需求：低版本正常使用，新版本提交审核；审核通过后，新版本正常，低版本提示更新。

app运行中的几种状态

• 第一次启动程序

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(nullable NSDictionary *)launchOptions NS_AVAILABLE_IOS(3_0);

• 从后台跳前台

- (void)applicationDidBecomeActive:(UIApplication *)application;

第一次启动后需要

 id first = [[NSUserDefaults standardUserDefaults] objectForKey:@"appVersion"];
 if (![first isKindOfClass:[NSString class]])
   {
     [self performSelectorOnMainThread:@selector(setupTheStart:) withObject:nil waitUntilDone:YES];
    }

请求服务端检测审核状态

服务端控制新版本发布后，旧版本是允许继续使用，还是强制更新。

-(void)setupTheStart:(NSDictionary *)userInfo
{
    __weak typeof(self) weakSelf = self;
    NSString * url = @"获取审核状态接口"
    [TIMHttpTool GET:url parameters:nil success:^(id responseObject) {
        if ([responseObject[@"code"] intValue] == 0)
        {
            NSDate *nowDate = [NSDate date];
            [ [NSUserDefaults standardUserDefaults] setObject:nowDate forKey:@"nowDate"];
            [dataUser synchronize];
            if ([responseObject[@"detail"][@"is_check"] intValue] == 0)
            {
                [NSUserDefaults saveInfo:@"" withKey:@"appState"];
            }
            else if([responseObject[@"detail"][@"is_check"] intValue] == 1)
            {
                [NSUserDefaults saveInfo:@"check" withKey:@"appState"];
            }
            switch ([responseObject[@"detail"][@"update"] intValue])
            {
                case 0:
                    [NSUserDefaults saveInfo:@"" withKey:@"UPDATE"];
                    break;
                case 1:// 可更新
                case 2:// 强制
                {
                    NSDictionary * dic = responseObject[@"detail"];
                    [[NSUserDefaults standardUserDefaults] setObject:dic forKey:@"UPDATE"];
                    [[NSUserDefaults standardUserDefaults] synchronize];
                    [weakSelf compareWith:responseObject[@"detail"]];
                }
                    break;
                default:
                    break;
            }
        }
        else
        {
            [NSUserDefaults saveInfo:@"" withKey:@"UPDATE"];
            [NSUserDefaults saveInfo:@"check" withKey:@"appState"];
        }
    } failure:^(NSError *error) {
        [NSUserDefaults saveInfo:@"" withKey:@"UPDATE"];
        [NSUserDefaults saveInfo:@"check" withKey:@"appState"];
    }];
}

强制更新

- (void)compareWith:(NSDictionary *)dic
{
    if (dic)
    {
        NSArray * infoArray = dic[@"update_detail"];
        NSMutableString * infoStr = [[NSMutableString alloc]init];
        for (int i = 0 ; i < infoArray.count; i++)
        {
            [infoStr appendString:[NSString stringWithFormat:@"%d、%@\n",i+1,infoArray[i]]];
        }
        
        UIAlertController * alertCon = [UIAlertController alertControllerWithTitle:@"更新提示" message: infoStr preferredStyle:UIAlertControllerStyleAlert];
        if ([dic[@"update"] intValue] == 1)
        {
            [alertCon addAction:[UIAlertAction actionWithTitle:@"现在更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){
                [[UIApplication sharedApplication ]openURL:[NSURL URLWithString:dic[@"redirect"]]];
                
            }]];
            
            [alertCon addAction:[UIAlertAction actionWithTitle:@"暂不更新" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action){
                [NSUserDefaults saveInfo:@"" withKey:@"UPDATE"];
            }]];
        }
        else if([dic[@"update"] intValue] == 2)
        {
            [alertCon addAction:[UIAlertAction actionWithTitle:@"现在更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){
                [[UIApplication sharedApplication ]openURL:[NSURL URLWithString:dic[@"redirect"]]];
                [[IMAPlatform sharedInstance] logout:^{
                    [[AppDelegate sharedAppDelegate] enterLoginUI];
                } fail:^(int code, NSString *err) {
                    [[AppDelegate sharedAppDelegate] enterLoginUI];
                }];
            }]];
            
            
        }
        [self.window.rootViewController  presentViewController:alertCon animated:YES completion:nil];
    }
}

登录后，本地存当前版本号

 [[NSUserDefaults standardUserDefaults] setObject:KAppVersion forKey:@"appVersion"];

appState当前状态：审核版: @"check" 正式版：@""

id state = [[NSUserDefaults standardUserDefaults] objectForKey:@"appState"];

获取app当前版本：

#define KAppVersion [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"]