尝试使用NSURL在objC中进行GET请求

我正在尝试在iOS应用中提出此请求

我已经使用登录了网站NSURLConnection，以下代码位于完成处理程序中：

NSMutableURLRequest *requestGrades = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:@"https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/LoadProfileData/Assignments?_=1395809728907"]];
[requestGrades setHTTPMethod:@"GET"];
[NSURLConnection sendAsynchronousRequest:requestGrades queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *gradeResponse, NSData *gradeData, NSError *gradeError) {
    
    if ([gradeData length] > 0 && gradeError == nil) {
        NSLog(@"%@",requestGrades);
        NSLog(@"grade Response = %@ \ngrade Data = %@", gradeResponse, [[NSString alloc] initWithData:gradeData encoding:NSUTF8StringEncoding]);
    } else {
        NSLog(@"grade Error = %@", gradeError);
    }
}];

我在应用程序中得到的响应类似于：

grade Response = <NSHTTPURLResponse: 0x109627500> { URL: https://mistar.oakland.k12.mi.us/novi/StudentPortal/Home/LoadProfileData/Assignments?_=1395809728907 } { status code: 200, headers {
    "Cache-Control" = "public, max-age=0";
    Connection = "Keep-Alive";
    "Content-Length" = 234;
    "Content-Type" = "text/html; charset=utf-8";
    Date = "Wed, 26 Mar 2014 05:21:52 GMT";
    Expires = "Wed, 26 Mar 2014 05:21:52 GMT";
    "Last-Modified" = "Wed, 26 Mar 2014 05:21:52 GMT";
    Server = "Microsoft-IIS/7.5";
    Vary = "*";
    "X-AspNetMvc-Version" = "4.0";
    "X-Powered-By" = "ASP.NET";
} } 

如您所见，它与Chrome的响应不同（最明显的是Content-Length-我只有234的长度-我希望能得到31189之类的东西）。

Network在chrome开发人员工具的部分中进行浏览，看看当我尝试请求数据时chrome的作用是：

Chrome, when I click the button to fetch some data, makes 2 GET requests (the two pictures). The first one gets the data I'm trying to get for my app and the second which seems as if it doesn't really do anything. BUT the response the second chrome request is getting is the same response that I get when I try to make the first chrome request from iOS (the first picture, should return a Content-Length of 31189).

So I'm not sure what I'm doing wrong with my NSURLConnection.