UITableView Passing Data Between Controllers Embedded Inside Containers

问题

I have a simple test project. A UITableViewController (MasterViewController) embedded inside a navigation controller in storyboard. I am NOT segueing using the prepareForSegue to pass data to another view controller (DetailViewController). Instead, didSelectRowAtIndexPath is use to update a label in the detailviewcontroller as below:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    DetailViewController *detailViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"DetailViewController"];
    NSMutableString *object = thisArray[indexPath.row];

    detailViewController.passedData = object;
    [self.navigationController pushViewController:detailViewController animated:YES];
}

Everything till this point works fine.

Now i have added another view controller in my storyboard. Made it the initial view controller, added two containers in it, then embedded both MasterViewController and DetailViewContainer in these containers.

Now instead of showing passed data inside the DetailViewController on the right side, its showing the passed data on the left side by replacing the controller view.

If i am not able to clarify what i am trying to say, here is the link to the project https://jumpshare.com/v/UiTFEB6AamIo8qX9sinW , its just for learning purpose.

Thanks

回答1:

You're getting this problem because you are still doing this:

[self.navigationController pushViewController:detailViewController animated:YES];

The navigation controller you're referencing here is the one your master controller is embedded in, so you create an instance (different than the one that's already on screen) of detailController and push that onto the navigation controller.

What you want to do, is get a reference to the detail controller that's already on screen -- both child view controllers (the ones in the container views) are already instantiated when the app starts. So, you need to do this:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    DetailViewController *detailViewController = [self.navigationController.parentViewController childViewControllers][1];
    NSMutableString *object = thisArray[indexPath.row];
    detailViewController.passedData = object;
}

This will pass the value to the detail controller, but you can't have the code to update the label in viewDidLoad, since that view is already loaded, and won't be called again. Instead, override the setter for passedData, and update the label there (note that I changed the name of the argument to passedInData, so it doesn't conflict with your property passedData):

-(void)setPassedData:(NSString *)passedInData {
    passedData = passedInData;
    detailDescriptionLabel.text = passedData;
}

Bu the way, unless you're planning on adding other controllers after your master view controller, there's no reason to have it embedded in a navigation controller at all, given this set up. If you take it out, then you need to remove the reference to self.navigationController when you get the reference to the detail controller. It would then just be:

DetailViewController *detailViewController = [self.parentViewController childViewControllers][1];

来源：https://stackoverflow.com/questions/16381278/uitableview-passing-data-between-controllers-embedded-inside-containers

标签

ios

objective-c

uitableview

storyboard