Ios NSDictionary数据不会传递到另一个ViewController

我需要将2个NSDictionary从一个ViewController传递到另一个ViewController，我的应用程序有时会传递数据，但有时数据不会到达第二个ViewController

我需要咨询web服务两次，web服务响应是JSON，这个JSON（2）是我需要传递给其他ViewController的

对web服务的调用在此处进行（在dispatch\u async中）：

这段代码工作正常，但是，有时在我更改ViewController之后会出现响应（dataResponse），我不知道如果dataResponse没有出现，为什么会更改ViewController

您看，我实例化了第二个ViewController，设置了数据，并在调度_上更改了ViewController（4.0秒）。 为什么我在调度中更改ViewController？因为，如果我不在之后实现dispatch_，NSDictionary总是空的！，这样，NSDictionary有时为空，有时为ok

你能告诉我为什么我的代码有问题吗

---

PS：字典在另一个ViewController中显示为空（没有元素，但不为空）。

这里有一条建议：不要阻塞主线程，不要调用主线程睡眠

这是一个并发问题，方法

setConnectionAndRequest:urlConsultarDisponibilidad

应该是异步的，UI代码可能在两个响应之前执行。我想可以这样解决：

double delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t) (delayInSeconds * NSEC_PER_SEC));
dispatch_queue_t queue = dispatch_queue_create("com.micrologica.modules", nil);

dispatch_async(queue, ^{
    urlConsultarDisponibilidad = [NSString stringWithFormat:connectionUrl getAvailableModuleListAPI, fechaDiaUno, idLocal, idServicioUno, idProfesionalUno, idServicioDos, idProfesionalDos];
    [FunctionsAmano setConnectionAndRequest:urlConsultarDisponibilidad completion:^(NSDictionary *dataResponse) {
        NSLog(@"response dia 1: %@", dataResponse);
        if(dataResponse) {
            NSString *resp = [NSString stringWithFormat:@"%@", [dataResponse objectForKey:@"resp"]];
            if([resp isEqualToString:@"1"]) {
                NSLog(@"almost finish 1");
                modulesDiaUno = [dataResponse objectForKey:@"data"];
            }

            dispatch_after(popTime, queue, ^(void){
                finishedDiaUno = YES;
                NSLog(@"finished 1");

                if (finishedDiaDos) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        HorariosViewController *horariosView = [self.storyboard instantiateViewControllerWithIdentifier:@"ModulesView"];
                        horariosView.modulesDiaUno = self.modulesDiaUno;
                        horariosView.modulesDiaDos = self.modulesDiaDos;
                        [self presentViewController:horariosView animated:NO completion:nil];
                    });
                }
            });
        }
    }];
});

dispatch_async(queue, ^{
    urlConsultarDisponibilidad = [NSString stringWithFormat:connectionUrl getAvailableModuleListAPI, fechaDiaDos, idLocal, idServicioUno, idProfesionalUno, idServicioDos, idProfesionalDos];
    [FunctionsAmano setConnectionAndRequest:urlConsultarDisponibilidad completion:^(NSDictionary *dataResponse) {
        NSLog(@"response dia 2: %@", dataResponse);
        if(dataResponse) {
            NSString *resp = [NSString stringWithFormat:@"%@", [dataResponse objectForKey:@"resp"]];
            if([resp isEqualToString:@"1"]) {
                NSLog(@"almost finish 2");
                modulesDiaDos = [dataResponse objectForKey:@"data"];
            }

            dispatch_after(popTime, queue, ^(void){
                finishedDiaDos = YES;
                NSLog(@"finished 2");

                if (finishedDiaUno) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        HorariosViewController *horariosView = [self.storyboard instantiateViewControllerWithIdentifier:@"ModulesView"];
                        horariosView.modulesDiaUno = self.modulesDiaUno;
                        horariosView.modulesDiaDos = self.modulesDiaDos;
                        [self presentViewController:horariosView animated:NO completion:nil];
                    });
                }
            });
        }
    }];
});

---

“空”是什么意思

horariosView.modulesDiaUno

存在，但没有元素或元素为零。你好，KudoCC，我用另一段代码实现了信息。谢谢可能重复我正在测试你的代码，这似乎可行，但我有一个问题，在你的代码中，我打了两次电话来更改ViewController？一次finishDiaUno为是，一次finishedDiaDos为是，这会影响到某些东西？它不会调用两次，因为队列是串行的，如果第一个响应先到，

finishedDiaUno

将首先设置为是，但

finishedDiaDos

为否，因此不会显示ViewController，然后第二个反应来了，finishedDiaUno和finishedDiaDos都是YES，将会出现viewcontroller。太棒了！非常感谢你！，我做了40次测试，没有一次不及格！！！在你帮助我之前，我的代码失败了4到5次！非常感谢你！建议阅读：谢谢，我知道我需要阅读有关IOS编程的内容，我只在IOS上编程了2周，但问题解决后，应用程序就完成了！，现在我有时间读书和学习：）

double delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t) (delayInSeconds * NSEC_PER_SEC));
dispatch_queue_t queue = dispatch_queue_create("com.micrologica.modules", nil);

dispatch_async(queue, ^{
    urlConsultarDisponibilidad = [NSString stringWithFormat:connectionUrl getAvailableModuleListAPI, fechaDiaUno, idLocal, idServicioUno, idProfesionalUno, idServicioDos, idProfesionalDos];
    [FunctionsAmano setConnectionAndRequest:urlConsultarDisponibilidad completion:^(NSDictionary *dataResponse) {
        NSLog(@"response dia 1: %@", dataResponse);
        if(dataResponse) {
            NSString *resp = [NSString stringWithFormat:@"%@", [dataResponse objectForKey:@"resp"]];
            if([resp isEqualToString:@"1"]) {
                NSLog(@"almost finish 1");
                modulesDiaUno = [dataResponse objectForKey:@"data"];
            }

            dispatch_after(popTime, queue, ^(void){
                finishedDiaUno = YES;
                NSLog(@"finished 1");

                if (finishedDiaDos) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        HorariosViewController *horariosView = [self.storyboard instantiateViewControllerWithIdentifier:@"ModulesView"];
                        horariosView.modulesDiaUno = self.modulesDiaUno;
                        horariosView.modulesDiaDos = self.modulesDiaDos;
                        [self presentViewController:horariosView animated:NO completion:nil];
                    });
                }
            });
        }
    }];
});

dispatch_async(queue, ^{
    urlConsultarDisponibilidad = [NSString stringWithFormat:connectionUrl getAvailableModuleListAPI, fechaDiaDos, idLocal, idServicioUno, idProfesionalUno, idServicioDos, idProfesionalDos];
    [FunctionsAmano setConnectionAndRequest:urlConsultarDisponibilidad completion:^(NSDictionary *dataResponse) {
        NSLog(@"response dia 2: %@", dataResponse);
        if(dataResponse) {
            NSString *resp = [NSString stringWithFormat:@"%@", [dataResponse objectForKey:@"resp"]];
            if([resp isEqualToString:@"1"]) {
                NSLog(@"almost finish 2");
                modulesDiaDos = [dataResponse objectForKey:@"data"];
            }

            dispatch_after(popTime, queue, ^(void){
                finishedDiaDos = YES;
                NSLog(@"finished 2");

                if (finishedDiaUno) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        HorariosViewController *horariosView = [self.storyboard instantiateViewControllerWithIdentifier:@"ModulesView"];
                        horariosView.modulesDiaUno = self.modulesDiaUno;
                        horariosView.modulesDiaDos = self.modulesDiaDos;
                        [self presentViewController:horariosView animated:NO completion:nil];
                    });
                }
            });
        }
    }];
});