簡談思路：

當app出現在應用前臺的時候，我們會在應用內檢測當前手機上安裝的app版本edition1，並且同時獲取app store中該app當前版本edition2（xx.xx.xx），對這二個版本做比較（去掉“.”edition換算成整形加減法），如果edition2大於edition1，說明有版本更新，在app store下載自動升級。

程式碼實現：

//

//APPUpdateManager.m

//MoveBand

//

#import "APPUpdateManager.h"

#import <UIKit/UIKit.h>

#import "ChangeLanguage.h"

@interface

APPUpdateManager ()<NSURLConnectionDataDelegate,UIAlertViewDelegate>

//{

//NSString *version; //版本資訊

//NSString *trackViewUrl; //app下載地址

//}

@property (nonatomic,copy) NSString *version;//版本資訊

@property (nonatomic,copy) NSString *trackViewUrl;//app下載地址

@end

@implementation APPUpdateManager

+ (instancetype

)shareInstance{

staticAPPUpdateManager *manager;

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

manager = [[APPUpdateManager alloc]init];

});

return manager;

}

- (instancetype)init

{

self = [super init];

if (self) {

[[NSNotificationCenterdefaultCenter]addObserver:selfselector:@selector

(appEnterForeground) name:UIApplicationWillEnterForegroundNotificationobject:nil];

}

return self;

}

- (void)appEnterForeground{

NSLog(@"will appEnterForeground");

NSInteger latestCheckTime = [[NSUserDefaultsstandardUserDefaults] integerForKey:@"latestCheckTime"];

NSInteger currentTimeInter = [[NSDate date]timeIntervalSince1970];

if (currentTimeInter -latestCheckTime > 3600 * 24) {

[[NSUserDefaultsstandardUserDefaults]setInteger:currentTimeInter forKey:@"latestCheckTime"];

[[NSUserDefaultsstandardUserDefaults]synchronize];

NSString *urlStr = @"https://itunes.apple.com/lookup?id=1336869336";//1336869336應用的ID

NSURL *url = [NSURL URLWithString:urlStr];

NSURLRequest *req = [NSURLRequestrequestWithURL:url];

[NSURLConnectionconnectionWithRequest:req delegate:self];

}

//1492588093

}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{

NSError *error;

id jsonObject = [NSJSONSerializationJSONObjectWithData:data options:NSJSONReadingAllowFragmentserror:&error];

NSDictionary *appInfo = (NSDictionary *)jsonObject;

NSArray *infoContent = [appInfo objectForKey:@"results"];

if (infoContent.count == 0) {

return;

}

self.version = [[infoContent objectAtIndex:0]objectForKey:@"version"];

NSDictionary *infoDic = [[NSBundlemainBundle]infoDictionary];

NSString *currentVersion = [infoDic objectForKey:@"CFBundleShortVersionString"];

//#warning joe 版本號記得是a.a.aa

NSIntegerlocalVersion = [[currentVersion stringByReplacingOccurrencesOfString:@"."withString:@""] integerValue];

NSInteger latestVersion = [[self.versionstringByReplacingOccurrencesOfString:@"."withString:@""] integerValue];

if (localVersion < latestVersion ) {

self.trackViewUrl = [[infoContent objectAtIndex:0]objectForKey:@"trackViewUrl"];

[self alertViewShow];

}

}

- (void)alertViewShow{

UIAlertView *alertview = [[UIAlertViewalloc]initWithTitle:[[ChangeLanguagebundle] localizedStringForKey:@"new_edition"value:@""table:@"English"] message:self.versiondelegate:selfcancelButtonTitle:[[ChangeLanguagebundle] localizedStringForKey:@"Cancel"value:@""table:@"English"] otherButtonTitles: [[ChangeLanguagebundle] localizedStringForKey:@"Sure"value:@""table:@"English"], nil];

[alertview show];//NSLocalizedString(@"IDS_FIND_NEW_DEVICE",@"發現新版本")NSLocalizedString(@"IDS_ENSURE",@"確定")NSLocalizedString(@"IDS_CANCEL",@"取消")

}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{

if (buttonIndex == 1) {

[[UIApplicationsharedApplication]openURL:[NSURLURLWithString:self.trackViewUrl]];

}

}

@end