iOS开发之一句代码检测APP版本的更新

• 提示更新效果图如下，当然也是可以自定义类似与AlertView相似的自定义view，如京东、网易云音乐都是自定义了这种提示框的view。以下只展示，从App Store获取到app信息、并解析app信息获取发布在App Store上的版本号与当前手机里安装的app版本号做对比，如果有更新就做提示。
• 在工程中新建一个NSObject类，将以下.h和.m文件中的代码拷贝至这个新建的类中。

• //
  //  HKCheckAppVersionMgr.h
  //  HKTyy
  //
  //  Created by isHakan on 17/3/24.
  //  Copyright © 2017年 liuhuakun. All rights reserved.
  //
  
  #import <Foundation/Foundation.h>
  
  @interface HKCheckAppVersionMgr : NSObject
  
  + (HKCheckAppVersionMgr *)sharedInstance;
  - (void)isUpdataApp:(NSString *)appId;
  
  @end
  

  　　

• //
  //  HKCheckAppVersionMgr.m
  //  HKTyy
  //
  //  Created by isHakan on 17/3/24.
  //  Copyright © 2017年 liuhuakun. All rights reserved.
  //
  
  #import "HKCheckAppVersionMgr.h"
  
  #import <UIKit/UIKit.h>
  
  @interface HKCheckAppVersionMgr ()<UIAlertViewDelegate>
  
  @property (nonatomic, strong) NSString *appId;
  
  @end
  
  @implementation HKCheckAppVersionMgr
  
  + (HKCheckAppVersionMgr *)sharedInstance
  {
      static HKCheckAppVersionMgr *instance = nil;
      
      static dispatch_once_t onceToken;
      dispatch_once(&onceToken, ^{
          
          instance = [[HKCheckAppVersionMgr alloc] init];
          
      });
      
      return instance;
  }
  
  - (void)isUpdataApp:(NSString *)appId
  {
      NSURL *appUrl = [NSURL URLWithString:[NSString stringWithFormat:@"http://itunes.apple.com/lookup?id=%@",appId]];
      NSString *appMsg = [NSString stringWithContentsOfURL:appUrl encoding:NSUTF8StringEncoding error:nil];
      NSDictionary *appMsgDict = [self jsonStringToDictionary:appMsg];
      NSDictionary *appResultsDict = [appMsgDict[@"results"] lastObject];
      NSString *appStoreVersion = appResultsDict[@"version"];
      float newVersionFloat = [appStoreVersion floatValue];//新发布的版本号
      
      NSString *currentVersion = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
      float currentVersionFloat = [currentVersion floatValue];//使用中的版本号
      
      //当前版本小于App Store上的版本&用户未点击不再提示
      if (currentVersionFloat<newVersionFloat && ![self isAlertUpdataAgain])
      {
          self.appId = appId;
          UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"检测到新版本，是否去更新？" delegate:self cancelButtonTitle:@"去更新" otherButtonTitles:@"下次再说",@"不再提示", nil];
          [alertView show];
      }
      
  }
  
  - (NSDictionary *)jsonStringToDictionary:(NSString *)jsonStr
  {
      if (jsonStr == nil)
      {
          return nil;
      }
      
      NSData *jsonData = [jsonStr dataUsingEncoding:NSUTF8StringEncoding];
      NSError *error;
      NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:jsonData
                                                           options:NSJSONReadingMutableContainers
                                                             error:&error];
      if (error)
      {
          //NSLog(@"json格式string解析失败:%@",error);
          return nil;
      }
      
      return dict;
  }
  
  
  #pragma mark UIAlertViewDelegate
  - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
  {
      if (buttonIndex==0)
      {
          [[UIApplication sharedApplication] openURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://itunes.apple.com/app/id%@",self.appId]]];
          return;
      }
      
      if (buttonIndex==2)
      {
          [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"IS_ALERT_AGAIN"];
          [[NSUserDefaults standardUserDefaults] synchronize];
          return;
      }
  }
  
  - (BOOL)isAlertUpdataAgain
  {
      BOOL res = [[NSUserDefaults standardUserDefaults] objectForKey:@"IS_ALERT_AGAIN"];
      return res;
  }
  
  @end
  

  　　

• 在需要检测App版本是否有更新的地方-[以下是以在ViewController处检测App版本更新为例]：

• //  ViewController.m
  //  Demo
  //
  //  Created by isHakan on 2017/7/21.
  //  Copyright © 2017年 liuhuakun. All rights reserved.
  //
  
  #import "ViewController.h"
  
  //引入‘头文件’
  #import "HKCheckAppVersionMgr.h"
  
  //发布在App Store的Apple ID
  #define kYourAppleID @"1234567890"
  
  @interface ViewController ()
  
  @end
  
  @implementation ViewController
  
  - (void)viewDidLoad
  {
      [super viewDidLoad];
      // Do any additional setup after loading the view, typically from a nib.
      
      //一句代码检测更新
      [[HKCheckAppVersionMgr sharedInstance] isUpdataApp:kYourAppleID];
  }
  
  - (void)didReceiveMemoryWarning
  {
      [super didReceiveMemoryWarning];
      // Dispose of any resources that can be recreated.
  }
  
  
  @end