iOS Plist,NSUserDefault,归档总结

最近总结iOS本地化策略，，还是5种策略，Plist，NSUserDefault，归档，sqlite，苹果自带的coreData

Plist

这是比较常用的明文本地存储方式，全名属性列表，像app的配置文件等的信息，一般后缀为.plist，文件的格式以XML的形式展现。优点就是用起来比较方便，缺点就是容易暴露信息。

因为是本地的东西，所以需要存储路径，先创建本地路径

    //plist文件的创建
    //获取应用程序沙盒的Documents目录
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *plistPath = [paths objectAtIndex:0];
    //创建字典 保存数据
    NSMutableDictionary *dictTest=[[NSMutableDictionary alloc]init];
    [dictTest setObject:@"1" forKey:@"test"];
    //得到完整的文件名
    NSString *filename = [plistPath stringByAppendingPathComponent:@"test.plist"];
    //输入写入
    [dictTest writeToFile:filename atomically:YES];
    //plist文件的读取
    NSMutableDictionary *dictRead = [[NSMutableDictionary alloc] initWithContentsOfFile:filename];
    NSLog(@"dictRead:%@",dictRead);

NSUserDefault

这是苹果官方指定的存储方式，而且是单例的形式，就像是通知，用起来十分方便，但是一般是存比较小的数据，比如用户的个人信息等，如果存储大的数据，如果还不是异步线程保存会卡住主线程

他的存取方式类似于字典的键值存取，但是字典只能存取对象，字符串等的信息，但是NSUserDefault可以存取例如BOOL，Interger等的类型。

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    //存储
    [defaults setObject:@"abc" forKey:@"name"];
    [defaults setInteger:10 forKey:@"age"];
    
    UIImage *image =[UIImage imageNamed:@"testImage.jpg"];
    NSData *imageData = UIImageJPEGRepresentation(image, 1);//把image归档为NSData
    [defaults setObject:imageData forKey:@"image"];
    
    //读取
    NSString *nameRead = [defaults objectForKey:@"name"];
    NSInteger ageRead = [defaults integerForKey:@"age"];
    
    NSData *imageReadData = [defaults dataForKey:@"image"];
    UIImage *imageRead = [UIImage imageWithData:imageReadData];
    NSLog(@"nameRead:%@ ageRead:%ld imageRead:%@",nameRead,ageRead,imageRead);

归档作为轻量级的存储方案(相对于数据库)，既可以利用NSCoding存储对象，又可以存储IOS的遵守NSCoding的NSString等的对象，这样更适合于日常的开发。

归档分为系统归档和自定义归档

系统归档

    //获取应用程序沙盒的Documents目录
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *plistPath = [paths objectAtIndex:0];
    //创建字典 保存数据
    NSMutableDictionary *dictTest=[[NSMutableDictionary alloc]init];
    [dictTest setObject:@"1" forKey:@"test"];
    //得到完整的文件名
    NSString *filename = [plistPath stringByAppendingPathComponent:@"test.archiver"];
    //写入
    [NSKeyedArchiver archiveRootObject:dictTest toFile:filename];
    //读取
    NSMutableDictionary *dictRead = [NSKeyedUnarchiver unarchiveObjectWithFile:filename];
    NSLog(@"dictRead:%@",dictRead);

自定义归档

自定义归档通常需要自定义继承于NSObject的对象

#import <Foundation/Foundation.h>

@interface Engine : NSObject <NSCoding>
@property (nonatomic,copy) NSString *name;
@property (nonatomic) int weight;
@end

#import "Engine.h"

@implementation Engine

//归档调用
- (void)encodeWithCoder:(NSCoder *)aCoder{
    [aCoder encodeObject:self.name forKey:@"name"];
    [aCoder encodeInt:self.weight forKey:@"weight"];
}
//读档调用
- (id)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super init]) {
        self.name = [aDecoder decodeObjectForKey:@"name"];
        self.weight = [aDecoder decodeIntForKey:@"weight"];
    }
    return self;
}


@end

具体的写入和读取

    //获取应用程序沙盒的Documents目录
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
    NSString *plistPath = [paths objectAtIndex:0];
    //得到完整的文件名
    NSString *filename = [plistPath stringByAppendingPathComponent:@"test.archiver"];
    
    Engine *engine = [[Engine alloc] init];
    engine.name = @"德国";
    engine.weight = 10;
    //写入
    [NSKeyedArchiver archiveRootObject:engine toFile:filename];
    //读取
    Engine *engineRead = [NSKeyedUnarchiver unarchiveObjectWithFile:filename];
    NSLog(@"name:%@ engine:%d",engineRead.name,engineRead.weight);

以上就是三种iOS轻量级的存取方式，demo比较简单

其中有小技巧

1 创建一个父对象 在.m中导入MJExtension的声明

MJExtensionCodingImplementation

可以自动归档和解档对象之后继承父类的对象可以直接存取，方便快捷