用archive保存图片到本地

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    //初始化背景图
    imageView=[[UIImageView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];
    imageView.backgroundColor=[UIColor redColor];
    [self.view addSubview:imageView];
    
    //将图片保存
    [self archive];
    
    //提取保存在本地的图片
    [self unarchive];
    

}
#pragma -mark -functions
//归档
-(void)archive
{
    NSData *data=[NSKeyedArchiver archivedDataWithRootObject:[UIImage imageNamed:@"1.jpg"]];
    NSUserDefaults *imageDefault = [NSUserDefaults standardUserDefaults];
    [imageDefault setObject:data forKey:@"image"];
    [imageDefault synchronize];

}
//反归档
-(void)unarchive
{
    NSData* data = [[NSUserDefaults standardUserDefaults]objectForKey:@"image"];
    id image= [NSKeyedUnarchiver unarchiveObjectWithData:data];
    imageView.image=image;
    

}