（IOS）删除NSUserDefaults所有记录

//方法一

NSString *appDomain = [[NSBundle mainBundle] bundleIdentifier];

[[NSUserDefaults standardUserDefaults] removePersistentDomainForName:appDomain];

//方法二

- (void)resetDefaults {

    NSUserDefaults * defs = [NSUserDefaults standardUserDefaults];

    NSDictionary * dict = [defs dictionaryRepresentation];

    for(idkeyindict) {

        [defsremoveObjectForKey:key];

    }

    [defssynchronize];

}

// 方法三

[[NSUserDefaults standardUserDefaults] setPersistentDomain:[NSDictionary dictionary] forName:[[NSBundle mainBundle] bundleIdentifier]];