.h文件

@interface CheckUpdateTool : NSObject

/**
 從蘋果服務器獲取版本
 */
+ (void)getVersionFromServer;

@end

.m文件

#import "CheckUpdateTool.h"
#import <UIKit/UIKit.h>

#define APPLEID @"AppleID"               /// App 在蘋果開發(fā)者中生成的Apple ID

@implementation CheckUpdateTool

+ (void)getVersionFromServer {
    // 取出本地的版本號
    NSDictionary *infoDictionary = [[NSBundle mainBundle] infoDictionary];
    NSString *app_build = [infoDictionary objectForKey:@"CFBundleShortVersionString"];
    
    /// 當前版本
    double currentVersion = [app_build stringByReplacingOccurrencesOfString:@"." withString:@""].doubleValue;
    
    //1.創(chuàng)建會話對象
    NSURLSession *session = [NSURLSession sharedSession];

    
    //2.根據(jù)會話對象創(chuàng)建task
    NSString *requestStr = [@"http://itunes.apple.com/cn/lookup?id=" stringByAppendingString:APPLEID];
    NSURL *url = [NSURL URLWithString:requestStr];
    
    //3.創(chuàng)建可變的請求對象
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    
    //4.修改請求方法為POST
    request.HTTPMethod = @"POST";
    
    //5.設置請求體
    request.HTTPBody = [@"" dataUsingEncoding:NSUTF8StringEncoding];
    
    //6.根據(jù)會話對象創(chuàng)建一個Task(發(fā)送請求）
    /*
     第一個參數(shù)：請求對象
     第二個參數(shù)：completionHandler回調（請求完成【成功|失敗】的回調）
     data：響應體信息（期望的數(shù)據(jù)）
     response：響應頭信息馆蠕，主要是對服務器端的描述
     error：錯誤信息，如果請求失敗惊奇，則error有值
     */
    NSURLSessionDataTask *dataTask = [session dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable responseObject, NSError * _Nullable error) {
        
        if (data) {
            
            //返回數(shù)據(jù)的處理邏輯
            NSDictionary *response = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];
            NSArray *appInfos = response[@"results"];
            if (!appInfos || appInfos.count <= 0) {
                return;
            }
            NSDictionary *appInfo = appInfos[0];
            
            //服務器版本
            double serverVersion = [appInfo[@"version"] stringByReplacingOccurrencesOfString:@"." withString:@""].doubleValue;
            
            /// 服務器版本大于本地版本
            if (serverVersion > currentVersion) {
                UIAlertController *al = [UIAlertController alertControllerWithTitle:@"發(fā)現(xiàn)新版本" message:appInfo[@"releaseNotes"] preferredStyle:UIAlertControllerStyleAlert];
                
                [al addAction:[UIAlertAction actionWithTitle:@"前往更新" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
                    /// 前往更新
                    NSString *str = [[NSString stringWithFormat:@"itms-apps://itunes.apple.com/app/id"] stringByAppendingString:APPLEID];
                    
                    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
                }]];
                [al addAction:[UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleDestructive handler:nil]];
                
                [[UIApplication sharedApplication].keyWindow.rootViewController presentViewController:al animated:YES completion:nil];
            }
        }

    }];
    
    //7.執(zhí)行任務
    [dataTask resume];
}


@end