IOS数据存储

//
//  DataViewController.m
//  AppUI组件学习
//
//  Created by 麦子 on 15/6/19.
//  Copyright (c) 2015年 麦子. All rights reserved.
//

#import "DataViewController.h"

@interface DataViewController (){

UITextView *myText;

}

@end

@implementation DataViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.title = @"数据库学习";
[self createView];

// 查看数据是否存在
NSString *path = NSHomeDirectory();
path = [path stringByAppendingPathComponent:@"login.txt"];

/**
需要注意，中文的时候，需要用 NSUTF16StringEncoding ＝＝ NSUnicodeStringEncoding
系统生成的时候可能就是 Unicode 创建的。 获取的时候，还是需要这个NSUTF16StringEncoding
*/
NSError *er = nil;
NSString *msg = [NSString stringWithContentsOfFile:path encoding:NSUTF16StringEncoding error:&er];

if (er) {
　　NSLog(@"失败原因:%@",[er description]);
}

NSLog(@"%@---%@",path,msg);
if (msg != nil) {
myText.text = msg;
}else{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"文件" message:@"登陆信息不存在" delegate:self cancelButtonTitle:@"知道" otherButtonTitles:nil, nil];
[alert show];
}

NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
NSString *userName = [def objectForKey:@"userName"];
//    [def removeObjectForKey:@"userName"];删除
NSLog(@"---%@",userName);

}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}

- (void)createView{
UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(20, 80, 100, 50);
btn.tag = 1;
[btn setTitle:@"获取沙河路径" forState:UIControlStateNormal];
[btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];

UIButton *btnA = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btnA.frame = CGRectMake(150, 80, 100, 50);
btnA.tag = 2;
[btnA setTitle:@"文件保存" forState:UIControlStateNormal];
[btnA addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];

myText = [[UITextView alloc] init];
myText.frame = CGRectMake(80, 250, 200, 100);
myText.textAlignment = NSTextAlignmentCenter;
myText.backgroundColor = [UIColor orangeColor];
myText.textColor = [UIColor redColor];

[self.view addSubview:myText];
[self.view addSubview:btnA];
[self.view addSubview:btn];

}

- (void)btnClick:(UIButton *)button{
switch (button.tag) {
case 1:{
// 沙盒是一个独立的空间，应用和应用之间的数据不能共享，我们需要保持一些数据的时候，可以在这里创建文件进行记录，保存数据

// 字符串数据保存
NSString *path = NSHomeDirectory();
path = [path stringByAppendingPathComponent:@"login.txt"];
NSString *message = @"我需要保存的数据";
[message writeToFile:path atomically:true];
// documents , library, tmp , 根目录下面的三个目录
NSArray *documentArray =  NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true);
NSArray *libraryArray =  NSSearchPathForDirectoriesInDomains(NSLibraryDirectory, NSUserDomainMask, true);

// 零时目录，是由系统进行管理的。
NSString *temp = NSTemporaryDirectory();
NSLog(@"%@",temp);
break;

}
case 2:{ // 文件保存,写入数据
// 集合数据保存
NSArray *dataArray = [NSArray arrayWithObjects:@"麦子A",@"麦子B",@"麦子C",@"麦子D",@"麦子E",@"麦子F",@"麦子G", nil];
NSString *path = NSHomeDirectory();
path = [path stringByAppendingPathComponent:@"maizi_today.plist"];
[dataArray writeToFile:path atomically:true];
NSLog(@"%@",path);

;

// 字典保存数据 --- 存入的只能是对象
NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"小强",@"name",@"男",@"sex",[NSNumber numberWithInt:18],@"age", nil];

NSString *userPath = [NSHomeDirectory() stringByAppendingPathComponent:@"user_message.plist"];
NSLog(@"%@",userPath);
[dic writeToFile:userPath atomically:true];

// 自定义类，必须要进行归档，才能存入磁盘。

//
NSUserDefaults *def = [NSUserDefaults standardUserDefaults];
[def setValue:@"小名" forKey:@"userName"];
[def synchronize];

break;
}

default:
break;
}

}

@end