
- (NSDate *)dateForColumn:(NSString *)columnName;
25
- (NSDate *)dateForColumnIndex:(int)columnIdx;
26
/* 获取存储的二进制数据 */
27
- (NSData *)dataForColumn:(NSString *)columnName;
28
- (NSData *)dataForColumnIndex:(int)columnIdx;
29
/* 获取存储的UTF8格式的C语言字符串 */
30
- (const unsigned cahr *)UTF8StringForColumnName:(NSString *)columnName;
31
- (const unsigned cahr *)UTF8StringForColumnIndex:(int)columnIdx;
32
/* 获取存储的对象，只能是NSNumber、NSString、NSData、NSNull */
33
- (id)objectForColumnName:(NSString *)columnName;
34
- (id)objectForColumnIndex:(int)columnIdx;