Question

当可以访问webservice时，代码工作正常，但是当它无法访问时，应用程序崩溃。为什么控件没有进入@catch ??

-(void)callRegisterWebService:(NSString *)fname lastName:(NSString *)lName email:(NSString *)email
{
    [self.view endEditing:YES];
    UIActivityIndicatorView *activity = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    [self.view addSubview:activity];

    activity.center = self.view.center;
    [self.view bringSubviewToFront:activity];
    activity.hidesWhenStopped = YES;
    [activity setHidden:NO];

    [activity startAnimating];

    NSOperationQueue *q = [NSOperationQueue mainQueue];

    NSString *serviceURL = [NSString stringWithFormat:@"https://aagaka];

        NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:serviceURL]];
    @try
    {
    [NSURLConnection sendAsynchronousRequest:request queue:q completionHandler:^(NSURLResponse *serviceResponse, NSData *responseData, NSError *err) {

        NSMutableDictionary *parsedData = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:&err];
        [activity stopAnimating];
        if(!parsedData)
        {
            NSLog(@"data not parsed");
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"ERROR" message:@"Problem in Network. Please Try Again!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
            [alert show];

        }
        else
        {
            NSLog(@"parsed");
            NSLog(@"parsed.. the size is %lu", (unsigned long)[parsedData count]);
            NSLog(@"%@", parsedData);

            NSString *status = [parsedData objectForKey:@"Status"];
            NSLog(@"the status is %@", status);

            if([status isEqualToString:@"Success"])
            {
                NSString *uniqueNumber = [parsedData objectForKey:@"UniqueNum"];
                [self saveEmailAndUniqueNumberToDatabase:fname lastName:lName Email:email Number:uniqueNumber];

                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NULL message:@"Authentication Token Has Been Sent To Your Email-ID!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
                [alert show];

                [self.verifyView setHidden:NO];
                [self.registerView setHidden:YES];
                [self.verifyButtonTab setEnabled:YES];

                [self.verifyButtonTab setSelected:YES];
                [self.registerButtonTab setSelected:NO];
            }
            else if([status isEqualToString:@"Failed"])
            {
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Not An Authorized User" message:@"Please Contact Admin To Get Access" delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil];
                [alert show];

                [self.verifyView setHidden:YES];
                [self.registerView setHidden:NO];
                [self.verifyButtonTab setEnabled:NO];
                [self.registerButtonTab setSelected:YES];
            }
            else
            {
                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"ERROR" message:@"Problem in Network. Please Try Again!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
                [alert show];
                [self.verifyView setHidden:YES];
                [self.registerView setHidden:NO];
                [self.verifyButtonTab setEnabled:NO];

                [self.registerButtonTab setSelected:YES];
            }
        }
    }];
}
    @catch (NSException *exception)
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NULL message:@"Problem In Network Connection. Please Try Again!" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
        [self.verifyView setHidden:YES];
        [self.registerView setHidden:NO];
        [self.verifyButtonTab setEnabled:NO];
        [self.registerButtonTab setSelected:YES];
    }
    @finally {

    }
}

Answer 1

如果te阻塞发生错误，则try catch将不会被调用，因为块在不同的上下文中执行。

在completionHandler:的块中移动try try catch，它应该可以工作。

应用程序崩溃。控制不移动到catch语句

1 个答案: