数据存储之偏好设置NSUserDefaults

NSUserDefaults做数据存储也是比较常用，适合轻量级的本地数据存储，读取也很方便。

一、支持的数据类型如下图(NSString、NSArray、NSDictionary、NSData、NSInteger、float、double、BOOL、NSURL)

二、使用Demo

//
//  ViewController.m
//  NSUserDefaults
//
//  Created by City--Online on 15/4/21.
//  Copyright (c) 2015年 CYW. All rights reserved.
//
 
#import "ViewController.h"
 
@interface ViewController ()
 
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
    [super viewDidLoad];
#if 0  //保存数据
    NSString *mystring=@"cuiyw";
    int myint=12;
    float myfloat=12.0;
    double mydouble=12.00;
    NSDate *mydate=[NSDate date];
    NSArray *myarray=[[NSArray alloc]initWithObjects:@"a",@"b",@"c",nil];
    NSDictionary *mydic=[[NSDictionary alloc]initWithObjects:@[@"cui",@"yanwei"] forKeys:@[@"1",@"2"]];
    BOOL mybool=YES;
    NSData *mydata=[mystring dataUsingEncoding:NSUTF8StringEncoding];
    NSURL *myUrl=[[NSURL alloc]initWithString:@"http://www.baidu.com"];
    NSUserDefaults *userDefaults=[NSUserDefaults standardUserDefaults];
    // 设置数据
    [userDefaults setObject:mystring forKey:@"mystring"];
    [userDefaults setInteger:myint forKey:@"myint"];
    [userDefaults setDouble:mydouble forKey:@"mydouble"];
    [userDefaults setFloat:myfloat forKey:@"myfloat"];
    [userDefaults setObject:mydate forKey:@"mydate"];
    [userDefaults setObject:myarray forKey:@"myarray"];
    [userDefaults setObject:mydic forKey:@"mydic"];
    [userDefaults setBool:mybool forKey:@"mybool"];
    [userDefaults setObject:mydata forKey:@"mydata"];
    [userDefaults setURL:myUrl forKey:@"myUrl"];
    //数据立即保存
    [userDefaults synchronize];
    NSLog(@"%@",NSTemporaryDirectory());
#endif
#if 1
    NSUserDefaults *userDefaults=[NSUserDefaults standardUserDefaults];
    NSString *myString=[userDefaults stringForKey:@"mystring"];
    NSInteger myint=[userDefaults integerForKey:@"myint"];
    float myfloat=[userDefaults floatForKey:@"myfloat"];
    NSDate *mydate=[userDefaults objectForKey:@"mydate"];
    NSArray *myarray=[userDefaults arrayForKey:@"myarray"];
    NSDictionary *mydic=[userDefaults dictionaryForKey:@"mydic"];
    BOOL mybool=[userDefaults boolForKey:@"mybool"];
    NSString *mydata=[[NSString alloc]initWithData:[userDefaults dataForKey:@"mydata"] encoding:NSUTF8StringEncoding] ;
    NSURL *myUrl=[userDefaults URLForKey:@"myUrl"];
    NSLog(@"myString:%@\nmyint:%ld\nmyfloat:%lf\nmydate:%@\nmyarray:%@\nmydic:%@\nmybool:%d\nmydata:%@\nmyUrl:%@",myString,myint,myfloat,mydate,myarray,mydic,mybool,mydata,myUrl);
    //可以通过removeObjectForKey移除
    //[userDefaults removeObjectForKey:@"mystring"];
     
#endif
}
 
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
 
@end

三、运行结果

NSUserDefaults保存在Library/Preferences下