iOS存储的几种方式

1.写文件

        NSData *dat = [[NSDataalloc]initWithContentsOfURL:[NSURLURLWithString:imageUrl]];

        NSString *fullPath = [[NSHomeDirectory()stringByAppendingPathComponent:@"Documents"]stringByAppendingPathComponent:[NSStringstringWithFormat:@"DocumentDataF"]];

        [datwriteToFile:fullPath atomically:NO];

       UIImage *img = [UIImage imageWithContentsOfFile:fullPath];

2.对象序列化存储

2.1导入第三方MJExtension文件

2.2将你要存入的模型.m文件里加上

MJCodingImplementation

2.3使用下列方法存取

保存数组(自定义对象)到NSUserDefaults

+ (void)userDefaultsArchiveCustomArray:(NSMutableArray *)array withKey:(NSString *)key{

    NSData *data = [NSKeyedArchiverarchivedDataWithRootObject:array];

    NSUserDefaults *userDefaults = [NSUserDefaultsstandardUserDefaults];

    [userDefaults setObject:data forKey:key];

    [userDefaults synchronize];

}

从NSUserDefaults解析出数组(自定义对象)

+ (NSMutableArray *)userDefaultsUnarchiveArrayWithKey:(NSString *)key{

    NSUserDefaults *userDefaults = [NSUserDefaultsstandardUserDefaults];

    NSData *data = [userDefaults objectForKey:key];

    NSMutableArray *array = (NSMutableArray *)[NSKeyedUnarchiverunarchiveObjectWithData:data];

    return array;

}

3.数据库（sqlite）

导入FMDataBase文件

实现数据酷的增删改查

4.图片缓存

导入SDWebImage文件