版本更新检测

---

现在大部分应用都有版本更新检测，当有新版本时弹出提示用户更新，有时还需要强制更新（很少用，影响体验）。
更新之后，最好清理本地的缓存数据，因为新版本有可能对某些数据对象结构有更改，上一版本缓存的数据结构不能满足。

构造一个版本信息的类

typedef NS_ENUM(NSInteger, PGVersionUpdateType) {
    VERION_UPDATE_TYPE_NONE = 1,//没有更新
    VERION_UPDATE_TYPE_OPTIONAL,//可选更新
    VERION_UPDATE_TYPE_FORCE,//强制更新
};

@interface PGVersionObject : PGBaseObj

/*
 版本号
 */
@property(nonatomic, strong)NSString *szVersion;
/*
 更新地址
 */
@property(nonatomic, strong)NSString *szUrl;
/*
 更新内容简述
 */
@property(nonatomic, strong)NSString *szDesc;
/*
 0:没有更新，1：有更新，2：强制更新
 */
@property(nonatomic, assign)PGVersionUpdateType updateType;

@end

版本检测，弹框提示我都放到个类里面处理了：

@interface PGVersionManager : NSObject

/*
 检测版本更新
 */
+ (void)checkVersion;

@end

#define VERSION_RETRY_COUNT 5

@interface PGVersionManager ()<PGApiDelegate>
/*
 上次检测更新的时间
 */
@property(nonatomic, strong)NSDate *lastCheckDate;
/*
 是否有强制更新
 */
@property(nonatomic, assign)BOOL needUpdate;
/*
 检测版本失败重试次数
 */
@property(nonatomic, assign)NSInteger nRetryCount;

@end

@implementation PGVersionManager

+ (PGVersionManager *)shareInstance
{
    static PGVersionManager *s_versionManager = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        s_versionManager = [[PGVersionManager alloc] init];
    });
    return s_versionManager;
}

- (id)init
{
    if(self = [super init])
    {
        self.needUpdate = NO;
        self.lastCheckDate = nil;
        self.nRetryCount = VERSION_RETRY_COUNT;
    }
    return self;
}

+ (void)checkVersion
{
    [PGVersionManager shareInstance].nRetryCount = VERSION_RETRY_COUNT;
    if([PGVersionManager shareInstance].needUpdate ||
       [PGVersionManager shareInstance].lastCheckDate == nil ||
       [NSDate numDayFromDate:[PGVersionManager shareInstance].lastCheckDate toDate:[NSDate date]] >= 1)
    {
        [[PGVersionManager shareInstance] getVersionInfo];
    }
}

- (void)getVersionInfo
{
    NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
    [PGRequestManager startPostClient:API_TYPE_VERSION_CHECK param:@{@"app_version":version} target:self extendParam:nil];
}

#pragma mark - PGApiDelegate
- (void)dataRequestFinish:(PGResultObject *)resultObj apiType:(PGApiType)apiType
{
    if(resultObj.nCode == 0)
    {
        self.lastCheckDate = [NSDate date];
        PGVersionObject *versionObj = (PGVersionObject *)resultObj.dataObject;
        
        if(versionObj.updateType == VERION_UPDATE_TYPE_OPTIONAL)
        {
            [[PGApp appRootController] showAskAlertTitle:[NSString stringWithFormat:@"发现新版本:%@",versionObj.szVersion] message:versionObj.szDesc tag:1000 action:^(NSInteger alertTag, NSInteger actionIndex) {
                if(actionIndex == 0) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:versionObj.szUrl]];
                    });
                }
            } cancelActionTitle:@"更新" otherActionsTitles:@"取消",nil];
        }
        else if(versionObj.updateType == VERION_UPDATE_TYPE_FORCE)
        {
            [[PGApp appRootController] showAskAlertTitle:[NSString stringWithFormat:@"发现新版本:%@",versionObj.szVersion] message:versionObj.szDesc tag:1000 action:^(NSInteger alertTag, NSInteger actionIndex) {
                if(actionIndex == 0) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:versionObj.szUrl]];
                    });
                }
            } cancelActionTitle:@"更新" otherActionsTitles:nil];
        }
    }
    else
    {
        //失败重试
        if(self.nRetryCount > 0)
        {
            self.nRetryCount -= 1;
            [self getVersionInfo];
        }
    }
}

@end

更新完成后最好清理本地缓存，这时只需在PGCacheManager里面添加一函数方法就可以了。

+ (void)clearCacheDataForNewVersion
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    int bClear = [[defaults stringForKey:@"bCacheClear"] intValue];
    NSInteger oldVersion = [defaults integerForKey:@"currentVersion"];
    NSString *version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleVersion"];
    NSInteger nVersion = [version integerValue];
    if(bClear == 0 || nVersion > oldVersion)
    {
        [PGCacheManager clearCacheData:nil];
        
        [defaults setObject:@"1" forKey:@"bCacheClear"];
        [defaults setInteger:nVersion forKey:@"currentVersion"];
        [defaults synchronize];
    }
}

在AppDelegate里面调用

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    
    //清除缓存
    [PGCacheManager clearCacheDataForNewVersion];
    
    ......
    
    return YES;
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
    /*
     检测版本更新 
     */
    [PGVersionManager checkVersion];
}