// 写缓存
+ (void)writeLocalCacheData:(NSData *)data withKey:(NSString *)key {
    // 设置存储路径
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]
                            stringByAppendingPathComponent:key];
    // 判读缓存数据是否存在
    if ([[NSFileManager defaultManager] fileExistsAtPath:cachesPath]) {
        // 删除旧的缓存数据
        [[NSFileManager defaultManager] removeItemAtPath:cachesPath error:nil];
    }
    // 存储新的缓存数据
    [data writeToFile:cachesPath atomically:YES];
}

// 读缓存
+ (NSData *)readLocalCacheDataWithKey:(NSString *)key {
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]
                            stringByAppendingPathComponent:key];
    // 判读缓存数据是否存在
    if ([[NSFileManager defaultManager] fileExistsAtPath:cachesPath]) {
        // 读取缓存数据
        return [NSData dataWithContentsOfFile:cachesPath];
    }
    return nil;
}

// 删缓存
+ (void)deleteLocalCacheDataWithKey:(NSString *)key {
    NSString *cachesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0]
                            stringByAppendingPathComponent:key];
    // 判读缓存数据是否存在
    if ([[NSFileManager defaultManager] fileExistsAtPath:cachesPath]) {
        // 删除缓存数据
        [[NSFileManager defaultManager] removeItemAtPath:cachesPath error:nil];
    }
}