Question

我正在构建一个使用AFNetworking重复调用Web服务的聊天应用程序。聊天屏幕不断轮询此服务以获取新的聊天消息。与服务相关的所有内容都可以正常工作，但UI会一直冻结，并且没有任何按钮正常工作。

以下是代码：

- (void)GetAllIncomingMessages
{
    NSURL *url = [NSURL URLWithString:weatherUrl];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    AFJSONRequestOperation *operation =
    [AFJSONRequestOperation JSONRequestOperationWithRequest: request
                                                    success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

                                                        [self ParseJson:(NSDictionary *)JSON];
                                                        [self GetAllIncomingMessages];


                                                    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON)

                                                    {
                                                        [self GetAllIncomingMessages];
                                                        UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error "
                                                                                                     message:[NSString stringWithFormat:@"%@",error]
                                                                                                    delegate:nil
                                                                                           cancelButtonTitle:@"OK" otherButtonTitles:nil];
                                                        [av show];
                                                    }];
    [operation setAuthenticationChallengeBlock:
     ^( NSURLConnection* connection, NSURLAuthenticationChallenge* challenge )
     {
         if( [[challenge protectionSpace] authenticationMethod] == NSURLAuthenticationMethodHTTPBasic )
         {
             if( [challenge previousFailureCount] > 0 )
             {
                 // Avoid too many failed authentication attempts which could lock out the user
                 [[challenge sender] cancelAuthenticationChallenge:challenge];
             }
             else
             {
                 [[challenge sender] useCredential:[NSURLCredential credentialWithUser:@"username" password:@"password" persistence:NSURLCredentialPersistenceForSession] forAuthenticationChallenge:challenge];
             }
         }
         else
         {
             // Authenticate in other ways than NTLM if desired or cancel the auth like this:
             [[challenge sender] cancelAuthenticationChallenge:challenge];
         }
     }];
    [operation start];
}

我每次都重新加载表视图，但UI仍然冻结。我尝试使用后台线程，但也没有用。

Answer 1

我知道这是一个古老的问题，但我只是碰到了它。只是FYI AFNetworking使用调度的异步队列来执行连接操作，并在主队列中返回检索到的NSData的JSON格式（您可能已经知道）。所以AFNetworking肯定不是问题。

我的建议是尝试执行ParseJson：和GetAllIncomingMessages：在一个单独的线程中或自己调度一个异步队列，你会看到你的UI不再冻结。

类似的东西：

static dispatch_queue_t your_app_queue() {
    static dispatch_once_t onceToken;
    static dispatch_queue_t _myQueue;
    dispatch_once(&onceToken, ^{
        _myQueue = dispatch_queue_create("com.myapp.queue", DISPATCH_QUEUE_SERIAL);
    });
    return _myQueue;
}

AFJSONRequestOperation *operation =
[AFJSONRequestOperation JSONRequestOperationWithRequest: request
                                                success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

                                                    __block myClass = self;
                                                    dispatch_async(your_app_queue(), ^{

                                                        [myClass ParseJson:(NSDictionary *)JSON];
                                                        [myClass GetAllIncomingMessages];
                                                    });
                                                }
                                                failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON){

                                                    __block myClass = self;
                                                    dispatch_async(your_app_queue(), ^{

                                                           [myClass GetAllIncomingMessages];
                                                           dispatch_async(dispatch_get_main_queue(), ^{

                                                               UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error "
                                                                                                            message:[NSString stringWithFormat:@"%@",error]
                                                                                                           delegate:nil
                                                                                                  cancelButtonTitle:@"OK" otherButtonTitles:nil];
                                                               [av show];
                                                           });
                                                    });
                                                }];

或者：

AFJSONRequestOperation *operation =
[AFJSONRequestOperation JSONRequestOperationWithRequest: nil
                                                success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {

                                                    [self performSelectorInBackground:@selector(ParseJson:) withObject:JSON];
                                                    [self performSelectorInBackground:@selector(GetAllIncomingMessages) withObject:nil];
                                                }
                                                failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON){

                                                    [self performSelectorInBackground:@selector(GetAllIncomingMessages) withObject:nil];

                                                    UIAlertView *av = [[UIAlertView alloc] initWithTitle:@"Error "
                                                                                                 message:[NSString stringWithFormat:@"%@",error]
                                                                                                delegate:nil
                                                                                       cancelButtonTitle:@"OK" otherButtonTitles:nil];
                                                    [av show];
                                                }];

应该没事。希望这有帮助！

AFNetworking冻结了其他行动

1 个答案: