sandBox 简单对象的写入，读取

//
//  ViewController.m
//  sandBox
//
//  Created by zhaoguodong on 16/6/24.
//  Copyright © 2016年 zhaoguodong. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    NSString *sandBoxpath = NSHomeDirectory();
    # #注意每个文件夹的名字，大小写不能错
    /**
     *  每个沙盒路径下都有三个文件夹
     *Documents 是最常用的，可以储存一些不太大的数据，plist、文本、splite。它会和itunes同步
！
     *Library
          caches:储存大容量的数据，caches路径的文件不会和itunes同步
          preference:储存用户设置。（偏好设置）
      tmp 临时文件夹，不进行同步，当设备重启,就会清空。
     */
    
    
    // 拼接路径获取documents路径
    NSString *path =  [sandBoxpath stringByAppendingPathComponent:@"Documents"];
   
    NSLog(@"%@",path);
    /**
     *  直接获取路径
     *
     *  @第一个参数:寻找的哪一个文件夹
     *  @第二个参数:用户沙盒主目录
     *  @第三个参数:如果为 NO 则不能完成读写操作
     */
    NSString *path1 = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject;
    NSLog(@"%@",path1);
    
    
    //获取preference  一般通过NSuserDefaults
    [[NSUserDefaults standardUserDefaults] setObject:@"UI" forKey:@"iOS"];
    NSLog(@"%@",[[NSUserDefaults standardUserDefaults] objectForKey:@"iOS"]);
    
    

    [self SimpleTypes];
  
    
    
    // Do any additional setup after loading the view, typically from a nib.
}

#pragma mark---------------简单数据写入、读取----------
- (void)SimpleTypes{
   //拼接写入文件的文件路径
    
    NSString *documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject;
    
    NSString *filepath = [documentsPath stringByAppendingPathComponent:@"file.txt"];
    //吧String写入文件
    NSString *string = @"老衲是文字";
    BOOL isWriting = [string writeToFile:filepath atomically:YES encoding:NSUTF8StringEncoding error:nil];
    if (isWriting) {
        NSLog(@"成功");
    }else{
        NSLog(@"失败");
    }
    
    
    //读取数据
    NSString *readString = [NSString stringWithContentsOfFile:filepath encoding:NSUTF8StringEncoding error:nil];
    
    NSLog(@"%@",readString);
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

打印结果