objective C: Using a Delegate to call a function in parent class
I'm creating a 3 layer navigation popup controller and on the 3rd popup controller I have a delegate method to access dismissPopup method that is in the parent class. I can't seem to call it, my NSLog messages in the function in the parent class isn't even showing so I must be either using delegation wrong or I'm calling i开发者_开发问答t incorrectly.
The 3 classes ParentViewController has a toolbar with a button that brings up the table view --> RegionViewController is the First table view controller with items --> ConusViewController is the 2nd table view controller that is pushed onto the navigation stack. I'm trying to call the method dismissPopover that is in the parent method with a delegation after the selection is clicked on so the whole popover goes away.
In the ConusViewController if the delegation had worked I would have seen "Method Accessed" from the function in the parent class. It doesn't show so I must be using delegation wrong.
Sorry for being so wordy on my post, I wanted to be complete on what I'm trying to do here. Thanks.
ParentViewController.h
#import <UIKit/UIKit.h>
#import "ConusViewController.h"
@interface EnscoWXViewController : UIViewController <ConusViewControllerDelegate> {
UIPopoverController *popoverController;
IBOutlet UIWebView *webImageDisplay;
ConusViewController *cViewController;
}
@property (nonatomic, retain) UIPopoverController *popoverController;
@property (nonatomic, retain) UIWebView *webImageDisplay;
@property (nonatomic, retain) ConusViewController *cViewController;
-(IBAction) buttonShowRegion:(id) sender;
@end
ParentViewController.m
#import "ParentViewController.h"
#import "RegionViewController.h"
@implementation ParentViewController
@synthesize cViewController;
-(IBAction) buttonShowRegion:(id) sender {
...
}
-(void)dismissPopover {
[popoverController dismissPopoverAnimated:YES];
printf("Method Accessed\n");
}
- (void)viewDidLoad {
cViewController = [[ConusViewController alloc] init];
cViewController.delegate = self;
[super viewDidLoad];
}
RegionViewController.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
switch (indexPath.row) {
case 0: {
ConusViewController *conusViewController = [[ConusViewController alloc] initWithNibName:@"ConusViewController" bundle:nil];
conusViewController.contentSizeForViewInPopover = CGSizeMake(320, 350);
[self.navigationController pushViewController:conusViewController animated:YES];
[conusViewController release];
break;
}
case 1: {
break;
}
}
}
ConusViewController.h
#import <UIKit/UIKit.h>
@protocol ConusViewControllerDelegate <NSObject>
@required
- (void)dismissPopover;
@end
@interface ConusViewController : UITableViewController {
NSMutableArray *conusItems;
id delegate;
}
@property (nonatomic, assign) id <ConusViewControllerDelegate> delegate ;
@end
ConusViewController.m
#import "ConusViewController.h"
#import "ParentWXViewController.h"
@implementation ConusViewController
@synthesize delegate;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSString *itemRequested = [conusItems objectAtIndex:indexPath.row];
NSLog(@"logging: %@", itemRequested);
[delegate dismissPopover];
[itemRequested release];
}
Just before calling [delegate dismissPopover]
, check if delegate
is actually set. It probably isn't.
I see in ParentViewController.m you create an instance of ConusViewController and set its delegate, but never display it. In RegionViewController.m you create another instance of ConusViewController without setting its delegate and that is the one that seems to be being displayed.
Not sure if I missed it, but I never see you set the delegate property in ConusViewController. That needs to be set to an instance of the object that is to be delegated to (the object that has dismissPopover implemented in it).
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