卡在这个 while 循环中

Question

为什么我的 loginAuth 卡在 while 循环中？

我将 connectionFinishLoading 声明为

@interface LoginViewController : UIViewController {   
    BOOL connectionFinishLoading;
}
@property (nonatomic, assign) BOOL connectionFinishLoading;

@implementation LoginViewController
@synthesize connectionFinishLoading;

 -(BOOL)loginAuth {

    NSString *requestString = [NSString stringWithFormat:@"http:myURL?id=%@&format=JSON", userName.text];
    NSMutableURLRequest *requestURL = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:requestString]];
    loginConnection = [[NSURLConnection alloc] initWithRequest:requestURL delegate:self startImmediately:YES];
    [SVProgressHUD showInView:self.view status:@"Logging in"];
    while (!connectionFinishLoading) {
        NSLog(@"waiting..");
    }
     // code to executed after connection did finish loading.
}

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

    [responseData appendData:data];
}


- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    connectionFinishLoading = YES;
}

Answer 1

因为您阻塞了运行循环并且没有数据包通过网络发送，因此连接永远不会完成。

Answer 2

尝试添加这个：

- (void)connection:(NSURLConnection *)conn didFailWithError:(NSError *)error
// A delegate method called by the NSURLConnection if the connection fails. 
// Production quality code would either display or log the actual error.
{
   #pragma unused(conn)
   #pragma unused(error)
   assert(conn == self.connection);

   NSLog(@"didFailWithError %@", error);

   connectionFinishLoading = YES;
}

但是创建这样的循环是非常糟糕的做法

Answer 3

正如 JustSid 提到的，运行循环被阻塞。我建议摆脱“while”循环和 BOOL connectionDidFinishLoading 属性，然后将要执行的代码移动到 connectionDidFinishLoading 方法中。您仍然应该以某种方式处理连接失败块。

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    // code to executed after connection did finish loading.
}