app更新

iTunes可以提供app的版本信息，主要通过appid获取，如 http://itunes.apple.com/lookup?id=946449501，使用时只需要到iTunes查找自己的appid，修改成自己的appid即可

使用HTTP模式读取此链接可以获取app信息的json字符串

贴出部分代码

-(void)checkVersion

{

ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:[NSURL URLWithString:strURL]];//strURL为你的appid地址

[request setRequestMethod:@"POST"];

[request setDelegate:self];

[request startAsynchronous];

}

-(void)requestFinished:(ASIHTTPRequest *)request

{

NSString *recStr = [[NSString alloc] initWithData:request.responseData encoding:NSUTF8StringEncoding];

recStr = [recStr stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];//返回的字符串有前面有很多换行符，需要去除一下

NSDictionary *resultDic = [JSONHelper DeserializerDictionary:recStr];//jsonhelper是我封装的json解析类，你可以使用自己方式解析

NSArray *infoArray = [resultDic objectForKey:@"results"];

if (infoArray.count > 0) {

NSDictionary* releaseInfo =[infoArray objectAtIndex:0];

NSString* appStoreVersion = [releaseInfo objectForKey:@"version"];

NSDictionary *infoDic = [[NSBundle mainBundle] infoDictionary];

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

NSArray *curVerArr = [currentVersion componentsSeparatedByString:@"."];

NSArray *appstoreVerArr = [appStoreVersion componentsSeparatedByString:@"."];

BOOL needUpdate = NO;

//比较版本号大小

int maxv = (int)MAX(curVerArr.count, appstoreVerArr.count);

int cver = 0;

int aver = 0;

for (int i = 0; i < maxv; i++) {

if (appstoreVerArr.count > i) {

aver = [NSString stringWithFormat:@"%@",appstoreVerArr[i]].intValue;

}

else{

aver = 0;

}

if (curVerArr.count > i) {

cver = [NSString stringWithFormat:@"%@",curVerArr[i]].intValue;

}

else{

cver = 0;

}

if (aver > cver) {

needUpdate = YES;

break;

}

}

//如果有可用的更新

if (needUpdate){

trackViewURL = [[NSString alloc] initWithString:[releaseInfo objectForKey:@"trackViewUrl"]];//trackViewURL临时变量存储app下载地址，可以让app跳转到appstore

UIAlertView* alertview =[[UIAlertView alloc] initWithTitle:@"版本升级" message:[NSString stringWithFormat:@"发现有新版本，是否升级？"] delegate:self cancelButtonTitle:@"暂不升级" otherButtonTitles:@"马上升级", nil];

[alertview show];

}

}

}

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

{

if (buttonIndex == 1){

UIApplication *application = [UIApplication sharedApplication];

[application openURL:[NSURL URLWithString:trackViewURL]];

}

}