iOS针对检测版本更新

// 先获取当前工程项目版本号
    NSDictionary *infoDic=[[NSBundle mainBundle] infoDictionary];
    NSLog(@"%@",infoDic);
    NSString *currentVersion=infoDic[@"CFBundleShortVersionString"];

// 从网络获取AppStore版本号
    NSError *error;
// STOREAPPID是你在AppStore对应自己App的ID 可在AppStore上找到 也可在iTunesConnect上找到
    NSData *response = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:[NSString stringWithFormat:@"https://itunes.apple.com/cn/lookup?id=%@",STOREAPPID]]] returningResponse:nil error:nil];
    if (response == nil) {
        NSLog(@"没有连接网络");
        return;
    }
    NSDictionary *appInfoDic = [NSJSONSerialization JSONObjectWithData:response options:NSJSONReadingMutableLeaves error:&error];
    if (error) {
        NSLog(@"UpdateAppError:%@",error);
        return;
    }

    NSArray *array = appInfoDic[@"results"];
    
    if (array.count < 1) {
        NSLog(@"此APPID为未上架的APP或者查询不到");
        return;
    }
    
    NSDictionary *dic = array[0];
    NSString *appStoreVersion = dic[@"version"];
    //打印版本号
    NSLog(@"当前版本号:%@\n商店版本号:%@",currentVersion,appStoreVersion);

// 设置版本号
    currentVersion = [currentVersion stringByReplacingOccurrencesOfString:@"." withString:@""];
    if (currentVersion.length==2) {
        currentVersion  = [currentVersion stringByAppendingString:@"0"];
    }else if (currentVersion.length==1){
        currentVersion  = [currentVersion stringByAppendingString:@"00"];
    }
    appStoreVersion = [appStoreVersion stringByReplacingOccurrencesOfString:@"." withString:@""];
    if (appStoreVersion.length==2) {
        appStoreVersion  = [appStoreVersion stringByAppendingString:@"0"];
    }else if (appStoreVersion.length==1){
        appStoreVersion  = [appStoreVersion stringByAppendingString:@"00"];
    }

// 当前版本号小于商店版本号,就更新
    if([currentVersion floatValue] < [appStoreVersion floatValue])
    {
        UIAlertController *alercConteoller = [UIAlertController alertControllerWithTitle:@"版本有更新" message:[NSString stringWithFormat:@"检测到新版本(%@),是否更新?",dic[@"version"]] preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *actionYes = [UIAlertAction actionWithTitle:@"更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            //此处加入自己应用在AppStore的地址，方便用户去更新，一种实现方式如下
            NSURL *url = [NSURL URLWithString:@"https://itunes.apple.com/cn/app/简书-创作你的创作/id888237539?mt=8"];
            
            [[UIApplication sharedApplication] openURL:url];
        }];
        UIAlertAction *actionNo = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
            
        }];
        [alercConteoller addAction:actionYes];
        [alercConteoller addAction:actionNo];
        [self presentViewController:alercConteoller animated:YES completion:nil];
    }else{
        NSLog(@"版本号比商店大 检测到不需要更新");
    }