IOS--初识缓存

#import <Foundation/Foundation.h>


@interface NSUserDefaults (HMReader)

/**
 * 用于缓存app自有业务相关的数据信息
 */
+ (instancetype)hm_shareUserDefaults;

@end

#import "NSUserDefaults+HMReader.h"

@implementation NSUserDefaults (HMReader)

+ (instancetype)hm_shareUserDefaults
{
    static NSUserDefaults *__instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        NSString *bundleId = [NSBundle mainBundle].bundleIdentifier;
        bundleId = [bundleId stringByAppendingString:@".hm"];
        __instance = [[NSUserDefaults alloc] initWithSuiteName:bundleId];
    });
    return __instance;
}

@end

#define kisFirstComeSiteViewKey  @"com.hmreader.HMBookSiteWebViewController.FirstComeSite"

//缓存存储
[[NSUserDefaults hm_shareUserDefaults] setObject:@isFirstLoad forKey:kisFirstComeSiteViewKey];
    [[NSUserDefaults hm_shareUserDefaults] synchronize];

//读取缓存
NSString *hasShow = [[NSUserDefaults hm_shareUserDefaults] objectForKey:kisFirstComeSiteViewKey];