ios 关于如何在app里面设置版本更新功能

#import "ViewController.h"

@interface ViewController ()
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.title = @"版本检测更新";
    self.view.backgroundColor = [UIColor whiteColor];
    [self checkVersion];   //检测升级  
}

-(void)checkVersion
{
    NSString *newVersion;
    NSURL *url = [NSURL URLWithString:@"http://itunes.apple.com/cn/lookup?id=1139094792"];//这个URL地址是该app在iTunes connect里面的相关配置信息。其中id是该app在app store唯一的ID编号。
    NSString *jsonResponseString = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:nil];
    NSLog(@"通过appStore获取的数据信息：%@",jsonResponseString);
    
    NSData *data = [jsonResponseString dataUsingEncoding:NSUTF8StringEncoding];
//    解析json数据
    id json = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
    NSArray *array = json[@"results"];
    for (NSDictionary *dic in array) {
        newVersion = [dic valueForKey:@"version"];
    }
    
    NSLog(@"通过appStore获取的版本号是：%@",newVersion);
    //获取本地软件的版本号
    NSString *localVersion = [[[NSBundle mainBundle]infoDictionary] objectForKey:@"CFBundleVersion"];
    NSString *msg = [NSString stringWithFormat:@"你当前的版本是V%@，发现新版本V%@，是否下载新版本？",localVersion,newVersion];
    //对比发现的新版本和本地的版本
    if ([newVersion floatValue] > [localVersion floatValue])
    {
        UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"升级提示"message:msg preferredStyle:UIAlertControllerStyleAlert]; 
        [self presentViewController:alert animated:YES completion:nil];
       
        [alert addAction:[UIAlertAction actionWithTitle:@"现在升级" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"https://itunes.apple.com/cn/app/yi-ka-tongbic-ban/id1139094792?l=en&mt=8"]];这里写的URL地址是该app在app store里面的下载链接地址，其中ID是该app在app store对应的唯一的ID编号。
            NSLog(@"点击现在升级按钮");
        }]];
        
        [alert addAction:[UIAlertAction actionWithTitle:@"下次再说" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            NSLog(@"点击下次再说按钮");
        }]];
    }
}