沙盒存储——plist
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属性列表是一种XML格式的文件，拓展名为plist。如果对象是NSString、NSDictionary、NSArray、NSData、NSNumber等类型，就可以使用writeToFile:atomically:方法直接将对象写到属性列表文件中
如果是其他类型的的对象，需要使用plist储存，需要转类型：
例如：//转化Data
NSData * imageData = UIImagePNGRepresentation(getImage);
存：
//获取路径
// NSSearchPath寻找路径
// ForDirectories要找的文件夹
// InDomains在哪个地方找
// NSDocumentDirectory Documents
NSString *docPath=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
//拼接路径
NSString *filePath = [docPath stringByAppendingPathComponent:@"xxxx.plist"];
//创建字典
NSDictionary *dict =@{@"name":@"laoma",@"age":@"18"};
// 存储字典
[dict writeToFile:filePath atomically:YES];
取：
//获取doc路径
NSString *docPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
//拼接plist路径
NSString *filePath = [docPath stringByAppendingPathComponent:@"xxxx.plist"];
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:filePath];
NSLog(@"%@",dict[@"name"]);
字符串存取
- (IBAction)save:(id)sender {
//获取docpath
NSString *docpath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
//拼接路径
NSString *filepath = [docpath stringByAppendingPathComponent:@"x.plist"];
NSString *str =@“hello word"
;
[str writeToFile:filepath atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
- (IBAction)read:(id)sender {
//获取docpath
NSString *docpath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
//拼接路径
NSString *filepath = [docpath stringByAppendingPathComponent:@"x.plist"];
// 获取字符串
NSString *str = [NSString stringWithContentsOfFile:filepath encoding:NSUTF8StringEncoding error:nil];
NSLog(@"%@",str);
}
沙盒储存——归档解档
#import<Foundation/Foundation.h>
@interface Person :NSObject<NSCoding>
@property(nonatomic,copy)NSString *name;
@property(nonatomic,assign)NSInteger age;
@end
#import"Person.h"
@implementationPerson
//告诉系统归档哪些属性
- (void)encodeWithCoder:(NSCoder *)aCoder {
[aCoder encodeObject:_name forKey:@"name"];
[aCoder encodeInteger:_age forKey:@"age"];
}
//告诉系统解档哪些属性,如何解档
- (instancetype)initWithCoder:(NSCoder *)aDecoder {
if(self= [super init]) {
_name= [aDecoder decodeObjectForKey:@"name"];
_age= [aDecoder decodeIntegerForKey:@"age"];
}
return self;
}
@end
#import "ViewController.h"
#import "Person.h"
@interface ViewController()
@end
@implementation ViewController
//归档
- (IBAction)save:(id)sender {
//创建对象
Personn*p = [[Person alloc]init];
p.name=@"zhangsan";
p.age=18;
// docpath
NSString *docPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
// 拼接路径
NSString *fliePath = [docPath stringByAppendingPathComponent:@"person.data"];
//归档
[NSKeyedArchiver archiveRootObject:p toFile:fliePath];
}
//解档
- (IBAction)read:(id)sender {
// docpath
NSString *docPath =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)[0];
// 拼接路径
NSString *fliePath = [docPath stringByAppendingPathComponent:@"person.data"];
//解档
Person *p = [NSKeyedUnarchiver unarchiveObjectWithFile:fliePath];
NSLog(@"%@",p.name);
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.}
- (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.}
@end
沙盒存储——偏好设置userDefaults
保存设置
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:@"itcast" forKey:@"username"];
[defaults setFloat:18.0f forKey:@"text_size"];
[defaults setBool:YES forKey:@"auto_login"];
读取上次保存的设置
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *username = [defaults stringForKey:@"username"];
float textSize = [defaults floatForKey:@"text_size"];
BOOL autoLogin = [defaults boolForKey:@"auto_login"];
注意：UserDefaults设置数据时，不是立即写入，而是根据时间戳定时地把缓存中的数据写入本地磁盘。所以调用了set方法之后数据有可能还没有写入磁盘应用程序就终止了。出现以上问题，可以通过调用synchornize方法强制写入
[defaults synchornize];