#define APP_URL @"http://itunes.apple.com/cn/lookup?id=1169362912"

//检测商店的版本

    AFHTTPSessionManager *mgr = [AFHTTPSessionManager manager];

    [mgr POST:APP_URL parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {

        NSLog(@"------------------------------------------------------------------------%@",responseObject);

        /*responseObject是个字典{}，有两个key

         KEYresultCount = 1//表示搜到一个符合你要求的APP

         results =（）//这是个只有一个元素的数组，里面都是app信息，那一个元素就是一个字典。里面有各种key。其中有 trackName （名称）trackViewUrl = （下载地址）version （可显示的版本号）等等

         */

        //具体实现为

        NSArray *arr = [responseObject objectForKey:@"results"];

        NSDictionary *dic = [arr firstObject];

        NSString *versionStr = [dic objectForKey:@"version"];

        NSString *trackViewUrl = [dic objectForKey:@"trackViewUrl"];

        NSString *releaseNotes = [dic objectForKey:@"releaseNotes"];//更新日志

        //NSString* buile = [[NSBundle mainBundle] objectForInfoDictionaryKey: (NSString*) kCFBundleVersionKey];build号

        // 加测当前的版本

        NSString *app_Version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];

        NSLog(@"------------------------------------------------------------------------%@",app_Version);

        if ([self compareVersionsFormAppStore:versionStr WithAppVersion:app_Version]) {

            UIAlertController *alertVC = [UIAlertController alertControllerWithTitle:[NSString stringWithFormat:@"发现新版本:%@",versionStr] message:releaseNotes preferredStyle:UIAlertControllerStyleAlert];

            UIAlertAction *cancelAction  = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

                NSLog(@"点击了取消");

            }];

            UIAlertAction *OKAction  = [UIAlertAction actionWithTitle:@"更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

                NSLog(@"点击了知道了");

                NSURL * url = [NSURL URLWithString:trackViewUrl];//itunesURL = trackViewUrl的内容

                [[UIApplication sharedApplication] openURL:url];

            }];

            [alertVC addAction:cancelAction];

            [alertVC addAction:OKAction];

            [self presentViewController:alertVC animated:YES completion:nil];

        }

    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {

        NSLog(@"");

    }];

//比较版本的方法，在这里我用的是Version来比较的

- (BOOL)compareVersionsFormAppStore:(NSString*)AppStoreVersion WithAppVersion:(NSString*)AppVersion {

    BOOL littleSunResult = false;

    NSMutableArray* a = (NSMutableArray*) [AppStoreVersion componentsSeparatedByString: @"."];

    NSMutableArray* b = (NSMutableArray*) [AppVersion componentsSeparatedByString: @"."];

    while (a.count < b.count) { [a addObject: @"0"]; }

    while (b.count < a.count) { [b addObject: @"0"]; }

    for (int j = 0; j<a.count; j++) {

        if ([[a objectAtIndex:j] integerValue] > [[b objectAtIndex:j] integerValue]) {

            littleSunResult = true;

            break;

        }else if([[a objectAtIndex:j] integerValue] < [[b objectAtIndex:j] integerValue]){

            littleSunResult = false;

            break;

        }else{

            littleSunResult = false;

        }

    }

    return littleSunResult;//true就是有新版本，false就是没有新版本

}