Give NSString to other class on segue

Question

In one class there is a list with all friends and their IDs. Now when you click on the item in the UITableView the Chat appears ([self performSegueWithIdentifier: @"showChat" sender: self];). But in the ChatViewController Class I need to access the variable userID from FirstViewController. I tried everything I found on the internet, but it always gives an error or the variable is empty. In FirstViewController is a NSString userid, so how can I access this in ChatViewController.m? I tried to make the variable @public, I tried @property with readwrite and so on, but it doesn't work. For example this:

FirstViewController *fvc = [[FirstViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];
userID = fvc.userID;

just gives an empty String..

Thanks for help!

score 4 · Accepted Answer · edited May 23 '17 at 11:43

You need to have prepareForSegue: method to pass the variable.

Implement the method as follows:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    // Make sure your segue name in storyboard is the same as this line
    if ([[segue identifier] isEqualToString:@"showChat"])
    {
        // Get reference to the destination view controller
        ChatViewController *cvc = [segue destinationViewController];

        // Set the object to the view controller here, like...
        cvc.userID = self.userID;
    }
}

You can find the tutorial here on passing the value through segue.

Update

Similar question is already asked here

score 3 · Answer 2 · answered Apr 09 '12 at 11:07

You write this code in ChatViewController right . where u make a new instance of FirstViewController. And this is the problem new instance has userID always empty.

FirstViewController *fvc = [[FirstViewController alloc] initWithNibName:@"FirstViewController" bundle:nil];
userID = fvc.userID;

U need to have ur old instance of FirstViewController or when u go FirstViewController to ChatViewController u have to pass this value to userID = fvc.userID;

    ChatViewController *cvc = [ChatViewController new];
    cvc.userID = self.userID;
[self.navigationController pushViewController:cvc animated:YES];

Bear in mind that u have set Property and synthesize the userID in ChatViewController.

Give NSString to other class on segue

2 Answers2