如何刷新我从iOS中的谷歌oauth 2.0获得的令牌

我正在制作一个iOS应用程序,它使用用户的谷歌帐户从他的YouTube帐户中获取数据并显示它们….第一步是使用gtm2来validation用户并获取access-token和刷新令牌问题是访问令牌在60分钟后到期,我必须登录并再次允许应用程序…我发现您可以使用刷新令牌从文档中使用此获取新的访问令牌: – >我的问题是如何发出POST请求以获取Objective-c中的访问令牌这是我需要使用的数据:

POST /o/oauth2/token HTTP/1.1 Host: accounts.google.com Content-Type: application/x-www-form-urlencoded client_id=21302922996.apps.googleusercontent.com& client_secret=XTHhXh1SlUNgvyWGwDk1EjXB& refresh_token=1/6BMfW9j53gdGImsixUH6kU5RsR4zwI9lUVX-tqf8JXQ& grant_type=refresh_token 

这是我正在使用的代码:

 NSString *post =[[NSString alloc] initWithFormat:@"client_secret=%@&grant_type=refresh_token&refresh_token=%@&client_id%@",kGoogleClientSecretKey,kRefreshToken,kGoogleClientIDKey]; NSLog(@"%@",post); NSURL *url=[NSURL URLWithString:@"https://accounts.google.com/o/oauth2/token"]; NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES]; NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ; [request setURL:url]; [request setHTTPMethod:@"POST"]; [request setValue:postLength forHTTPHeaderField:@"Content-Length"]; [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [request setHTTPBody:postData]; NSError *error; NSURLResponse *response; NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error]; NSString *data=[[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding]; NSLog(@"%@",data); 

我得到的错误是:{“error”:“invalid_request”}

您在格式字符串中缺少a =

更改

 NSString *post =[[NSString alloc] initWithFormat:@"client_secret=%@&grant_type=refresh_token&refresh_token=%@&client_id%@",kGoogleClientSecretKey,kRefreshToken,kGoogleClientIDKey]; 

 NSString *post =[[NSString alloc] initWithFormat:@"client_secret=%@&grant_type=refresh_token&refresh_token=%@&client_id=%@",kGoogleClientSecretKey,kRefreshToken,kGoogleClientIDKey];