从另一个类Objective-C调用方法

Question

So far the remote wipe works, but I'm having trouble starting a backup in the background. The remote wipe also works in the background. I am trying to call the startBackgroundBackupActivity method from my locationHandler class which works in the background.

BackgroundBackupHandler.m

- (void) OnSyncComplete:(NSNumber*)result message:(NSString *)message{
    NSLog(@"-(void)OnSyncComplete:%@ message=%@",result, message);
    //jxxtodo: Ensure all existing objects are reset, including DB and network connections
    if (0 == [result intValue]){
        NSString *strMsg = [ErrorHandler getErrorTextByErrorNumber:SYNC_SUCCESS_INF withObjects:nil];
        [self logEvent:strMsg];
    }else if (2 == [result intValue]){//no sync required
        NSString *strMsg = [ErrorHandler getErrorTextByErrorNumber:NO_NEED_SYNC_INF withObjects:nil];
        [self logEvent:strMsg];
    }else if (3 == [result intValue]) {
        NSString *strMsg = [ErrorHandler getErrorTextByErrorNumber:SYNC_RESET_EMPTY_INF withObjects:nil];
        [self logEvent:strMsg];
    } else{
        NSString *strMsg = [ErrorHandler getErrorTextByErrorNumber:SYNC_COMMON_ERR withObjects:nil];
        [self logEvent:strMsg];

        return;
    }
    [m_pSyncController release];
    m_pSyncController = nil;
    self.m_backupSet = nil;
    [self performSelector:@selector(startBackgroundBackupActivity) withObject:nil afterDelay:1.5];
}

Right now, OnSyncComplete:message: is what calls startBackupActcitivy from within the BackgroundBackupHandler class.

I have another class LocationHandler which checks the flag sent from the server and does something based on the flag. So if the flag is set to backup then wipe, it will run a backup then wipe the device.

How would I call OnSyncComplete:message: from the LocationHandler class.

Ive tried:

BackgroundBackupHandler *bgBackup = [[BackgroundBackupHandler alloc]init];
[bgBackup OnSyncComplete:[NSNumber numberWithInt:3] message:nil];

This is giving me errors and terminating my application. Is there anyway to call startBackgroundBackupActivity from the LocationHandlerClass .

The error is that the application crashed and aborts. NSInvalidArgumentException, where nil is not a legal NSManagedObjectContext. The locationHandler will start a background task, which will then sync the device and return control to the OnSyncComplete method in the LocationHandler class which then in turn calls the OnSyncComplete in the BackgroundBackupHandler class.

Answer 1

The 2 ways to create communication between object are: 1) delegations 2) notifications

In your case it seems like the notification can work better. Check this out