Base UIViewController implements UITableViewDelegate and child view controller as well causing an Exception

I have tried following solution. It may help you...

1. My base class BaseViewController.h code...

#import <UIKit/UIKit.h>
@interface BaseViewController : UIViewController <UITableViewDataSource, UITableViewDelegate>
@property (nonatomic, retain) IBOutlet UITableView *tblBaseClass;
@end

2. My child class ViewController.h code

#import <UIKit/UIKit.h>
#import "BaseViewController.h"
@interface ViewController : BaseViewController
{
    IBOutlet UITableView *tblChildClass;
}
@end

3. My child class ViewController.m code

#pragma mark - Tableview delegate
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    NSInteger count;

    if (tableView == tblChildClass) {

        count = 2;
    }
    else if (tableView == self.tblBaseClass) {

        count = 4;
    }
    return count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *cell;/
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CellIdentifier"];
    /

    NSString *strCellText;

    if (tableView == tblChildClass) {

        strCellText = [NSString stringWithFormat:@"Child class table row : %ld", (long)indexPath.row];
    }
    else if (tableView == self.tblBaseClass) {

        strCellText = [NSString stringWithFormat:@"Base class table row : %ld", (long)indexPath.row];
    }

    cell.textLabel.text = strCellText;

    return cell;
}

In storyboard, add two table view in your child view controller (Here ViewController).

Set IBOutlet to child view controller, also set data source and delegate to child view controller

Here I am not able to show screenshot, otherwise I would like to post for better understanding…sorry… 😟

Thanks for your answer. Do you know the reason for why using ivars instead of property for the child controller?

So, at the end the issue was exactly as explained in the Exeception. I was trying to add the same view as a subview within my table view header view.

[view addSubview:view];

It was a hard to find bug, but thanks to pair programming the issue was resolve. Just be careful with this type of bugs.

🙂