当我编写代码时,似乎无法使Delegate回调工作。我试图使用NSURLConnection调用远程服务器来获取access_token。 access_token在connection:didReceiveResponse:delegate中收到。在我发布它之前,这不是问题。我以为我正在为我的代表传递正确的对象,但它没有达到连接:didReceiveResponse:
任何人都可以看到为什么连接:didReceiveResponse:在我调用线程时没有调用LoginViewController?感谢。
LoginViewController.m
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
NSString *access_token = [self getTokenFromResponse: response];
[self.delegate didGetAccessToken:access_token];
}
- (void)fetchAccessTokenNoUI
{
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString: @"www.mysite.com"]];
[NSURLConnection connectionWithRequest:request delegate:self];
}
AccessToken.h
@interface AccessToken : NSObject
@property (atomic, strong) LoginViewController *loginViewController; // doing this to try to keep it persistent
- (void) fetchAccessTokenWithDelegate: (id <LoginDelegate>)delegate;
@end
AccessToken.m
- (void) fetchAccessTokenWithDelegate: (id < LoginDelegate >)delegate
{
dispatch_queue_t downloadQueue = dispatch_queue_create("Fetch access_token queue", NULL);
dispatch_async(downloadQueue, ^ {
// this works fine if I don't do it in a queue
self.loginViewController = [[LoginViewController alloc] init];
self.loginViewController.delegate = delegate;
[self.loginViewController fetchAccessTokenNoUI];
});
dispatch_release(downloadQueue);
}
CallingClass.m
- (void)didGetAccessToken:(NSString *)access_token
{
if (!access_token)
{
LoginViewController *userProfileViewController = [[LoginViewController alloc] init];
userProfileViewController.delegate = self;
[self.navigationController pushViewController:userProfileViewController animated:YES];
}
}
- (IBAction)favourite:(id)sender
{
AccessToken *accessToken = [[AccessToken alloc] init];
[accessToken fetchAccessTokenWithDelegate:self];
}
答案 0 :(得分:0)
您是否设置了存根来实现所需的协议方法,
-(void)connectionDidFinishLoading:(NSURLConnection *)connection;
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data;
因为我有类似的问题在实施后就消失了。
答案 1 :(得分:0)
经过一些研究,我找到了解决方案。
我实际上并不需要AccessToken.h / m。我以为NSURLConnection调用会阻止我的UI线程。但NSURLConnection connectionWithRequest:delegate:自动在一个单独的线程中运行。
所以我要做的就是删除AccessToken.h和AccessToken.m。然后,在CallingClass.m中,我改变了favourte:to
- (IBAction)favourite:(id)sender
{
LoginViewController *loginViewController = [[LoginViewController alloc] init];
[loginViewController fetchAccessTokenWithDelegate:self];
}
就是这样!根本不需要dispatch_queue_t。