iOS检查版本更新

-(void)onCheckVersion
{
    dispatch_queue_t queue =  dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_async(queue, ^{
        NSDictionary *infoDic = [[NSBundle mainBundle] infoDictionary];
        NSString *currentVersion = [infoDic objectForKey:@"CFBundleShortVersionString"];
        NSString *URL = @"http://itunes.apple.com/lookup?id=xxx";
        NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
        [request setURL:[NSURL URLWithString:URL]];
        [request setHTTPMethod:@"POST"];
        NSHTTPURLResponse *urlResponse = nil;
        NSError *error = nil;
        NSData *recervedData = [NSURLConnection sendSynchronousRequest:request returningResponse:&urlResponse error:&error];
        NSString *results = [[NSString alloc] initWithBytes:[recervedData bytes] length:[recervedData length] encoding:NSUTF8StringEncoding];
        NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:[results dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:nil];
        NSArray *infoArray = [dic objectForKey:@"results"];
        if ([infoArray count]) {
            NSDictionary *releaseInfo = [infoArray objectAtIndex:0];
            NSString *lastVersion = [releaseInfo objectForKey:@"version"];
            if (([self versionNumberConVersion:lastVersion] >[self versionNumberConVersion:currentVersion])) {
                alert = [UIAlertController alertControllerWithTitle:@"发现新版本" message:[releaseInfo objectForKey:@"releaseNotes"] preferredStyle:UIAlertControllerStyleAlert];
                UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"暂不" style:UIAlertActionStyleCancel handler:nil];
                [alert addAction:cancelAction];
                UIAlertAction *sureAction = [UIAlertAction actionWithTitle:@"更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
//                    NSURL *url = [NSURL URLWithString:@"https://itunes.apple.com/cn/app/xxname/idxxx?l=en&mt=8"];
                    NSURL *url = [NSURL URLWithString:@"itms-apps://itunes.apple.com/cn/app/xxname/idxxx?mt=8"];
                    [[UIApplication sharedApplication]openURL:url];
                }];
                [alert addAction:sureAction];
                dispatch_async(dispatch_get_main_queue(), ^{
                     [self presentViewController:alert animated:YES completion:nil];
                });

            }
        }
    });
}

-(int)versionNumberConVersion:(NSString*)version{
    //假如版本号1.5.1 截图如下 这边需要确定几位小数，来确定数组个数。
    int num1 = 0;
    NSArray *ary = [version componentsSeparatedByString:@"."];
    if (ary.count) {
        for (int i = 0; i<ary.count; i++) {
            if (i==0) {
                num1 = [ary[0] intValue]*10000;
            }else if (i==1){
                num1 = [ary[0] intValue]*10000+[ary[1] intValue]*100;
            }else if (i==2){
                num1 = [ary[0] intValue]*10000+[ary[1] intValue]*100+[ary[2] intValue];
            }else if (i>=3){
                num1 = [ary[0] intValue]*10000+[ary[1] intValue]*100+[ary[2] intValue];
            }
        }

    }
    //NSLog(@"版本号%d",num1);
    return num1;
}