前言：

各位同学大家好有段时间没有给大家更新文章 OS NSUserDefaults 数据缓存使用教程就想着分享给大家希望能帮助到各位同学的学习和工作，那么废话不多说我们正式开始

准备工作

安装xcode 这个大家·可以自己去appstore 搜索下载即可

image.png

具体实现

- (void)viewDidLoad {
    [super viewDidLoad];
    UIButton * btn= [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btn.frame=CGRectMake(100, 100, 80, 40);
    [btn setTitle:@"写入文件" forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(pressWrite) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
   
    UIButton * btnRead =[UIButton buttonWithType:UIButtonTypeRoundedRect];
    btnRead.frame=CGRectMake(100, 200, 80, 40);
    [btnRead setTitle:@"读取文件" forState:UIControlStateNormal];
    [btnRead addTarget:self action:@selector(presRead) forControlEvents:UIControlEventTouchUpInside];
    
    [self.view addSubview:btnRead];

}

我们写了一个2个 button 添加到ViewController中来模拟数据的写入和读取

写入数据

//写入数据
-(void)pressWrite{
    //定义一个用户默认的对象
    //不需要alloc  创建 用户默认数据对象的单例模式
    //standardUserDefaults  获取全局唯一的实力对象
    NSUserDefaults * ud = [NSUserDefaults standardUserDefaults];
    
    //存储字符串对象
    //可以将对象存储到文件中
    //p1 要存储的的对象 id
    //P2 对象的名字 key ：NSString
    [ud setObject:@"徐庆" forKey:@"name"];
    
    //存储数据对象
    //只能存储能够文件化的对象
    
    NSNumber * num =[NSNumber numberWithInt:100];
    [ud setObject:num forKey:@"NUM"];
   //不能存储不能文件化的对象
   // [ud setObject:self.view forKey:@"VIEW"];
    //存储整型数据
    [ud  setInteger:123 forKey:@"INT"];
    //存储布尔值
    [ud setBool:YES forKey:@"BOOL"];
    //存储浮点型数据
    [ud setFloat:1.555 forKey:@"FLOAT"];
    //创建一个可以文件化的数组
    NSArray *  array=[NSArray arrayWithObjects:@"11",@"22",@"33", nil];
    [ud setObject:array forKey:@"ARRAY"];
    [ud removeObjectForKey:@"ARRAY"];
}

读取数据

//读取数据
-(void)presRead{
    NSUserDefaults * ud =[NSUserDefaults standardUserDefaults];
    
    id object = [ud objectForKey:@"name"];
    
    NSString * name=(NSString*) object;
    NSLog(@"name =  %@", name);
    object= [ud  objectForKey:@"NUM"];
    
    NSNumber * num =(NSNumber *)object;
    
    NSLog(@"num  =%@",num);
    NSInteger iV=[ud  integerForKey:@"INT"];
    NSLog(@"iV =%ld", iV);
    BOOL bV=[ud boolForKey:@"BOOL"];
    float fV= [ud  floatForKey:@"FLOAT"];
    NSLog(@"bV =%d",bV);
    NSLog(@"fV =%f", fV);
    NSArray *  array=[ud objectForKey:@"ARRAY"];
    NSLog(@"array = %@",array);
}