Bugly 统计，HappytDNS 导致 崩溃很频繁。

NSGenericException *** Collection <__NSArrayM: 0x1513962d0> was mutated while being enumerated. 解析原始 0 CoreFoundation ___exceptionPreprocess + 124 1 libobjc.A.dylib objc_exception_throw + 56 2 CoreFoundation -[NSException name] 3 HappyDNS records2Ips + 208 4 HappyDNS -[QNDnsManager queryInternalWithDomain:] + 1472 5 HappyDNS -[QNDnsManager queryWithDomain:] + 228 6 Qiniu -[QNSessionManager sendRequest:withCompleteBlock:withProgressBlock:withCancelBlock:] + 944 7 libdispatch.dylib __dispatch_call_block_and_release + 24 8 libdispatch.dylib __dispatch_client_callout + 16 9 libdispatch.dylib __dispatch_root_queue_drain + 2140 10 libdispatch.dylib __dispatch_worker_thread3 + 112 11 libsystem_pthread.dylib _pthread_wqthread + 1092 12 libsystem_pthread.dylib start_wqthread + 4

具体问题在 QNDnsManager.m 文件中, 对 queryInternalWithDomain 方法进行了异步调用，并且在@synchronized 块 中对 result 数组进行了更改，所以会导致崩溃， 建议在 records2Ips 方法中 的 for (QNRecord *r in records) 改为 for (QNRecord *r in [records copy]) 或者不要使用 for in 来进行循环。

static NSArray *records2Ips(NSArray *records) {
    NSMutableArray *array = [[NSMutableArray alloc] init];
    for (QNRecord *r in records) {    // 此处使用 for in  遍历会有问题
        [array addObject:r.value];
    }
    return array;
}

- (NSArray *)queryInternalWithDomain:(QNDomain *)domain {
    if (domain.hostsFirst) {
        NSArray *ret = [_hosts query:domain networkInfo:_curNetwork];
        if (ret != nil && ret.count != 0) {
            return ret;
        }
    }
    NSMutableArray *result;
    @synchronized(_cache) {
        if ([_curNetwork isEqualToInfo:[QNNetworkInfo normal]] && [QNNetworkInfo isNetworkChanged]) {
            [_cache removeAllObjects];
            _resolverStatus = 0;
        } else {
            result = [_cache objectForKey:domain.domain];
            if (result != nil && result.count > 1) {
                QNRecord *first = [result firstObject];
                [result removeObjectAtIndex:0];    // 此处对 result 进行了修改
                [result addObject:first];
            }
        }
    }

    if (result != nil && result.count > 0) {
        QNRecord *record = [result objectAtIndex:0];
        if (![record expired:[[NSDate date] timeIntervalSince1970]]) {
            return records2Ips(result);
        }
    }
...

Hi，

network failure: Error Domain=NSURLErrorDomain Code=-999 "cancelled" UserInfo={NSErrorFailingURLStringKey=https://54.255.32.12/v1.0/report, NSErrorFailingURLKey=https://54.255.32.12/v1.0/report, _NSURLErrorRelatedURLSessionTaskErrorKey=(
    "LocalDataTask <6B1DA05D-25CB-4DA8-9368-A7CF0FC40CCD>.<7>"
), _NSURLErrorFailingURLSessionTaskErrorKey=LocalDataTask <6B1DA05D-25CB-4DA8-9368-A7CF0FC40CCD>.<7>, NSLocalizedDescription=cancelled}

我就是简单的替换了NSUurl，需要该如何才能在接下来的https请求生效呢，有没有集成http请求的demo呢？

我看网上说需要将http请求中的header中的字段host改成原始的域名，但是尝试后也没有效果。

@synchronized(_cache) {
        if ([_curNetwork isEqualToInfo:[QNNetworkInfo normal]] && [QNNetworkInfo isNetworkChanged]) {
            [_cache removeAllObjects];
            _resolverStatus = 0;
        } else {
            result = [_cache objectForKey:domain.domain];
        }
    }

如题所述情况下，确认是走的else，得到的result是nil。并没有发现代码中有其他地方清cache

1.先pod 'HappyDNS', '~> 0.1.1'到项目中；

2.项目中使用QNDnsManager 返回ips; NSMutableArray *array = [[NSMutableArray alloc]init]; [array addObject:[QNResolver systemResolver]]; [array addObject:[[QNResolver alloc] initWithAddres:@"114.114.115.115"]]; QNDnsManager *dnsManager = [[QNDnsManager alloc] init:array networkInfo:[QNNetworkInfo normal]]; NSArray *ips = [dnsManager query:@"http://xxxx.com2.z0.glb.qiniucdn.com"];

3.请求七牛图片时使用ip替换域名http://xxxx.com2.z0.glb.qiniucdn.com，并设置HTTPHeadField; [SDWebImageManager.sharedManager.imageDownloader setValue:@"http://xxxx.com2.z0.glb.qiniucdn.com" forHTTPHeaderField:@"Host"]; 注：自己封装请求图片时使用[request setValue: @"http://xxxx.com2.z0.glb.qiniucdn.com" forHTTPHeaderField:@"Host"];

4.项目中因为图片还有其他来源，这里区分使用设置HTTPHeadField中Host; SDWebImageManager.sharedManager.imageDownloader.headersFilter = ^NSDictionary *(NSURL *url, NSDictionary *headers) { NSMutableDictionary *mutableHeaders = [headers mutableCopy]; [mutableHeaders removeObjectForKey:@"Host"]; //是否为ip格式 if ([url.host rh_isIp]) { [mutableHeaders setValue:@"xxxx.com2.z0.glb.qiniucdn.com" forKey:@"Host"]; } return mutableHeaders; };

最后，谢谢longbai在此过程中提供的帮助，由于缺少相关文档，冒昧抛砖引玉，希望可以帮助到小伙伴们，欢迎一起交流！

release 里写了全面兼容 ipv6，不过我对照这片文章过了一下几个兼容点时，其中有一点

IPV4时只需要通过res_ninit进行初始化就可以获取，但是在IPV6环境下需要通过res_getservers()接口才能获取。

在0.3.3.1版本的 setup_dns_server 里只有使用 res_ninit ，这样也可以兼容 ipv6 吗？

多谢

QNDnsManager.h :135:14:

/**
 *    设置底层 业务统计 如connect 回调使用的Callback
 *
 *    @param dns 回调用的dnsmanager
 */
+ (void)setIpStatusCallback:(QNIpStatusCallback)block;

导入系统库时"#include "string.h" " 这种写法是不规范的，应该修改为 "#include <string.h>"，后面的两个也一样。 使用了第一种写法，如果有第三方库中定义了string.h 文件的话，两个库在一起很可能就会报错。

当然，我在这里提这个问题正式因为我们在使用 grpc的时候遇到这个尴尬的问题。所以，为了以后同学能够更好的使用，希望你们能够采纳我的建议，修改掉代码里的这种用法。

期待你们的回复

除了这个 nsurlconnection 方法之外

NSData *data = [NSURLConnection sendSynchronousRequest:urlRequest
                    returningResponse:&response
                    error:&httpError];

因为我需要修改源代码，所以想手动集成，结果报错了。 Undefined symbols for architecture arm64: "_res_9_setservers", referenced from: _setup_dns_server in QNResolvUtil.o "_res_9_ninit", referenced from: +[QNResolver systemDnsServer] in QNResolver.o _setup_dns_server in QNResolvUtil.o "_res_9_getservers", referenced from: +[QNResolver systemDnsServer] in QNResolver.o "_res_9_ns_name_uncompress", referenced from: _query_ip_v4 in QNResolver.o "_res_9_ns_parserr", referenced from: _query_ip in QNTxtResolver.o _query_ip_v4 in QNResolver.o "_res_9_nquery", referenced from: _query_ip in QNTxtResolver.o _query_ip_v4 in QNResolver.o "_res_9_ns_initparse", referenced from: _query_ip in QNTxtResolver.o _query_ip_v4 in QNResolver.o "_res_9_ndestroy", referenced from: _query_ip in QNTxtResolver.o _query_ip_v4 in QNResolver.o +[QNResolver systemDnsServer] in QNResolver.o ld: symbol(s) not found for architecture arm64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

请求某一地址：http://super.bxr.im/b/goods?anonymous=0&anonymous_id=90668dbc-1ca4-4872-b43e-1fa7489f5d19&channel_id=1&xrk_is_share=0&token=f066ff5a574f17a85d359af574c22a02&f_source=app-index-tool-2&sso_id=3205906

dns解析为：http://122.13.170.7/b/goods?anonymous=0&anonymous_id=90668dbc-1ca4-4872-b43e-1fa7489f5d19&channel_id=1&xrk_is_share=0&token=f066ff5a574f17a85d359af574c22a02&f_source=app-index-tool-2&sso_id=3205906 并设置请求头host：super.bxr.im

请求成功，但是response的Set-Cookie，貌似没保存到。

再请求：http://122.13.170.7/b/commission/3205906?t=1464576038824&ct_sso_id=3205906&ct_channel_id=1&ct_f_source=
没有前一个请求的返回cookie，导致请求失败

这个如何解决？