IOS数据存储

快来打我* 2022-08-01 13:42 157阅读 0赞

//
    //  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